>>> 20may03 #11298-18250 +++ #11397 From: pfflyerz@c... Subject: Re: Forming the Firewall I made two firewalls. The first one came out beautiful. I then proceeded to screw it up by trying to roll some stiffening beads in it like Bob has. With the flange already formed, I wasn't able to run the bead all the way to the edge. The firewall took on a pretzel shape and I wasn't able to find a way to relieve the stresses keeping it from going back to flat. My second firewall also came out beautiful, and I left the beads off. I may rivet a stiffener angle to it, and I may not, haven't yet decided. I cut crimping notches in the sides of my form block so I was able to bend the flange and crimp it all in one operation. When I removed it from the form block it was perfectly flat. Pat Fagan #232 Pearblossom, CA +++ #11408 From: fmuder@a... Subject: Re: Forming the Firewall We made, from sratch, a crossover exhaust system for an 0-360 Lycoming. It is not a thing of beauty but works well. What we were most pleased about is the sound of it. There is not a "raspy", unpleasant, objectionable sound to it even without a muffler. Apparently, the sound waves tend to cancel each other while providing some efficiency in tuning. We used 321 stainless, .049 wall thickness 1.75" into 2.125" at the tail. We got the stainless from a California supplier who caters to the auto "motorheads". Prices seemed good at the time (1997). If you would like more info, I'd be glad to pass on. I know you're a north of the border brother and understand the cost differences. Fred&Shelly, Hatz, Christavia&Mt.Goat, Bearhawk#311. +++ #11464 From: "fourthwedge" Subject: Neat Link Found this link and learned a little more. The 1st link on the page is a real motor-head article (Mr. Barretts' name appears again and the engine pics will make you drool); but the portion about starters, near the end, should be especially interesting to anybody running a Lycoming. The photo tour of the Pitts factory is mighty interesting. Some of the fixtures might be worth copying. Looks to me like Budds' operation in Mexico is right up there with the big boys if not a shade or two ahead. http://musclebiplane.org/htmlfile/builders.shtml Let's see you grow one of these 300 HP 540's PB!! I'll take half-a- dozen of those magic beans. Dave +++ #11472 From: charles.k.scott@d... Subject: Re: Digest Number 908 > It won't help--all of the techniques Deakin espouses require a fuel > injected engine fitted with GAMIjectors. That pretty much limits it > to big fuel injected Continentals. Carbureted engines have a much > poorer mixture distribution and therefore it won't work. Read the > articles to understand why. Erbman is likely correct. The only help Deakin could offer for those with carburated engines is to climb to around 7500 to 8000 feet, where you could push the throttle to wide open and get about 65% power from the engine, where he recommends the following: Push the throttle to wide open and then bring it back slightly. This cocks the throttle plate slightly which imparts a bit of a swirl to the incoming fuel/air mixture. He said this is the best you can hope for. The problem is that fuel distribution with carburated engines is so bad that you cannot normally lean past peak without getting terrible roughness in the engine. If the fuel distribution were relatively equal, you should be able to lean the engine without roughness right to the point where the engine simply quits because the mixture is too lean to ignite at that point. The other problem is that it's difficult to lean properly without one of those multi cylinder EGT guages that tells you what's happening in each individual combustion chamber. It makes for very very interesting reading, and also makes you want the GAMI fuel injectors. When you say that you are leaning rich of peak, what you are describing, according to Deakin, is running the engine very close to peak temperature - continuously. That may not be a good thing. Corky Scott +++ #11563 From: "zipppydoggg" Subject: Radial Engine operations Did you guys read the information on the web about the care and operation of the russian radial engines? Engines are neet and all but the part that caught my attention was the possibility of undetected engine damage as well as the care required to keep oil out of the intake. All that work to go fly compared the operation of a flat engine, not worth the work. I guess I'm spoiled. I just want to do the pre-flight as quickly as reasonably possible, turn the key, and go fly. Wouldn't want to get my flying gloves oily. By the way, in the engine weigh comparisons, is the weight of the oil tank (and oil) needed on the radial factored in? +++ #11565 From: Budd Davisson Subject: Re: Radial Engine operations Once you've flown one of these things for 20 hours, you'll never want to go back to a square motor. Also, you just can't get the kind of thrust with a flat motor. Still a 540 is a better bet for nearly everyone. As for the oil/intake thing: the article didn't take into account enough of the work done by the Kimballs's when putting the kits together for the Model 12 Pitts. With the scavenge pumps and oil shut offs, the possibility of hydraulicing a cylinder is much less than it is even with an R-985. The starting system is the same way. Lots of new, super simple fixes. As for starting: you could ignore the pneumatic system if you wanted (although it works great) because it's the easiest propping engine ever invented. It's geared just enough that you can "walk" a blade through and start it. As for oil/oil tank, you carry 8 quarts more and the tank is ten pounds and that weight isn't included any more than than oil is figured in Lycoming weights. Bob and I have been talking, now that I have accurate FWF weights for everything, and the total weight increase is about 100-135 pounds depending on which 540 you compare it to. 60 pounds of that can be located in the baggage compartment for Cg control. The flat nose, 220 hp engines don't appear to be worth the effort because they are only 37 pounds lighter than the normal 360 hp M-14P. bd +++ #11640 From: Budd Davisson Subject: Re: engines. re: Deal on engines, etc. There ain't no such thing as "deal" when it comes to engines. We've had the OEM prices from them for some time and they are too embarrassing to want to forward. A new 540 is well over $30K OUR cost and we'll be asking $31,995. We're getting the same deal as Van's or anyone else, so everyone is stuck in the same price range. 180's are around $24K, as I remember. I've forgotten the prices on props, but they aren't quite as out rageous. Mazdas and Fords are looking mighty good. So are M-14Ps I wonder how much Pirelli it takes to get a BH in the air? bd +++ #11644 From: "Bruce A. Frank" Subject: Re: Re: Tables & Sheesh! And engines. > I think I will look into a chevy 350 v8. 300 hp @ 4200 rpm. Belt > Drive electric variable prop, should weight just under 500lb. Try contacting Johnny, the owner, at Noethwest Aero Johnny He was putting out an LT-1 300+ hp and included the PSRU for $14,000. I don't know what the status is right now. For some reason I cannot pull up the home page of the web site tonight, but can reach some of the related pages. Maybe it will work later. Here is the site address http://www.northwest-aero.com Bruce A. Frank +++ #11649 From: "Bruce A. Frank" Subject: Auto engines Not having all that info in one place on the conversion is a problem with the Chevy, but I have seen conversion information manuals advertised in the classifieds in "Kitplanes" and "Sport Aviation". A rule of thumb is that you want to run these engines in the parameters of their manufactured capabilities. You can push the 4.3L Chevy V-6 to 300 hp, but who knows how long it will last. The engine is fully capable of running at 230-240 hp forever. Typical mods are going to be a cam change, not too radical, but one that allows the engine to breath well; a piston change if you're not getting near a 9:1 compression ratio or there have been shown to be problems with the stock pistons; a manifold change or porting job if there has been show in racing use that the stock manifold does not breath adequately; and one last thing is the carb or fuel injection system...most, not all, auto conversions are kept simple. Carbs are dirt simple. Electronically controlled injection systems add about 10% to the power, but complicate the installation because of the need for a back up control system. Again I am going to point people to Northwest Aero's web site. Johnny Lindgren has gone to the trouble to create pages outlining the conversion process for several engines. http://www.northwest-aero.com Now if you want to go with the Ford, that is a different story. All the mods, idiosyncrasies, fixes and parts lists are covered pretty well the Blanton original builders manual and my newsletter. Oh, one last thing about the Ford power, certainly the 3.8L V-6 can be pushed and the 4.2L V-6 offers potential for normal operating power right up there with the Chevy 4.3L, but we have several builders with 1500 to 2000 hours at the Ford recommended power maximum output of around 200-210 hp with only a piston change, cam grind and a carb installed. The object with longevity in an auto-conversion is to run it near stock as possible while producing the power needed. Jerry Schweitzer is running a stock Ford 4.2L V-6 (Ellison Throttle Body for his carb) producing 210 hp in his RV-6. He gives up a little weight, but he has produced rock solid durability with a very inexpensive installation (well, except for that pricey Ellison). Bruce A. Frank +++ #11650 From: "Bruce A. Frank" Subject: Engines. This may be a good selection. I don't know this particular engine but sometimes DOHC engines end up being a bit wide for the cowling. Not an insurmountable problem, but a bit more effort required to make things fit. Any time you have a fuel system controlled by a computer you need to have two on board for redundancy. However well they work in the car, you still need the back up. Salvage yard can save a lot of money on that along with the wiring harness. Bruce A. Frank +++ #11651 From: "Bruce A. Frank" Subject: Re: Auto engines I made a mistake last night. I said that Northwest Aero offers the LT-1 Corvette engine as an aero-conversion when it is the LS-1. (Aluminum block 350CID V-8) http://www.northwest-aero.com Bruce A. Frank +++ #11652 From: "jrm_nh" Subject: Re: Auto engines Just look at the bare ls-1. It's a beauty. Where else can you get 320 hp for $6500 bucks. It should run forever @ 4000 rpm at about 260 hp https://www.spoperformanceparts.com/store/catalog/Product.jhtml? PRODID=1108&CATID=1099 +++ #11653 From: Alan Nauman Subject: Re: Auto engines I think Northwest aero was sold and they don't sell the engines any more. I thought the LS-1 would be pretty cool, but it is a little on the heavy side. I like the idea of an auto conversion that is kept simple. The weak point I see in the sube conversions is that people typically use the FI and computer. There are just too many items that are tricked in the automotive computer. I just don't like shorting pins and such on the computer to to get the thing to run. I want to stick to something I can put a carb on and still get enough power. Has anyone thought about using Holly Pro-jection? That uses a stand alone computer and you are supposed to be able to manually adjust the mixture from inside. I have thought that it could provide FI (throttle body) while keeping the computer part relatively simple. Thoughts? Alan Nauman +++ #11662 From: charles.k.scott@d... Subject: Re: Digest Number 921 > While I haven't started on my bearhawk yet (well, I'm making the gas > caps as shown in the newsletter!), I've given a lot of thought about > engines. Its more than likely that I'll go with an auto engine > conversion, although I'm not sure which one. The Chevy 4.3l (v6) > that was in "Custom Planes" last year looks good, and a larger V8 > would be an option too. The big problem, as I see it, is the fact > that there doesn't seem to be a collected source of "what to do and > what to get". You will want to replace a lot of stock parts to > withstand the higher RPM's of peak horsepower, and the torque of the > prop. So where does one find all this stuff? I've seen some 4.3l > engines go on Ebay pretty cheap, around $1K or less. Historically John finding the collected source has been the problem. Other than Bruce's ongoing Newsletter focused on the Ford 3.8 and now the 4.2, there really isn't any other such collection of information. The Chevy 4.3 is not a bad choice but has it's negative factors. It's heavy. Everything is cast iron on it including the heads and intake manifold and timing cover. This makes it nicely stiff and resistant to overheating damage but pretty heavy. Typically builders using this engine have bought aftermarket aluminum heads from racing sources. But this too is a compromise in that the latest, most available heads have monster valves which are great for racing but are overkill for our use. It actually flows too well for the rpm range in which it is used. The earlier aluminum racing heads had smaller valves and they worked better for our purposes. You can get decent intake manifolds for it though, from Edelbrock. You can't do that with the Ford, there just isn't anything out there, the engine isn't raced. But the neat thing about the Chevy is that you can buy a Marine version of it for under $3,000 and that is pretty much everything but the induction unit and starter. The Marine version is heavy duty and already has the cam you want. Several people have gone this way. When I say buy, I mean brand new. I went the opposite direction, I found out about an engine seller who had any number of Fords I could want, just wanted to know where to send them. He wanted $150 each. I bought two. The modifications needed for this engine are many, and I'm doing them all and including a few that aren't part of the usual package. For instance I bought aftermarket studs to attach the cylinderheads and bearing caps. These things are what the big shot racing teams use and since the Ford has a history of cylinderhead gasket leakage, I thought it was prudent to get the best clamping devices money could buy. On the other hand, there is confusing advice about the valve springs. For sure I don't want to re-use the originals, who knows how many miles of operation they've seen. But on the other hand, there doesn't seem to be much need for special high strength racing springs either since the rpms never exceed 4,800. Valve springs have one job only: They are supposed to keep the valve pushed against the lifter via the pushrod and seated when not being lifted (ok two jobs). As rpms rise, valves with weak springs can loose contact with the lifter and "float" to the point where the cam lobe has passed by and the valve is supposed to be seated but it isn't, it's still floating and coming back down. This allows backfiring through the intake manifold. So the valvespring only needs to be strong enough to keep it pressed against the camshaft lobe at all ranges of rpm. Anything more is overkill. I've discussed this with the owner of the machine shop where the block is getting it's boring and honing done and the guy is in agreement that stock spring would be fine, given the limited rpm range. But they must be NEW, not used. So I'll be contacting the local Ford dealership shortly. Building an engine is paying attention to lots and lots of details. The more details you mind, the smoother and more powerful the engine runs, up to a point. So things like valve guide clearance, I'm leaving up the guy who does this sort of thing all the time. Another thing I learned when making a living as an auto mechanic is that if you replace the valve guides, the valves very likely will not sit on the seats exactly like they did before, so you either have to spend a long time lapping them in or the seats have to be reground. Sorry, looks like I lapped on a bit too long myself. Corky Scott +++ #11663 From: John Mireley Subject: Re: Digest Number 921 > But the neat thing about the Chevy is that you can buy a Marine > version of it for under $3,000 and that is pretty much everything > but the induction unit and starter. The Marine version is heavy > duty and already has the cam you want. Several people have gone > this way. When I say buy, I mean brand new. Are these "Marine version" engines availabel as crate engines from GM or are they custom built by the boat builders? John Mireley +++ #11664 From: "Bruce A. Frank" Subject: Re: Digest Number 921 > Are these "Marine version" engines availabel as crate engines from > GM or are they custom built by the boat builders? They are available from GM ready to run in boats. As Corky says, except for the weight penalty, which isn't that bad, they are virtually ready to run...add one PSRU. Bruce A. Frank +++ #11665 From: Budd Davisson Subject: Re: Digest Number 921 What's the ready to run weight of the Chevy, including water/radiator/PSRU and which PSRU for that engine has the most time on it? I like the idea of a stock Chevy marine engine if the weight isn't too much. I don't like the idea of modifying engines. In the history of automotive conversions the problems always seem to be with the engine, not the reduction unit, so the optimum system would be one that uses an engine from the factory that benefits from all of their testing and know-how coupled with a decent reduction unit. If you want to start a verbal free-for-all, ask any of the following questions: -what's the best fabric covering system? -what needs to be done to an auto engine to make it flyable? -how do you feel about gun control/abortion/religion? Everyone has their own ideas. In the case of the auto engines, however, the factory has invested millions and millions of dollars to produce a well tested product and if they have one that is close to what we need for our use, that's what we should be using rather than hot-rodding them because we don't have the ability to adequately test them before putting them in the air. bd +++ #11666 From: Chris Hoppe Subject: Re: Digest Number 921 How about industrial versions of Chevy engines? My boat has a Chevy industrial engine (that's what it indicates in the NAPA parts catalogs) coupled with an OMC exhaust/cooling system. As I understand it, the primary difference is the heavier crank, bearings, and cam. Supposedly the marine and industrial engines are optimized for continuous high RPM and load. Is this true? Chris Hoppe +++ #11667 From: John Mireley Subject: Re: Digest Number 921 > Are these "Marine version" engines available as crate engines... These engines are referenced as "Marine Base" engines if any are searching the web for suppliers. I've not seen any with aluminum heads or blocks. Is there a reason for this? You would think that racing boats would be considering the weight. John Mireley +++ #11670 From: "Bruce A. Frank" Subject: Auto-Engine Conversions (was: Digest Number 921) The Chevy engines are most widely use with Belted Air Power's cog belt PSRU and Northwest Aero's cog belt PSRU. I do not know the weight of the Chevy setup, but I do know that replacing the cast iron heads and intake manifold with after market aluminum units saves approximately 45 lbs. As for "Hot Rodding" the automotive conversion, our goal is longevity. At least in the case of the Ford conversion, we are not extracting more power than the factory has in certain applications(Over the years I have been able to submit questions to one of the engineers who helped develop the 3.8L V-6 to find out if we were expecting too much from this engine). The 3.8L as produced by the factory for the Windstar develops 210 hp. As modified by the Blanton manual the aero conversion of the 3.8 is a 195 to 210 hp engine. The hp rating is still at the factory specified 4800 rpm; though we switch to Wiseco pistons the compression ration stays the same; and the recommended cam change is not radical providing normal idle down to 600 rpm. Most automotive engines these days are set up to reach peak torque at the rpm used to drive the car around town...about 2200 to 2800 rpm. The cam change moves the peak torque from that low range into the range at which most builders will cruise the engine. In the case of the Ford that is around 4000 to 4100 rpm. We have several engines which have now exceeded 1500 hours and Ken Mitchell, Bountiful, Utah, decided to do an overhaul at 2000 because he needed to refurbish the BD-4 fuselage. The engine at 2000 hours still showed compression within 6 psi of that when the engine was first broken in. Most of us think that a pretty good track record and an indication that the recommended mods have not impacted durability. Bruce A. Frank +++ #11671 From: "Bruce A. Frank" Subject: Re: Digest Number 921 > Supposedly the marine and industrial engines are optimized for > continuous high RPM and load. Is this true? Yes, that is true. Bruce A. Frank +++ #11675 From: Budd Davisson Subject: Re: Auto-Engine Conversions (was: Digest Number 921) The track record of most of the "Blanton" conversions speaks for itself. Now we need something of the same type in the 250 hp, bigger displacement range to swing a bigger prop. What is anyone doing for constant speed/variable pitch props on the reduction units? bd +++ #11676 From: "Bruce A. Frank" Subject: Re: Auto-Engine Conversions (was: Digest Number 921) Northwest Aero's PSRU is set up so that it could be adapted to a standard CS prop. I do not know if anyone has done it yet. Right now, if you have a LOT of money the MT electric is all I know about for the higher HP. Ivo Prop's cockpit adjustable can be had with an electric controller that makes it CS. Warp Drive keeps leading me on with promises of a CAP or as CS in the future. NSI uses the Warp blades in an electric CAP but is limited to 160 HP. Bruce A. Frank +++ #11678 From: "jrm_nh" Subject: Re: Auto-Engine Conversions (was: Digest Number 921) > Do you have a URL for Northwest Aero? I'd like to see if they have > an accurate weight figured out. Check the 350 V8 Chev in the Engine Recipes Section I think I read 500lb complete http://northwest-aero.com/ +++ #11681 From: "Dave Roberts" Subject: Re: Auto-Engine Conversions (was: Digest Number 921) Check out Team-38's web site. Their marathon 350 weighs 460lbs. I would guess this would be close to the weight of any V8 small block Chevy with the aluminum heads and intake. Jess Myers[Belted Airpower] said his PSRU weighs 38lbs and is 12" front to back. I think a small block V-8 is approximately 24" front to back depending on the water pump. I may need to be corrected on that. It is about 24" from the pan to the top of the air filter. Again this is approximate. I measured Bob's BH at Oshkosh. As near as I can tell it is approximately 36" firewall to prop hub. The V-8 will stick out a little further when you leave a little room between the engine and firewall. The biggest problem that I see is depth and weight. Maybe somebody that is more of an engineer than I am can figure the engine installation out. The extent of my engineering ability is the TLAR method and a lot of head scratching. Dave Roberts Bob told me that Proto II firewall forward weighs in at approx 450lbs. +++ #11684 From: "Bruce A. Frank" Subject: Re: Re: Auto-Engine Conversions (was: Digest Number 921) You may also find that the CG of the V-8 and PSRU will be closer to the firewall than that of an 0-540. Bruce A. Frank +++ #11685 From: Budd Davisson Subject: Re: Re: Auto-Engine Conversions (was: Digest Number921) CG of a 540 FWF is about 22 " from the firewall. +++ #11686 From: "Bruce A. Frank" Subject: Re: Re: Auto-Engine Conversions (was: Digest Number921) I don't know where the CG of, say, the LS-1 with PSRU falls. Maybe Johnny at NWA can tell you. The Ford V-6 with PSRU has a CG that is 5 inches closer to the firewall than the 0-360 Lycoming. This made the difference in not having to place any tail ballast in the V-6 STOL. The battery is moved to aft of the luggage ba, but that is all that is necessary. First thoughts were that the V-6 STOL would need 20 lbs of lead in the tail. You know, it is possible that Johnny could/would supply package auto conversion deals for the kitted Bearhawk! Bruce A. Frank +++ #11687 From: charles.k.scott@d... Subject: Re: Digest Number 922 This would be achieved using the Geschweiger conversion. The engine is a big block Ford with a HyVo chain PSRU developed by the now deceased Ron Geschweiger. I spoke with him a year or so before he died and talked with him about the conversion. I was thinking of using it for my Christavia but he explained that it's really designed for bigger engines and would be overkill for the 3.8L V-6. Also, Northwest Aero was making firewall forward packages based on the Corvette engine. Tough business to be in (building auto conversions) as the market is small and the scepticism big. Corky Scott +++ #11688 From: charles.k.scott@d... Subject: Re: Digest Number 922 > The track record of most of the "Blanton" conversions speaks for > itself. Now we need something of the same type in the 250 hp, bigger > displacement range to swing a bigger prop. An additional datapoint: I contacted one of the vendors for the Warpdrive prop and discussed the rpm range and power my engine will be making. Being conservative I'm estimating 180 hp but I know the engine will be spinning at 4800 rpm when that's happening. With a 2 to 1 reduction ratio, the prop would be turning at 2400 rpm. The recommended prop under these circumstances turned out to be the 74" prop with FOUR blades. I'm assuming that's because the 2,000 rpm at cruise is lower than the typical standard type prop so it needs more blades to absorb the thrust. Or they could be just trying to make money since this is the most expensiver version of the prop... Corky Scott +++ #11689 From: Budd Davisson Subject: Re: Chevy 350 weight It clearly says 575 pounds, doesn't say anything about whether that includes coolant or radiator, which I'd be surprised if it does. Does not include prop. Estimate 650 pounds engine/prop, plus mount, oil radiator, cowl, etc. other miscellaneous so total FWF is probably around 700 pounds. The airplane won't safely carry that amount of FWF load without some tubing increases plus it'll take some weight in the tail. I've e-mailed them asking for total weights but no answer yet. bd +++ #11693 From: "Bruce A. Frank" Subject: Re: Re: Auto-Engine Conversions (was: DigestNumber921) FWF with the radiator (aluminum) in the engine compartment and the McCauley 8467 (metal), the only one I have seen on scales ran 467 lbs including water and oil with the Blanton PSRU (30 lbs heavier than the NWA unit). Bruce A. Frank +++ #11694 From: John Thompson Subject: Chevy Engines I need to find that article in Custom Planes about that guy who used a 4.3l chevy in his amphib. As memory serves, he spent about $15,000 for a 250hp rated engine. He replaced the cams, crank, pistons, heads (I think), con rods, and several other pieces. He had all his work done by a shop. Like folks have mentioned, its hard to get collected information. But its my understanding that in general, crankshaft and camshafts need to be replaced because of the higher loads imposed by the longer high RPM runs, possibly the heads for wieght. Other stuff like pistons can be replaced for either performance or wieght reasons. This is especially true if you go for higher HP figures. we definitely need more collected information on chevy auto engine conversions John +++ #11696 From: Ken Beanlands Subject: Re: Chevy Engines At prices like these, it certainly makes the "build-your-own" IO-360 very appealing.... Ken Beanlands B.Eng (Aerospace) +++ #11696 From: mprather@s... Subject: Re: Chevy Engines That seems like an outrageous amount of money for a car engine. Part of the motivation for using converted engines is being able to run down to NAPA and by a rocker arm, pushrod, timing gear or whatever. If you are running exotic stuff that only comes from Summit or someone more esoteric, it is indeed hard to see the advantages. I'll bet he is running Al block and heads. The 4.3 is not cheap to make light. Al 350 parts are often cheaper. On the flip side, I'll bet his "250hp" engine can probably be run 2500 hours between rebuilds. Additionally, its probably nice to be able to run along flat out at cruise alt, decide you want to land at the field 5000' below, and just chop the power and point the nose down to get there. No shock cooling, and good, safe cabin heat. I recently saw something on aero-news that said that one of the scaled mustang outfits was happy about a new engine they had put together. It replaces the Chevy 502 that their customers apparently had problems with. It seems that there have been top-end oiling difficulties on the 502 when installed in airplanes. I wonder if the small blocks and similar 4.3's are subject to the same isssues. Matt Prather +++ #11698 From: "zipppydoggg" Subject: Re: Radial Engine operations I checked out the MP14 as installed in the Pitts per your hint, very interesting. I feel myself being swept into the MP14 camp. It looks like the price could be competitive, depending on prop selected. Just curiosity, what comprises the 60 pounds that can be located in the baggage compartment? Would you expect that more than the standard gas tankage (with or without aux tanks) would be desired with the MP14 (building my wings now)? Would one have to shave after each flight, the testostrone would be dripping out of the tail pipe on shutdown, after all? :-> Rob "cold war enemy, now a (potential)customer of the Ruskeys" Gaddy +++ #11698 From: John Mireley Subject: Re: Chevy Engines A ZZ4 crate engine (350 HP) new from the factory is $4000 http://www.high-performance-engines.com/ce03.html A LS1 aluminum block engine (320 HP) is $6200. http://www.high-performance-engines.com/ce10.html. A Marine Base engine (290 HP rebuilt) is $1900 http://www.high-performance-engines.com/vm08.html +++ #11701 From: mprather@s... Subject: Re: Chevy Engines There is a dealer in OR that has a little better deal on the LS1. See Sallee: http://www.sallee-chevrolet.com/sales.html and follow the link on the right. They offer the LS1 for $5400. Matt- +++ #11702 From: John Mireley Subject: Re: Chevy Engines I looked into Sallee's LS1 awhile back myself. They say the crate engine weighs in at 390 lbs. Would this allow enough to get FWF weight into range for the Bearhawk? If it is, it would sure be a tempting solution. BTW, the LS1 is rated 345 HP at the rear axle on the Corvette. The fellow at Sallee thought it would come in around 400 HP at the drive shaft @ 5800 RPM. Just to weigh the apples with the apples. Thanks to whomever posted the suggestion about the Olds 3.5L aluminum V6. I've been wanting to get more info about that engine ever since test-driving a 2000 Intrigue. (Sure "flew" better than my 4-banger Ford Contour!) Shawn Harrison +++ #11705 From: "Daniel Fox" Subject: Re: Chevy Engines > I recently saw something on aero-news that said that one of the > scaled mustang outfits was happy about a new engine they had put > together. It replaces the Chevy 502 that their customers apparently > had problems with. It seems that there have been top-end oiling > difficulties on the 502 when installed in airplanes. I wonder if > the small blocks and similar 4.3's are subject to the same isssues. I'd have to wonder whether the customers at "one of the scaled mustang outfits" were in the habit of getting upside down and/or boring twisty holes in the sky, also. Stock auto engines don't take that into account. --dan fox +++ #11705 From: "Bruce A. Frank" Subject: Re: Chevy Engines > I'd have to wonder whether the customers at "one of the scaled > mustang outfits" were in the habit of getting upside down and/or > boring twisty holes in the sky Several Ford V-6s have been used in aerobatic planes. The same modifications have to be made to aerobatic automotive engines as have to be made to aerobatic aviation engines; oil systems and fuel systems. Other than that they handle it just fine. Engines with design problems are engines with design problems whether in cars or airplanes. Bruce A. Frank +++ #11708 From: "Bruce A. Frank" Subject: Re: Chevy Engines > What's the current info on the Rover (ex-Buick) aluminum V-8? At 300 > c.i. it has promise. The Ford 3.8L V-6 is lighter and produces more horse power. Bruce A. Frank +++ #11709 From: Budd Davisson Subject: Re: Chevy Engines How much HP are we talking about and how much torque on how much prop? bd +++ #11710 From: Budd Davisson Subject: Re: Chevy Engines Actually, I meant to ask for the thrust, not the torque. bd +++ #11711 From: "Tony Chisum" Subject: Engine With all this engine I have not seen anything about the Jabiru 6000. It is 8cyl. 200hp. 231lbs. and comes with all accessories for $15,600.00 Here is the web site. http://www.usjabiru.com/jabiru_6000.htm Would this not be a good engine for the Bearhawk? Tony +++ #11712 From: "Tony Snow" Subject: Re: Tables & Sheesh! And engines. Bruce, I don't really qualify according to your question, but... I will build an aircraft someday, maybe a BH, maybe something else. But I will build. And I will power it with a Mazda 13B conversion. I will also use the redrive system and engine computer manufactured by Tracy Cook (Real World Solutions, Inc.)at: http://www.rotaryaviation.com I will probably swing a Warp Drive ground adjustable two bladed prop. The reasons are simple, really simple. Only three moving parts in the engine. Simple right? Major considerations for this conversion are cooling (both oil and water) and exhaust temperatures. Many of these engines are in the flying or advanced development stage nearly ready to fly. One of the greatest proponents of this engine conversion from an engineering perspective is Paul Lamar. He runs the AirCraft Rotary Engine (ACRE) Newsletter. His site (with major archives) is located at: http://home.earthlink.net/~rotaryeng/ACRE.html Both of these guys, Paul and Tracy, are great people. I've met them both and had the chance to talk at length. They are the two most qualified leaders of the Mazda 13B conversion group. As a side note they call themselves "Rotorheads" and even had Felix Wankel t-shirts printed up for Oshkosh. There are several consideration in rebuilding the 13B as an aircraft powerplant, but with a manufacturer quality rebuild: using a different O ring set, vibration isolation, oil flow mods, but they are minor. All up cost (my estimate not theirs): $6,000 plus prop. This gets you a rebuilt 1989 13B, turbocharged producing about 220 - 230 hp, electronic EFI computer programmed for aircraft application, redrive, and cooling parts. I am convinced about the engine. I've got a 1988 convertible RX-7. Sorry to be long winded. Tony (still waiting) Snow +++ #11713 From: Budd Davisson Subject: Re: Engine Yes, it might be a good engine but at $15K you're better off buying a proven, overhauled aircraft engine. bd +++ #11714 From: mprather@s... Subject: Re: Engine Does anyone have a comment on using a fixed pitch prop in the Bearhawk? Many of the auto conversions, along with the Jabiru appear to only support fixed pitch. Seems like kind of a bummer to give up all of that extra performance that a constant speed prop makes possible. Is the 180hp prototype constant speed? Matt- +++ #11716 From: Budd Davisson Subject: Re: Engine Yes, the 180 Prototype is constant speed but that's not a necessity. Bob Marek has a fixed pitch on his 160 powered BH. Yes the fixed pitch has to be a compromise but it's one just about anyone could live with. bd +++ #11717 From: Budd Davisson Subject: Re: Tables & Sheesh! And engines. > I will build an aircraft someday, maybe a BH, maybe something else. > But I will build. And I will power it with a Mazda 13B conversion. What is the upper horsepower limits of existing, normally aspirated rotaries? bd +++ #11718 From: John Dougherty Subject: Re: Tables & Sheesh! And engines. My 20B 3 rotor is supposed to be about 275 normally asperated and 375+ when turboed......Jack +++ #11720 From: "Bruce A. Frank" Subject: Re: Chevy Engines > How much HP are we talking about and how much torque on how much > prop? 200 hp at 4800rpm about 220 ft-lbs. At about 4000 rpm (Typical cruise with a 2:1 PSRU) it makes about 175 hp at 227 ft-lbs. Bruce A. Frank +++ #11721 From: "Bruce A. Frank" Subject: Re: Chevy Engines I should have read the next post before I answered the first. Thrust strictly depends on the prop choice. The original recommended McCauley 8467 pulled the plane along at about 125-130 mph at 4100 rpm. Most builders who stuck with the McCauley two blade had it repitched to 72 or 76 inches for a bit faster cruise. Bruce A. Frank +++ #11722 From: Budd Davisson Subject: Re: AviPro Engine/Prop Prices Enough of you have asked that we'll go ahead and post the prices for new Lycomings and Hartzell props. We aren't offering Continentals yet. New Engines/Props available O-540 A4D5, 250 HP at 2575 RPM. $31.995 This model comes with two sixth order counterweights for use with the Hartzell "compact" series prop. Comes with: Skytech lightweight starter, alternator, two new mags, new carb, & engine driven fuel pump (which Bob says it doesn't need). O-360 A1A, 180 hp, similarly equipped. $22,400. Now for props: Prop For 0-540 Hartzell CS 84" 2 blade model(compact series) for O-540 #C2R00070 HC-C2YR-1RF/F8477/SM19 . $5,400. Spinner assembly for this prop is $695. Hartzell governor $2,025 Prop for O-360 (includes a dampener, $1,015 alone). A C3R00053 HC-C2YR-1BF/F8477-4/SM16 . $6195. Spinner and governors fit both O-540's and O-360's. Three blade props are available, but weigh 20 lbs. more than 2-blades. Terms are 35% down at time of order, 65% due one week before ship date (usually about 90 days after order is placed). Transportation and insurance are provided by buyer. +++ #11726 From: "rodsmith52" Subject: Re: AviPro Engine/Prop Prices Well at least thats a pretty decent price for a new Hartzell for the 0-540. I hesitate to ask, but how much for the 3-blade? If I had $32000 to spend for an engine I would be buying one of Monty Barrett's set up for about 290hp and a much better chance of being a reliable engine than a new Lycoming. I think $14000 for a 360hp M14P sounds like a much better deal. I could have that plus a 3-blade MT prop for it for $25000 and $12000 left over versus a Lycoming/Hartzell combination. Desert Hawk - YES! Hey, I live in the desert now. Rod Smith #246 +++ #11728 From: Bob Romanko Subject: RE: Tables & Sheesh! And engines. > What is the upper horsepower limits of existing, normally aspirated > rotaries? I hear 180 thrown around a lot for the 13B. Planter Bob +++ #11729 From: "rodsmith52" Subject: Re: Tables & Sheesh! And engines. Has anyone checked out Power Sport Aviations rotary. Looks like they have done a lot of engineering and testing on their 215hp 2 rotor normally aspirated engine. Too bad they are using Lycomings price sheet. I might think about having someone build me a 3 rotor engine and using Power Sports reduction unit which they claim is good for 300 some horsepower. Sounds like it has been well tested. At the present time though you would be limited to a fixed pitch or MT electric CS prop. What have any of you heard about the electric CS props? I've heard they are pretty slow to respond compared to a hydraulic prop. Rod Smith #246 +++ #11730 From: "rodsmith52" Subject: One more auto conversion post Who started this anyways? If I thought I could be happy with a 165hp Bearhawk I would strongly consider Jan Eggenfellners Subaru firewall forward conversion(www.subaruaircraft.com) He is making considerable inroads into the RV and Glastar engine market. Everything I have read on them seems to be positive. I believe he is having some success because he is using an essentially stock engine and not asking for outrageous amounts of HP from it. I talked with him several months ago and he is considering a 6 cyl subaru conversion that would be in a HP range that I am interested in. Right now he seems to have his hands full getting engines built. He also has a supercharger in the testing phase for his engine. It is setup to maintain HP at altitude, not increase HP at sea level. Rod Smith #246 +++ #11731 From: charles.k.scott@d... Subject: Re: Digest Number 924 > All up cost (my estimate not theirs): $6,000 plus prop. This gets > you a rebuilt 1989 13B, turbocharged producing about 220 - 230 hp, > electronic EFI computer programmed for aircraft application, > redrive, and cooling parts. > > I am convinced about the engine. I've got a 1988 convertible RX-7. I had a 13B in my shop for a while and ended up selling it when I added up the positives against the negatives. One of the things glossed over by proponents of the Mazda rotory is that it requires oil to be injected down the throat of the fuel induction device in order to lubricate the tip seals of the rotor. Most performance builders of the engine remove the oil injection unit and chuck it as being unreliable for the sustained high rpm operations necessary for flight or racing. This means you must mix oil with the gas every time you fill up. I pictured myself refueling the wing tanks, standing on the ladder and then attempting to calculate how much of this special oil that I would have to carry around with me to pour into the tank in order to get the proper ratio. That was that straw that broke the camels back. I put the engine up for sale the following day. These engines may have few moving parts but that doesn't mean they are easy to rebuild. In fact one company that sold them along with their PSRU literally begged me not to attempt to do it myself claiming I would never be able to get it back together again correctly. Being an auto mechanic at the time, I didn't listen and took it apart anyway because something in the combustion chamber was causing the engine to seize. That turned out to be a huge piece of carbon. I did manage to get the engine back together again with new seals, except for the tip seals which I retained (because they seemed ok and also because they were incredibly expensive), but everything about assembling it was fiendishly complicated and I appreciated what those guys were talking about. Corky Scott +++ #11732 From: charles.k.scott@d... Subject: Re: Digest Number 925 > 200 hp at 4800rpm about 220 ft-lbs. At about 4000 rpm (Typical > cruise with a 2:1 PSRU) it makes about 175 hp at 227 ft-lbs. Not to forget, reduction units are torque multipliers. Any time you gear down an engine, the torque is multiplied by the ratio of the gearing. In this case it's a 2 to 1 reduction ratio, it multiplies the torque by a factor of 2 so the prop sees 440 lbs of torque, not 220. Corky Scott +++ #11733 From: charles.k.scott@d... Subject: Re: Digest Number 925 > Now, about those Ford V-6s.... ;-> Cost would depend entirely on the resources of the builder and his talent for building engines. There is really a lot to successfully putting together an auto engine and making it something capable of flight adds to the check list. All this information is out there in one form or another but it IS a lot to digest. You can buy the blocks for as little as $150. These are complete engines. Like I said previously, at that price I bought two, just in case I found problems with parts. Neither crank was in bad shape, but one miked up slightly less worn than the other so I'm using that one. Things to pay extreme attention to: Connecting rods - these should be inspected, magnafluxed and probably shot peened. Connecting rod bolts - junk the used ones, they've served their life and deserve to be retired. They stretch when installed first and you can't re-use them, especially if they've been in the engine for 10 years. Pistons - use the ones that have been establised as successfully running in this engine in it's aero form. They bump the compression ratio up to 9 - 1. Camshaft - This is one of the several areas where Blanton had the proper development done. The specs for this camshaft have been reviewed at least several times by camshaft professionals and no one has found any reason to change the specs. It does what it's supposed to do; move the torque up into the 3800 to 4300 rpm range where we need it to be. There are many modifications necessary for the intake manifold as it was one of five tried by Ford during development and the one selected flows well at low rpms but strangles above 3500 or so. Plus, the engines sat in the pickup bodies slanted down to the rear, so the mating surface for the TBI was tipped up to level keep it level in the car. Since we turn the engine around and it's level, the float chamber is close to being out of spec when you nose down for descent. So the mating surface gets planed down (I really got a kick out of doing that but it does require access to a machine shop). There are several ways to modify the chamber below the carburator to improve flow, but basically you machine down the wall that seperates the two chambers to form a mini plenum chamber. Then you can also space the carburator up away from the intake manifold to allow the mixture more time to vaporize before it routes to the various combustion chambers. Being a single plane manifold, it never will flow very well, but it will flow adaquately enough for anyone who uses the proper pistons and camshaft to see between 180 and 200 horsepower. One builder went with higher compression pistons, spent a lot of money with a manifold expert (who applied various black magic fixes) and spun the engine bravely to 5300 rpm and saw 235 horsepower. He's the only person I'm aware of who is attempting to routinely get that kind of power. On the other hand, several who made minimal modifications to the intake manifold got 180 horsepower at 4800 rpm. Some guys are trying to adapt the Ford multipoint fuel injection system using the latest 4.2. I wish them luck. I prefer the simplicity of the carburator; it doesn't require electricity or computer chips to run. As to the ignition, I bought a distributer from Northwest Aero that they had machined for the engine. I has two magnetic pickups in it, their output will be routed to an MSD (I think that's the name, I haven't bought it yet) switcher. This is the type of setup you see on Nascar racers. There are two coils and the switcher automatically switches from one coil to the other in case of failure. The object is for this to happen automatically so that you don't have to troubleshoot if the engine suddenly fails on takeoff. My recollection is that the distributer cost $85. I also bought a tiny alternator from NW Aero and the bracket for it. The alternator puts out 35 amps. If all goes well, the engine will be assembled this winter in my shop that now has an overly large propane furnace instead of my dinky little propane heater. It will take about 5 minutes to come to heat instead of about two hours. An important consideration during the long New England winters. There's lots more to the engine, it would almost take a boring book to go over everything. One thing I haven't mentioned is my desire to use the exhaust to augment to cooling flow through the radiator, and to incorporate an effective muffler. We'll see if that is possible. I sort of have to hang the engine and begin putting things on it in order to see how everything will go. Corky Scott +++ #11734 From: "Bruce A. Frank" Subject: Re: Digest Number 925 Corky is correct. I was looking at the Dyno charts where the engine is hooked directly to the dynamometer. In application, with a 2:1 PSRU, half the rpm and double the torque (he says as he slaps his forehead with the palm of his hand) Bruce A. Frank +++ #11735 From: Tony Dean Subject: Re: Auto engines Some years ago Paulk Lamar was a strong detractor of auto conversions. After a long discussion on R.A.H. he posted (from NTSB sources) a distillation of engine problems across experimental aircraft and the actuall breakout of problems was counter to his arguments. He argued that auto engines were not adequately engineered for aviation duty cycles and that the number of engine releated failures in experimental aircraft proved it. Unfortunately, for his argument, the actual number of catastrophic engine failures was rather low. There was, however, a disportionately high number of fuel, installation,and some cooling failures. This is probably more due to lack of standardized FWF configurations than anything. Richard Finch recommends that for an auto conversion that you copy something that works and not get too creative on the installation. Regards Tony Dean PS. Paul seems to advocate the Mazda rotary these days. +++ #11736 From: Ken Beanlands Subject: Re: Re: AviPro Engine/Prop Prices How about the new IO-390 (bored out IO-360, 210 hp, 4-banger)? Ken Beanlands B.Eng (Aerospace) +++ #11737 From: "teyeomans" Subject: Tom Yeomans ford update. I have been doing a lot of things to the engine and have had it grounded for about 2 months. I have it in the air now and the systems are working nicely. ( about 4 hrs) I was originally having major cooling problems. At this time I have a very dirty front end but cooling is solid at 196 degrees. The radiator is outside the cowling at this time. The one thing that seemed to make a difference is I dropped the front of the radiator 1 inch. I just set up some temp gages to measure the temp drop across the rad. I hope to find some smaller ones I can put in the front of the cowl as the subie guys are doing. But for now I will just fly slower. At this time I am running a warp drive prop set to 11 degrees pitch. That will give me 5400 rpm max. I am indicating 90 mph at 5000 rpms. I am running an aftermarket fuel and ignition computer that is indicating a perfect fuel burn. Haven't really done a lot with the fuel calculations yet. The computer calculates about 8 gph but I haven't seen that much in the air .. Looks like around 5ghp. I know I am not getting the HP I had hoped for but I will work on that after the cowl/radiator gets some work. I need to remember I am taking of at 6600 ft. Tom Yeomans +++ #11738 From: "Daniel Fox" Subject: Re: One more auto conversion post Rod, do you know what 6-cyl engine Eggenfellner is planning to base the conversion on? I followed the online Soob groups for a long time, and eventually gave up on the idea for a Bearhawk. That was because the 4's were too close to the bottom end of the desired HP range. Also, the one 6-cyl block that was being aeromodded in any significant numbers was the EG33. They're scarce as hen's teeth, according to conventional wisdom. The new 6-cyl block currently being sold by Subaru was pooh-poohed as having terminally insufficient main bearing support for aero use. Is there new news? -dan fox +++ #11740 From: John Thompson Subject: Engines Think about this...how much HP do you REALLY need? Sticking a 400hp engine on the bearhawk isn't gonna make it go 200mph. I'm thinking that 200hp would be plenty for a 4 seater with a good amount of baggage, good cruise, and good fuel consumption. Think about it...how many of you are REALLY gonna be hauling hunters and a moose off a 1500' lake, since you can't hire your homebuilt out? Thats one reason why I was thinking the 4.3l V6 chevy engine. Theres another advantage of auto engines...if you need more HP, you can usually have it rebuilt for more hp. John +++ #11741 From: Budd Davisson Subject: Re: Re: AviPro Engine/Prop Prices > How about the new IO-390 (bored out IO-360, 210 hp, 4-banger)? We didn't price it and, frankly, until it's proven, I don't think I'd want to mess with it, considering the success rate all engine manufacturers have had with new engines of late. bd +++ #11742 From: Budd Davisson Subject: Re: Engine size No, the final Rover version was 300 CI and is available through most Rover dealers as it was in production in England as recently as a year or two ago, and may still be in production, for all I know. However, Bruce pointed out that the Ford V-6 is lighter and puts out more power. bd PS: Regards to "teensy 215" don't forget that's about 3.4L. Since we've changed designation systems, we tend to forget how small new engines are. Even the mighty 5.0 Mustang is only about 315 inches (probably 302 actually). That means my old Goat was 6.2L. Yikes! That makes it sound gigantic. Even the old flathead in my roadster (bored .060, stroked 1/4") is right at 4.2L and NO ONE considers a flathead a big engine (assuming they even know what a flathead Ford is). +++ #11743 From: Budd Davisson Subject: Re: Engines Horsepower isn't for speed. It's only for climb and short takeoff rolls. Speed is irrelevant for this kind of airplane. As long as you're cruising 130 mph or better, you'll get there within a few minutes of a Bonanza. If you live somewhere that density altitude isn't a problem (read that as eastern half of US), then the 180 hp BH is a terrific airplane. Terrific! As those of us in the west half of the US know, there simply is no such a thing as too much power For at least three months of the year we consider 182's to be two place airplanes or we're on the ground by 10 in the morning. Wait until the first time you're running down a 5,000 foot runway at some place like Flagstaff in August (DA 12-13000 feet) and you'll see what we mean. Even a runway that long can become scary. Cubic inches and horsepower, in that order. bd +++ #11744 From: Ken Beanlands Subject: Re: Digest Number 925 Corky, THat system is great if a coil fails, but what if the electronic switch fails.... I've always thought it was strange that an aiplane uses dual ignition, but not dual carbs. Since the most common en-route emergencies, incidents and accidents are caused by poor fuel management, Wouldn't it make sence to build a fuel system with two or more carbs each fueled by a different source? Sure, there would be more fuel management, but less dramatic results. At least partial power would be able to give more time to realize that half the system is drawing from an empty tank ;-). It would also give more options when the problen is mechanical in nature. My take on teh situation? you can sue an airplane manufacturer for using just one faulty ignition system, but not for forgetting to switch fuel tanks. Ken Beanlands B.Eng (Aerospace) +++ #11745 From: "Bruce A. Frank" Subject: Re: Digest Number 925 I have told this story before, but it may be worth repeating here. When I used to live in Utah we knocked around a couple of weekends a month in the west central desert of the state (Deep Creek Mountains, House Range mountains, Skull Canyon, etc.) in my '56 International Travelall. On several trips, during the late Sunday night return to Salt Lake City the engine would start to run rough and sometimes nearly quit. But, I never failed to make it home due to one little devise on the carb, an item missing from airplane engines even if they have a carb, the choke. If your filter, needle valve, or jet clogs grab a handful of choke and you can milk enough fuel past the clog to continue to fly (roll!). It MAY not work every time but I can truthfully say that in a vehicle with a manual choke I have never been stopped even with water contaminated fuel. (that's contaminated with water, not replaced with water). With the filtering of fuel that we apply to our aircraft fuel system installation, fuel delivery failure when we forget to switch tanks not withstanding, carbs have several "built in" ways around failure. Then again, if this single point failure becomes an obsession, one could set a dual float bowl four barrel to have the second pair of throats on stand-by (only on an auto-conversion with a Holley downdraft) 8^> (that's a smart alec grin....but only slightly in jest) The magnetic reluctor system used in many of todays distributors, no points with rubbing blocks opening and closing sticking and pitting, are pretty fool proof. I like the dual trigger mechanism in the distributor, it does not complicate and is straight forward to do so I think "why not?". Bruce A. Frank +++ #11746 From: Ken Beanlands Subject: Re: Engines > Think about it...how many of you are REALLY gonna be hauling hunters > and a moose off a 1500' lake, since you can't hire your homebuilt > out? Me please! Been there, done that , got the twigs in the floats to prove it ;-) OK, I wasn't really THAT close ;-). However, I have hauled out half a moose, and two passenger with the C-180 and it wasn't all that big a lake. Keep in mind that you are probably looking at 400+ lbs for a dressed moose, and I have typically gone with 2 other buddies and, of course, the camping gear. I'll be looking for the lightest, most powerful, most reliable engine I can get especially since I'll probably be using amphib floats. There is tonnes of good float destinations in Northern AB, BC and SK, but nowhere to base a floatplane in Calgary (dry, semi-arid praries). So amphibs it has to be. Ken Beanlands B.Eng (Aerospace) +++ #11747 From: Ken Beanlands Subject: Re: Engines > As those of us in the west half of the US know, there simply is no > such a thing as too much power the Western half of Canada is not that much better (although generally a few degrees cooler than Western AZ ;-) No replacement for displacement!! Ken Beanlands B.Eng (Aerospace) +++ #11748 From: Budd Davisson Subject: Re: Engines At least 50% of the state of Arizona is 5,000 feet or better (I'm guessing) with a third of it around 6500 feet. All of these see temps in the 100s for three months. Do the math. 8-10K DA is super common. 172's w/two people get 125-150 fpm, 182's 300 fpm and that's all assuming no down moving air. Do that a few times and you start eyeing Aztecs on the back line that don't seem to be flying much and that pair of 540's that would sure look good on the front of a couple of BHs. bd +++ #11749 From: "Greco, Bob" Subject: RE: Engines Amen to Budd's comment regarding HP vs Speed vs density altitude. My 150 hp Pacer is a single place airplane when taking off from Arizona's higher elevation airports in the summer. It's cruise is 142 MPH (in the yellow arc)so more power would not make it a better xcountry airplane but sure would help take-off and climb. Remember; speed is an inverse cube function of delta horsepower. If you want to go faster clean up the drag and you get a much better payback (Mooney 201) +++ #11750 From: Ken Beanlands Subject: Re: Digest Number 925 In answer to the "why not", basically, I look at it as another component to fail between the coils and the plugs. I'm not talking about a case where the unit doesn't switch, but more about a unit that fails and sends no output at all, even when the coils are fine. As you stated, teh coils are pretty reliable in themselves, are you sure that the swich is more reliable? You may end up wit a sytem that is heavier AND more prone to failure. KISS has always worked pretty well with me. I guess I'm a little closer to the whole RAS/fault tolerance/high availability issue as I deal with it daily here at work for our high end computing. Now, before anyone goes off and says that it's not the same because a computer going down won't kill you, keep in mind that some of these systems are controlling SCADA systems for gas and oil production. Worse-case failure can be quite catastrophic. We spend a lot of time trading off the virtues of simple, very reliable systems with complex, highly available (the type that only go down less than a couple of hours a year, and then, only when scheduled). There is a fine line where availability through redundant systems is offset by failures due to complexity. Sure, with enough dedicated people managing a complex system, we can maintain the high availibility needed. However, there is only one pilot in the cockpit of most planes and there is only so much he or she can do. Take, for example, the idea of multiple fuel tanks. Two tanks are more reliable than one in the event that a leak develops, only one tank drains. Following hte same logic, 4 tanks are better again since we can now have multiple fuel valves to provide redundant fuel flow. However, now the pilot has to remember to change the fuel tanks and watch the amounts in all the tanks. This increases the chance of failure due to operator error. The single tank requires only the most basic of fuel management...is the needle above the "E". Even then, it's amazing how easy it is for a human to forget to do this simple task. Look at teh number of people you passon teh hiway walking with red jerry cans ;-). In this example, both the one-tank and four-tank system have the same overall reliability. Factor in teh extra weight and cost of teh 4-tank system and the non-redundant system may actually be the better system. Besides, at some point, there is a single point of entry for fuel into the carb, that can fail. However, since fuel valve failure is much lower than tank leaking (theoritical assumption for the case of argument, we don't need another thread on this topic ;-) then the 2-tank system is the better of the 3 in this example. BTW, my Christavia has 1 tank ;-) Ken Beanlands B.Eng (Aerospace) +++ #11751 From: "Dan Montee" Subject: IO 360 Continentals Question for all you familiar with aviation engines. I hear a lot of talk about Lycomings and I understand that they are the preferred aircraft engine. There seem to be plenty of IO 360 Continentals around at reasonable prices. 210 HP, injected, 327lbs, seems like a very reasonable engine for the Bearhawk. What is the down side of these engines that makes them undesirable? Thanks, Dan Montee #415 +++ #11752 From: "Greco, Bob" Subject: RE: IO 360 Continentals Great engines if you get the ones with the heavy crankcase and triple remelt Crankshaft. Less expensive parts than the corresponding Lycomings. Lots of hours flying, but have a good service history, as were used in O2-As in Nam and in T-41 trainers, both types of flying which are hard on engines. Also used in Mooneys, Pipers as well as the Cessnas. Extensive research done by Mooney on service history, ADs etc prior to selecting them for the 231 and results of study gave them a better bill of health with fewer AD and service bulletins than even the ultra reliable Lyc O-320s. Smooth as glass and are easy to lean to lean of peak. Down side is there was a problem with crankshaft breakage which was never completely explained on all of the 6 cyl Continental engines. The triple remelt crankshaft which is called out on the AD seems to cure the problem. They also had some crankcase cracking problems but the majority of the cracking problems were on the 470s and 520s. The geared starters & geared alternators are more expensive when they have problems than are the automotive type used on Lycs. +++ #11753 From: Budd Davisson Subject: Re: IO 360 Continentals You've asked a loaded question, sort of a pro/anti-gun type of thing because some people swear by Continentals, some swear at them. Same thing for Lycoming. the IO-360 would be a good BH engine and you can undoubtedly do it cheaper than a 180 Lycoming. Any downsides are traditional Continental problems (boy, is this going to start a heated thread!) chief among them being a weak top end. Few, if any, Continentals make it to TBO without cracking some cylinders and needing a top OH. Lycomings can have similar problems, but not to the point that it's a problem. I, for instance, am on my 4th IO-360 Lycoming, which I consider to be the worse engine they've ever built, but every one has run to TBO and I haven't had to do a single cylinder. I've never pulled one off an engine except to do the wrist pin AD inspection. Also, the 210 Continental doesn't seem to be much more powerful than a 180 Lycoming, but that could be a perceived thing. If you can get a good engine, of almost any kind, for a good price, go for it, you'll be going through it anyway. bd +++ #11754 From: "Tony Snow" Subject: Re: Tables & Sheesh! And engines. >What is the upper horsepower limits of existing, normally aspirated >rotaries? About 160 hp at 6,000 rpm. That is an optimum efficiency of the engine in fuel consumption. No reason not to allow it to turn more like 6,500 or 7,000 rpm for takeoff. The engine is red lined at 7,500 and makes about 190 hp at that speed. Most people run a 2.85 : 1 redrive to keep prop speed down, but there are other people who use different prop strategies. +++ #11755 From: Matt Prather Subject: Re: Tables & Sheesh! And engines. I might add that some people are arguing that putting a turbo on a rotary is nearly as easy as putting an effective muffler on one. Running without a muffler is not an option without a turbo, however the exhaust note isn't bad with the turbo. The difficulty with making an effective muffler is that the exhaust gasses are hot and moving very fast every time the port opens. Heavy stainless is almost required. The nice things about the turbo are that they don't weigh much more than the muffler they replace, and increase the effective compression ratio which is a bit low on rotaries. This also should lower their specific fuel consumption. The turbo also can be used to turbo-normalize, which helps when hot and high. You don't necessarily have to crank the boost up to make the 250hp that they are capable of. The turbo also obviates the need for any kind of carb heat provision. The 'special' oil they mix with the fuel is plain, vanilla 2 stroke oil. I agree that this is probably the biggest bummer about the whole engine. I know 2 strokes can be finnicky about stale premix. I have to wonder if these things are also. If you could plumb a reliable oil injector, I could be pretty happy about that. Matt Prather +++ #11757 From: "ken wardstrom" Subject: rover/bearhawk #357 Wednsday afternoon we were ready to start the bearhawk engine. We went through our check list 3 times and agreed there was nothing but fear holding us back. Ignition on, fuel pumps on, fuel pressure up, push starter button, 2 revalutions and we're running. Oil pressure at40 @600 rpm and motor running a little rough, advance ignition to 10*, fatten up the fuel to 12.5:1 on the air/ fuel ratio meter and the rover v8 is running as smooth as silk. We do not have the prop installed so we hooked up an aux. fan to cool the motor during intal set up. We let the system warm up and stabalize at 190* then took it up to 3000 rpm. We've got acouple of old junk yard muffler to keep it quiet. This motor is SOOooo smooth and quiet its amazing.Today we ran the motor for about 2 hrs. and found we had the redive belt a little to tight when the system was fully warmed up,so we had to make a small adustment on the adjusting cam to bring it back to spec. when hot.--ken +++ #11760 From: Russ and Penny Erb Subject: RE: IO 360 Continentals Erbman's theory on why Lycoming seems to be the preferred engine: Continental has not made the IO-360 for many years (as far as I know). I'm not sure they're still making O-200s. That means the smallest engine they're making is the O-470. A fine engine for a Bearhawk, but too big for an RV. Think about the popular aircraft of the last decade: the RV series, Glasair II, Lancair 360, GlaStar--all of which typically use a Lycoming O-360. Why don't they use Continentals? Because Continental doesn't make an engine in that horsepower range anymore. Therefore, the engines you hear about most commonly are Lycomings. Hence, eventually you start to think that Lycoming must be better than Continental because you never hear about Continental. The O-470-U in my buddy's C-180 just went over 2000 hours on the way home from Oshkosh this year. It's still running as good or better than it did when he got it 1000 hours ago. I'm told it had a top overhaul for some reason at the 300 hour mark, but has run fine since then. No cracks or anything. Then again, he takes good care of it. I don't doubt that budd is right, though, since most people are shocked to hear this engine has that many hours on it. One other advantage an O-470-U seems to have over an IO-540 -- seems you can pick one up for something like $10K less. Russ Erb +++ #11761 From: Ken Beanlands Subject: Re: (unknown) Don't give up hope on teh diesels yet. Deltahawk is supplying diesels at a more "reasonable" price: www.deltahawkengines.com Ken Beanlands B.Eng (Aerospace) +++ #11762 From: Ken Beanlands Subject: RE: Continentals As a data point, we have also run an O-470-S for around 21 seasons and over 1000 hours. It had a full top O/H done around 3-4 years ago at a cost of $3400 due to low compressions. In addition, 2 other jugs were changed (actually, the same #5 jug twice) prior to the top O/H The engine is running very strong It has survived one prop strike under near full power after running up on a beach. The prop ate the nose of both floats. The crank survived without a problem. At the time (fall, 1975) the airplane had about 9 months and just under 800 hours TTSN. We bought the plane from the insurance after that and the engine was finally overhauled in late 1980 and first run in spring 1981. This certainly upholds Budd's generalization about Cont. jugs. However, the crank has proven to be quite reliable. In fact, the only other problems with the engine over the years have all been accessory related (mags, starter, altenator, carb and prop governor have all bee O/H'd since the original O/H). Considering the moist Atlantic climate environment the plane lives in and its proximity to the ocean (5 miles from the coast), the plane is in almost the harshest conditions you'll find in North America for corrosion. Add to that the fact that the plane sits idle over the winter months in an unheated hangar, and its quite suprising that it hasn't needed a full O/H yet ;-) Ken Beanlands B.Eng (Aerospace) +++ #11766 From: Budd Davisson Subject: Power to weight ratios I've been off line collecting engine weights and powers and found some interesting stuff. All of this is approximate but probably within 5-7%. The variables are which Lycoming you're talking about. -0-540 FWF weight approximately 540 pounds, 250 hp, power -to weight =2.15 lb/hp, approx $18K rebuilt -Chevy V-8, FWF weight approx. 690 pounds, iron block, 350 hp, PTW ratio = 1.97 lb/hp, cost unknown -M-14P, FWF weight approx 630 lb plus oil/air @ 60 lb, PTW ratio = 1.91 lb/hp, $16-$18K new -Ford V-6, FWF weight 500 w/mnt, cowl, etc, 200 hp = 2.5 lb/hp, cost unknown -Mazda 13B, FWF weight 435 lb, 190 hp - 2.23 lb/hp, cost approx $5K The Mazda weight is an estimate, the rest are fairly accurate and include allowances for mounts, oil radiators, props, cowlings, etc. Chevy numbers came direct from Northwest Aero. I'm waiting for costs and the weight savings of an aluminum block from them. Obviously, the bigger the engine, the more power it's going to put and the better the power to weight. Hanging over 600 pounds on the front of a BH is iffy. The Chevy for sure would need structural mods and it would be smart to do some for the M-14P. Just thought ya'll would like to see these. I'm still collecting accurate engine weights and costs, so if any one has some real world (hanging on a scale w/all the stuff on it) weights, for other engines, I'd like to hear them. bd +++ #11768 From: "Bruce A. Frank" Subject: Re: Chevy Engines >I need to find that article in Custom Planes about that guy who used >a 4.3l chevy in his amphib. As memory serves, he spent about $15,000 >for a 250hp rated engine. If you have to spend that kind of money to produce an alternative engine for your project then you just have to really want to use that engine. A mid-time Lycoming in that hp range could be had for less. At the chance of fueling the Chevy versus Ford versus Subaru versus whatever debate, in selecting particular engines one needs to look at what will have to be replace and what can be retained. First, cast cranks have been shown to perform perfectly in aviation applications in automotive conversions. Part of that is because we are not, or at least should not be, trying to extract the Nth degree of horse power production. 250 hp out of the Chevy 4.3L V-6 is at the ragged edge. That engine required expensive after market heads and intake manifold to save weight. The builder felt the stock rods and pistons were not up top the task so he spent more money. The Ford engine was originally selected because it was a first generation of light weight, easily mass produced engines that contained OEM parts able to handle the horse power requirements for the type of plane a large number of people wanted to build. The Fords come with aluminum heads and manifold, Eaton valves and lifters, rods rated to handle the horse power and pistons that were also up to the job. We switched to Wiseco pistons primarily because we found that the 3.8L came with several lower compression ratios and it was difficult to find which ration you had. Ratios went as low as 8:1 which gave up a lot of horse power. The one we wanted had stock 8.8:1 compression ratio. Wiseco produced the 9:1 so we went with it. Higher ratios were tried, notably a 10:1 piston, but the stock wrist pins couldn't handle the higher load. Bruce A. Frank +++ #11769 From: Benton Holzwarth Subject: twin-pack engines? I'd planned to stay out of the engine discussions, but had a thought I just couldn't resist tossing out -- Soloy (something like that), I think up in the Seattle area, put together pairs of engines driving a single prop shaft. Turbines, maybe. Has anyone ever considered stacking a pair of Subaru's of the 80-100 HP variety to drive a single prop flange? Would a redrive that supported two engines be less than twice as heavy as a single unit? Would the hp/lb be less favorable because you'd just have two engines with weak hp/lb? Could one make the system more reliable by designing failure modes that would allow one engine to shut down while leaving the other running (one engine on a sprag clutch)? (Could one run it that way in normal ops, akin to shutting down one on the in-line twin Cessnas?) How much would running a single alternator, radiator, etc, help to make up the difference? (Can you figure a way to run a single starter?) Is the radiator elevation vs. engine elevation critical? What could one do to reduce the height of the engines? How about a single dry-sump vs. two oil pans? Could you put carbs on the sides vs. intake runners on the top (but wouldn't it be nice to retain the stock injection?) With two engines, maybe you could rationalize running stock ignition rather than getting into all the dual/redundant ignition, switch-overs, batteries, etc. (Why yes, I do have dual ignition -- one for each engine!) Are two engines beating on the redrive just going to tear it apart? Would it take a ton 'o dampening? Benton +++ #11770 From: "zipppydoggg" Subject: Re: Power to weight ratios >-M-14P, FWF weight approx 630 lb plus oil/air @ 60 lb, PTW ratio = >1.91 lb/hp, $16-$18K new It looks to me like the MP14 is the winner, an affortable aircraft engine with more than enough horsepower. By the way, you previously mentioned 60 pounds of the MP14 installation could be placed in the aft area, what equipment is included in the 60 lbs? I checked out the MP14 as used in the Pitts Model 12, as you suggested. These mods seem to make the engine reasonable to use. The MP14 also is a clear winner in the "size of boys toys" contest. bd, now you have gone and done it, I want one!!! ;-) Rob "comrad" Gaddy +++ #11771 From: Budd Davisson Subject: Re: Re: Power to weight ratios The stuff that can be moved aft include the airstart tank and the oil tank (4.5 gallons). They could be moved behind the baggage compartment rear wall. bd +++ #11775 From: "nauman_alan" Subject: Re: Chevy Engines OK... I want to chime in on this topic. I really would prefer to go the auto engine route for my Bearhawk so I have looked at loads of options. My first choice would be a 350 Chevy. That was my first engine rebuild and it has been the easiest engine that I have worked on yet. The problem is the weight. I don't like the LS1 option because it is not a standard small block. It gets too far away from keeping things simple and it is rather expensive. If you get aluminum heads and a block, then a basic engine gets pretty expensive. I think the block is about $2K and the heads are probably another grand. That puts the engine back up around $5-6000 and I am still not sure about the weight. I kind of like the Mazda 20b rotary. I read about leaving the stock oil injection and using avaition grade oil which is supposed to burn cleaner than the cheaper auto oil. That is supposed to both keep the seals lubricated with the factory method and reduce the buildup that is supposed to be the reason that people yank the oil injection. The drawbacks I see to the 20b is that it is still fairly hard to find and expensive when you do find one. They are also all computerized so you have the whole computer conversion issue. I think the 13b is a little on the lower end for the power so I would prefer larger engine. The Sube's that I have seen are either on the small side as for power or get expensive and hard to find for the more powerful ones. Here is an interesting option that a friend pointed out to me. Anybody here up to VW power :-) How about a twin engine option? Check out http://www.altimizer.com/ where they have a twin VW package that will run two engines that are from 60 up to 180 HP each. The twin engine package with 360 HP is supposed to weigh 400 lbs! They don't have a price, but it sounds pretty cool. I will probably end up with a 4.3 Chevy V6 or maybe the Ford V6. I lean toward the GM side of the debate, but I would run a Yugo engine if it had the best properties, price, and dependability. I think I have a while before I really need to decide though. Hopefully I will be taking my flight test in about a month. I was supposed to take it in mid October, but we had bad weather last week and then the 172 was down this week for it's 100Hr so I have been bumped out a couple of weeks. I need to get my landings down a little better in the 172 before I test. The 180 HP 172 is a whole different animal than the 152. Alan +++ #11778 From: "Russ Kaye" Subject: RE: Re: Power to weight ratios You might want to check out these links. www.russianaeros.com/vedenyevproduct.htm www.gesoco.com www.culpsspecialties.com (A biplane site, but Steve's got the experience with the M-14 and is usually pretty good about answering questions) Better expect to extend that main gear a long way's or expect to plow fields with that long prop. Russ +++ #11779 From: Budd Davisson Subject: Re: Re: Power to weight ratios Thanks, Both George (Gesoco) and Steve are friends and they both know what they are doing. In fact, my brand new, Americanized m-14P came from George. As for the gear: 4" w/8.50 tires. bd +++ #11781 From: "Dan Montee" Subject: Re: IO 360 Continentals The only problem I see with the 470 is the weight. At the Oshkosh forum I heard "The Bob" say 3 times that 400lbs was the max engine wt he recommends for the Bearhawk. When Budd tried to get him to stretch a little he just repeated "no, 400lbs max". Dan Montee # 415 +++ #11782 From: "Shawn Harrison" Subject: Engines (Was Re: IO 360 Continentals) Sallee Chevrolet lists the LS1 crate engine weight as 390 lbs. If 400 lbs is the maximum engine weight for the Bearhawk, wouldn't that mean the LS1 could be used without modifying the Bearhawk structure? Shawn Harrison +++ #11783 From: Budd Davisson Subject: Re: IO 360 Continentals Just for the record: it's damn hard to stay under 400 pounds with about half of the 540's available. bd +++ #11784 From: Budd Davisson Subject: Re: Engines (Was Re: IO 360 Continentals) If the LS1 weighed 390 with the reduction unit, you may be right. But it doesn't. And don't forget about the radiator and coolant which has to be included with the engine weight because the Lyc doesn't have it. It's the FWF weight that counts, not just the engine weight. Northwest Aero says their aluminum head, iron block engine, ready to go with PSRU, etc., is 575 pounds and an aluminum block isn't going to knock off 175 pounds. I'm guessing closer to 60 pounds, if that. So....it's still too heavy without some restructuring. bd +++ #11785 From: Alan Nauman Subject: Re: Engines (Was Re: IO 360 Continentals) The LS1 is in the ballpark, but that is a dry weight and it does not include any accessories (alternator starter). You also have to add the PSRU weight. Alan +++ #11786 From: "Bruce A. Frank" Subject: Engine Weights & Stress on the Firewall For all of his mistakes Dave Blanton made in horsepower calculations, he did make some good points about the loading of the fuselage structure from the mounting of heavier engines. The really important information is moment arm, not just the weight of the engine. When I made the point earlier about the CG of the Ford being closer to the firewall than that of the original engine used on the TriPacer I was alluding to this information. If the CG of the alternative engine is located such that the moment arm is equal to or less than that of the engine installed in Proto II then there may be no need to change any structure in the Bearhawk design to support the increased weight of the relatively compact shape of a V-8. Bruce A. Frank +++ #11788 From: "Dave Roberts" Subject: Engine Weights, CG, and props All of this talk of 350 chev weights has my curiosity up. NW aero says theirs weighs 575 with psru. Team-38 says theirs weighs 460 without psru. If Team-38 is correct and you add Belted Air's 38lb psru and Ivo's magnum prop at 26lbs that comes in at 524lbs. Add 50 more pounds for cowling coolant,mount,and radiator and you are at 574. Add another 25 for the things I forgot and we are at 600lbs. Now, I've heard that a constant speed Hartzell weighs around 50 to 60lbs[correct me if I'm wrong]. And that is way out on the front. When you start figuring center of gravity as Bruce says the 350 may be more suited for the BH than we think. Wil Graf told me he thought his 0-470 firewall forward was about 500lbs maybe a little less. I'm hoping to find an midtime 0-540. But after my BH has been flying for four or five years I may have a 350 hanging on it. For the record, an aluminum block 350 is 90 lbs lighter than cast iron. +++ #11789 From: "Bruce A. Frank" Subject: Re: Engine Weights, CG, and props Did any of you see, a few years ago, an article in one of the mags about the installation of a Chevy 350 in a Cessna 172. (I think it was a 172)? More power, few complaints, weight was not a detrimental factor. Bruce A. frank +++ #11791 From: "ken wardstrom" Subject: fwf weights and balances We did an actual weight and balance on our 4.6 rover just prior to start up and the weight is 454 lbs, and the cg. is 21.5" ahead of the firewall.This is a complete ready to run weight including the ivo 80" 3 blade constant speed prop, full of antifreeze ,oil, wiring, oil cooler, hoses motormount , i mean complete.The motor is bone stock and comes from the factory @ 230 hp. @4800 rpm. in full pollution mode. With all the pollution junk removed, the tuned headers and the ignition timeing and fuel set correctly these engines are makeing an honest 250+ hp. @4800 rpm. We put an almost identical package together on a friends 24' hovercraft complete with a super quite muffler and mounted ivo's 84" paddle blades on our own full reversing hub. ( 96" dia. ) Both engines are almost vibration free and super quiet. ken wardstrom #357 +++ #11792 From: Del Rawlins Subject: Stop the Insanity! I don't think that I am necessarily the best person to be making this point, since I am one of the guys in Alaska who may need a fair amount of power, but somebody has to say this and I don't see anybody else about to do it. There has been an awful lot of talk about monstrously heavy engines here lately and I think that it needs to be remembered that no matter how well you keep the CG where it needs to be, a heavier airplane isn't going to fly as well as it should. While you can in all likelihood hang a huge engine off the Bearhawk, you will never make it into a Beaver or Murphy Moose. I respectfully submit that if you want to play with heavy engines, that there may be more suitable airframes available. Don't get me wrong, I'd love to see a radial installation light enough to be used in the Bearhawk airframe, unmodified, but unless Zoche gets off their rears I don't see it happening. Or a liquid cooled auto conversion of 200+ hp that is closer to 400# than 500. Personally I'm really hung up on the idea of having a liquid cooled engine, but I keep coming back to the fact that The Bob designed the Bearhawk around the lycomings, and the lighter variants at that. There has to be a better solution than hanging a huge chunk of iron on the front, and one that will provide the desired power at a more affordable price than the equivalent lycont museum piece. -- Del Rawlins +++ #11793 From: Russ and Penny Erb Subject: RE: Digest Number 925 True, except... What you say is true if the efficiency of the PSRU is 100%. However, the only 100% efficient systems are kept in the physics labs with the massless rods and frictionless pulleys. Knowing there will be some losses through the PSRU, what is the typical efficiency of today's PSRUs? Alternatively, how much power is absorbed by the PSRU (and thus rejected as heat)? Russ Erb +++ #11795 From: "Bruce A. Frank" Subject: RE: Digest Number 925 Certainly not loss free, but the loss is very low. The belts are made of Kevlar and rubber, too much energy dissipation and the belts start to melt. I believe losses run in the area of <3%. Years ago I had to select an electric motor power transfer setup which was virtually identical to that used in the cog belt PSRU design. With tension adjusted properly advertised power loss was below 1.5%. This is why the cog belt design is such a breakthrough. The cog belt design is right there with gear and Hy-Vo chain designs without the need for lubrication sumps, sprays and pumps. Weight is about equal or less with possibly the bulk of the units being a slight disadvantage. Bruce A. Frank. +++ #11796 From: "ken wardstrom" Subject: reversing prop The prop hub is for our own playing on our hovercrafts only. However i stopped by terry wilshires ( 80% spitfire with 350 chev ) and he told me he picked up a timed out prop from a twin otter? , The prop shop cut it down to a 96" 3blade, serviced the hub and eliminated the beta capability. I beleive he said he paid 3000 for the prop complete with the service and mods. may be a good source for reversing props? +++ #11797 From: Benton Holzwarth Subject: PSRU efficiency > I believe losses run in the area of <3%. One hp is about 750 Watts. 1.5% of a 200 horse engine would be about 2250 Watts. Somehow it's easier for me to get a feel for the heating of the belts by converting the power absorbed into Watts. Benton +++ #11800 From: Budd Davisson Subject: Re: fwf weights and balances Ken, That's good info and at 454 for the entire FWF will within weight limits (Bob says 400 pounds for the engine only, so 475 or so is good FWF) and your CG is almost identical to the Lycoming distance Bob gave me. Where did you get your engine and what did it cost? What kind of PSRU? bd +++ #11801 From: Budd Davisson Subject: Re: Stop the Insanity! First, a 540 powered airplane is more airplane than just about anyone needs. Period. End of conversation. It's all around performance and efficiency is hard to beat. The only reason to go automotive is cost. They will never duplicate the power to weight of the 540 coupled with the reliability, low complexity and the peace of mind of working with a known factor. The Lycoming is a helluva long way from perfect, but it at least is a known factor. The M-14P will add approximately 135 pounds to the airplane and decrease the power to weight ratio from 10 lb/hp to 6.9 lb/hp. To put those in perspective, an S-2B Pitts is 6.3 lb/hp but in this case the engine is delivering over twice the thrust while the wing loading stays at 13.9, even less than a C-172. So picture a 360 hp 172 with five times the thrust. It will accelerate to flying speed in no distance at all and the big prop will be "blowing" a significant portion of the wing even before moving, so takeoffs would be incredibly short. All these numbers are at 2500 pounds, so you'd be working the airplane in BH weights, speeds and distances but giving up 135 lb useful. I'd restructure enough to operate at 2600 pounds at the same G loadings, these numbers would come down slightly but useful would stay the same. Still, the Lycoming is a better idea for 99% of people. In STOL mode, power to weight, wing and span loading tell the entire story and one really good one (power to weight) can overcome a slight difficulty (increase in span loading) in another. All that having been said, there is no substitute for keeping weight out of an airplane unless the increased weight improves some performance ratio significantly enough to effect the performance positively. An M-14P does. A Chevy does not. bd +++ #11803 From: "ken wardstrom" Subject: fwf weights and balances Budd we picked the motor up from a local auto wrecker for $4500 cdn. It came out of a 97 landrover with only 2000 miles on it. It was still in the vehicle and we started it up prior to buying it. The psru is our own design and is a cog belt system.We basically looked at all the drives we could, made notes of what we liked and didn't like ( jeess i hope we didn't throw the WRONG notes away ).The complete firewall forward package minus the prop is at $17,850 cdn. ( it's a good thing mom has no interest in the paperwork ).This is hard cash outlay for materials only. We do all our own maching and fabricating, there is about 3000 hrs. labour into the fwf package.It should also be noted that dad and bob are in a close race to see who can get the most out of a dollar.While we have enjoyed this part of the project it has taken a year and a half and cost the same or more as a standard a/c package.Personally i think it all boils down to -Do you want to build or do you want to fly. - ken +++ #11804 From: Budd Davisson Subject: Re: fwf weights and balances Does anyone know if this engine is still in production, if they are available and what the going price is. Ken, if you spent $4500 for the engine, what did the other $13K go for, if you don't mind me asking? Since you did your own machining, I'm just wondering. And, if the engine only had 2000 miles on it and put out 230 horses stock, what did you do to it? bd +++ #11805 From: "ken wardstrom" Subject: rover 4.6 I don't know if the engine is still in production since bmw took over landrover but i suspect it is because it's used in a lot of different applications.It is basically the old buick 215 with some major evolutionary changes, crossbolted mains, modified heads and upgraded oil pump system.The changes we made to the motor were -remove the mass airflow sensor and restrictive air inlet ducting - remove the stock exhaust manifolds and replace them with our own long tube headers ( ceramic coated inside and out ).- replace the stock ecu with an sds programable unit from raceteck in calgary. The stock ecu is set up to produce the least amount of emmisions possible,lean burn and retarded ignition.The costs come from things like dual ecu systems dual high pressure pumps, dual primary pumps,dual msd 6a's, ceramic coating the headers, dual custom built aluminum rads etc. etc. It dosen't take long, the 4 bearings for the redrive were almost $1000 and when we added up the reciepts thats the number that was stairing us in the face.You have to remember the canadian dollar is only worth $.60 us., that puts the project at around $10,500 usd.-ken +++ #11809 From: "Bruce A. Frank" Subject: Re: engines If you do the work yourself. But you are preaching to the choir, I believe there are many workable automotive substitutes for Lycs and Conts. Piston or rotary, I believe there are enough proven conversions to fit in most homebuilts. Then again, I am not anti-Lycoming or anti-Continental. When I finish my V-6 installation, short of a prop, I will have only $2100 invested. If someone gave me a good serviceable ready to fly 0-540, 0-470 or even an 0-360, I'd use it (until it needed an overhaul, THEN I'd install the Ford). Paul Lamar said to me at Sun 'N Fun this year that if I weren't so heavily invested in the Fords I'd install a Mazda. I was talking to several people at the time and didn't have a chance to make a rebuttal. Corky has pointed both his and my disenchantment with that engine; the necessity of oil in the fuel and a complicated assembly that a shade tree mechanic may not be able to handle. My stable of V-6s ( I have 3 of them) are dirt simple to work on, inexpensive to overhaul and will last longer than I have years to fly. And while I don't *dislike* Chevys (if given one ready to fly I'd still install the Ford)..... I like Fords. +++ #11844 From: Ken Beanlands Subject: Re: Re: Stop the Insanity! The one thing I would be very concerned about with the M-14P is the availability of parts. I've been waiting for some time for the new rubber mounts for my Franklin engine. PZL has their hands full right now with a mandatory AD on fuel pumps and it's been quite difficult to get a set of mount out of them. Had I gone with a Lyc. or Cont, then this would be a non issue. There is nothing worse than being on hold for 4-6 months over some rubber mounts! Be sure that whatever you buy can be easily sourced for parts. Ken Beanlands B.Eng (Aerospace) +++ #11845 From: Ken Beanlands Subject: Re: twin-pack engines? > I'd planned to stay out of the engine discussions, but had a thought > I just couldn't resist tossing out -- Soloy (something like that), I > think up in the Seattle area, put together pairs of engines driving > a single prop shaft. Turbines, maybe. > > Has anyone ever considered stacking a pair of Subaru's of the > 80-100 HP variety to drive a single prop flange? Check the back issues of Sport Aviation/Kitplanes for just such a conversion. If I remember correctly, it was a ?-EZ with a pair of Subaru engines stacked together driving a common propellor shaft. The builders were either South or Central American as they crossed the Gulf on their way to OSH. They have had some problems with the installation mostly due to harmonics and vibration. However, it seemed to be an interesting way to get the reliability and performance out of an automotive engine. I suspect that the weight would be a little heavier than a single of teh same power, but I think it would be close. Ken Beanlands B.Eng (Aerospace) +++ #11849 From: "Andrew Rekow" Subject: Re: twin-pack engines? It was on a Cozy Mark IV http://www.infortel.com/cozy/ Featured in the May 98 issue of Sport aviation. There's a link to the artical in the above web site +++ #11851 From: Ken Beanlands Subject: Re: Re: twin-pack engines? Subaru, Suzuki, at least I was cloase with a 3-sylable, Japanese engine starting with "SU" ;-) Ken Beanlands B.Eng (Aerospace) +++ #11852 From: "Daniel Fox" Subject: Re: twin-pack engines? I crawled over that plane for 20 minutes, and I can't remember any more than what you've stated. IIRC they're Venezuelan, and the engines were non-US Geo Metro 1300cc types. But, I'm not sure. :-( I do remember that they were mounted tandem, fore-and-aft as opposed to side-by-side (both in the rear engine compartment). And, I remember thinking that the way they brought the power from the 2 engines together to a combiner was way complex. Might have been a Velocity; it was certainly a Vari-Eze or one of its derivatives. Also, I'm certain you will find a writeup in SA. If someone has a callout on that, I'll look in my back stacks for it for them. Has anyone on this list bit on the $150-for-all-you-can-eat back issues on CD offer yet? --dan fox +++ #11857 From: "John" Subject: Re: Orenda V6 engine development > From Orenda's website: NBAA Convention, Las Vegas, Oct 18, 1998........ Buoyed by the market interest in its newly-certificated 600 hp liquid-cooled OE-600A V-8 aero-engine, Magellan Aerospace subsidiary, Orenda Recip Inc., of Toronto, Ontario, is actively studying a six-cylinder variant which would deliver power in the 350 - 500 hp range. Both turbocharged and normally-aspirated engines are contemplated. http://www.orenda-recip.com/index1.htm I do't think they have done anything on it as of yet... John Kozak, #511 +++ #11868 From: "Bruce A. Frank" Subject: Re: engines >> When I finish my V-6 installation, short of a prop, I will have >> only $2100 invested. >What are you using for a PSRU? I came upon three several years ago, two original Blanton drives on engines I bought and a Northwest Aero (older design) unit I bought from Brantly Harrison (Engines by Brantly) shortly before he fell apart. After selling the two Blanton drives my cost of the Northwest Aero drive was "0". If you are interested in a PSRU I can send you several leads on Blanton low time or unused units. Bruce A. Frank +++ #11875 From: "John" Subject: more auto engines With all of the talk about auto engines, I was wondering about the Lexus engine that Toyota based their aircraft engine on. I ran across the specs for one of the Lexus aluminum block V8 engines. Their 4.3 liter V-8 produces 300-horsepower with 325 lb.-ft. of torque in the car. Of course they are double overhead cam engines so are rather complex, but I wonder what they weigh. Anyone experementing with these? John Kozak, #511 +++ #11887 From: charles.k.scott@d... Subject: Re: Digest Number 935 > I'm not anti-auto engine. When I decided to build an airplane the > only thing I "thought" I knew for sure was that I would use current > racing technology to build my durable, powerful engine. Heck, I had > built scores of winning race engines and these throw back certified > aircraft engines were out of the stone age. Yes, they are antiques > but I haven't figured out how to get a better combination of weight, > power, and dependablility out of anything else. And that's part of the whole LyContinental versus auto engine debate: You should not be holding up all the modifications being used on auto engines as proof that the flat aircraft engines are from the stone age because the use of the engine is entirely different from what autos see. Direct drive engines simply don't run fast enough to utilize double overhead camshafts with four valves per cylinder, nor do they need super trick ignition, although certainly having a spark retarder coupled to a knock sensor would be a great step forward. In a similar vein, you don't need to turn an auto engine into a full race engine in order for it to be useful as an aircraft engine. Some things just don't cross over well. Things like 10 to 1 compression pistons would force the use of special fuel. Double overhead cams with four valves per cylinder would just add weight since the engine isn't ever revved to the point where such settups are useful. No need for after market connecting rods either, if the originals have been proven in flight. No need for a forged solid billet crankshaft for the same reason. Certainly it would be useful for the combustion chambers to be of similar volume but I doubt anyone would be able to tell the difference from an ordinary, un-modified head. Having bearings derived from racing is beneficial, being able to use an aluminum oil pan would be handy. The induction device is where there would be the big difference: race engine usually have devices bolted to them that flow MUCH more fuel/air than is remotely needed for our use. Basically we prize reliability above almost all else, and accept a number of compromises so that reliability may be enhanced. That is precisely why people buy Ford V-6's and remove the fuel injection and the computer that controls it and throws it away so that a carburator can be bolted in place. This works best though, when a manifold that was designed to flow fuel and air is used. Using an air only manifold works, sort of, but can have MAJOR running problems at various rpm ranges where the fuel gets slung to the sides of sharp bends in the manifold and doesn't make it to the combustion chamber causing lean backfiring and lots of rough running. Corky Scott +++ #11908 From: "Bruce A. Frank" Subject: Re: Auto engines > Its starting to sound more like a closer to stock engine would work > for a conversion, with weight being the deciding factor (this is a > generalization). > > But what about the timing? wouldn't you still have to replace the > camshaft anyway, since we need longer runs at higher end RPM's for > takeoffs and climbs? Some engines do very well at 60-100% power with the stock cam, but any engine will improve its HP output if its breathing is optimized for the rpm at which it will run when attached to a PSRU. Going back to the engine I know best, Ford made changes to the intake on the 3.8L for the Windstar boosting its HP output to 210. I have been unable to find out if they made any changes to the cam to accomplish that HP increase. The 3.8L that I first got from a salvage yard came from a T-Bird. In stock configuration, throttle body injection and a cast iron exhaust manifold, it was rated at only 140 HP. From what I have read on some of the Mustang groups, changing to a tuned exhaust and a reprogrammed throttle body can take this "stock" engine to 180 HP. With the addition of a different cam HP can climb to 210. Then there are those who slap on the nitrous for climbing out of high altitude lakes (Mike Hirshfield in Canada). Bruce A. Frank +++ #11911 From: Tony Dean Subject: Re: Auto engines I seem to recall that Richard Finche in his book on auto conversions (which I cannot find at the moment) seemed to recommend that you leave the engine stock for the most part. Things on the outside were upgradeable but I got the distinct impression that he thought that the innards should be left alone. I can think of two reasons for this: 1) A skilled race engine builder can rebuild an engine but what about the average person? Maybe, maybe not. YMMV :-) 2) My former boss (auto shop) said that Ford has an application note out about the Duron V6 engine that recommends not to rebuild it. Seems that it is real easy to warp the aluminum block. He told me that the best thing to do is not go inside that engine at all. Don't know what the Aerostar 3.8L V6 construction is but the Aerostar 4.0L looks more like a cast iron block. Haven't pulled one out yet. Now OTOH, aftermarket intake and exhaust would probably be OK. Regards Tony Dean +++ #11912 From: mprather@s... Subject: Re: Auto engines An issue with many aluminum block engines - esp those that are foreign derivative - is that they can't effectively be bored or honed. On some engines this is so because the rings slide directly in the block material with only a silicon hardened coating to provide a wear bearier. Other engines (Nissan V6, for one) have very thin steel or cast iron liners w/o enough wall thickness to allow any real rebore. It wouldn't surprise me if one of these is true with the Al Ford engine. +++ #11913 From: Tony Dean Subject: Re: Auto engines The way it was described to me was that the engine uses long studs to bolt it together and extreme case is required to get the engine bolted back together if the heads come off. Actual lateral stress can be placed on the crank due to block warpage is what my old boss tells me. Regards Tony Dean +++ #11922 From: charles.k.scott@d... Subject: Re: Digest Number 937 > Its starting to sound more like a closer to stock engine would work > for a conversion, with weight being the deciding factor (this is a > generalization). > > But what about the timing? wouldn't you still have to replace the > camshaft anyway, since we need longer runs at higher end RPM's for > takeoffs and climbs? Most of the engine can remain stock John, but some things need adjustment. For instance, because the engine will be producing most of it's power at between 60 to 75% instead of just 10-15% for street engines, much more heat is produced. We adjust for that by modifying the waterpump in some cases, and making sure of air flow to a radiator that must be properly sized and designed for that amount of power. We also may use a smaller diameter crank pulley so that the water pump doesn't overspeed and cavitate. More heat to the pistons means they will grow more. This could cause piston scuffing if the bore is not adjusted to account for the larger (from more heat) diameter piston. When I bought the Wiseco pistons for the Ford, they came in three oversizes: .010, .020 and .030. I needed the .030" over piston because it took that much to clean up the cylinder when the initial boring occured. The machine shop operator stopped at that point because the pistons had not arrived yet, and waited until they did so he could mike them. I had ordered the .030" version, but a good machine shop waits until the pistons are in hand to measure them just to be sure. When they came, the instructions stated that they MUST have .050" clearance. These pistons were chosen specifically for the Blanton modified V-6, he worked closely with Wiseco to get the right ones, so the clearance requested is not an option, it's a requirement. Fifty thousands is a lot of clearance for pistons, I gather .015" is more common for street engines. But I repeat, in order to survive the higher heat of aircraft (or racing) operation without scuffing, that's what's necessary. Air cooled aircraft engines have even more clearance because air cooling doesn't do as good a job as liquid cooling, I'm told, plus there is a "choke" milled into the cylinder: it's more narrow at the combustion chamber than it is at the base. This is because all the heating takes place at the combustion chamber. Since it's hotter than anything else in the cylinder, that area expands the most. Incidentally, this is also why you must thoroughly heat up an air cooled aircraft engine before applying full throttle. If the engine is too cool, the cylinder will not have expanded yet. When full power is applied those aluminum pistons will pick up heat MUCH faster than the surrounding cylinder and will expand and make contact. Not good. Timing needs to be adjusted so that it maxes at about 21 degrees before top dead center. The distributer I bought allows the timing to retard for starting, and then advances to full advance with increasing throttle. For a great discussion on combustion theory and why timing needs to be advanced, see Deakin's column on "Mixture Magic" in the AVWebsite. Corky Scott +++ #11924 From: mprather@s... Subject: Re: Digest Number 937 Do you know whether the Blanton specified pistons are forged or hypereutectic? Forged pistons offer better strength but more thermal expansion coefficient than the hypereutectic alloy process. You can therefore run tighter pistons with hypereutectic pistons. You get more startup oil consumption, and piston slap with forged pistons. I guess aircraft engines are the place where you pay the smallest penalty for using forged pistons because short flights are less likely than short drives. Does your distributor allow for timing adjustment based on manifold pressure? 21 degrees of advance seems like a very small amount when combined with low manifold pressure - which may be present in cruise conditions on normally aspirated engines. Oh wait.... Are you running a turbo/supercharger? At low manifold pressures - 20", 36deg advance will make more horsepower/gas mileage. Interesting info - thanks for sharing. Matt Prather +++ #11925 From: "Bruce A. Frank" Subject: Re: Digest Number 937 Corky may have had a typo, the typical advance is 28? BTDC. With 100LL I am aware of some pushing it to 34?. Someone, I am not sure who now (seems I attributed the info to the wrong source in the newsletter), communicated to me that they ran a dual ignition triggering system; one was a crank fire setup and the other used the distributor. One trigger was set at 28? BTDC for use with auto fuel and the other was set at 34? for when using 100LL. Bruce A. Frank +++ #11926 From: "Dan Montee" Subject: Re: Digest Number 937 I'm learning a lot about the Ford motor here. I've never worked on the ford 6 but I am amazed to see some of the dimensions used in building one. Like .030 overbore plus .050 clearance. The ford has a lot of excess material in the block to allow a .080 overbore. That's unusual. .080 over is big jump in compression. Did Wiesco compensate with a different deck ht? Did your machinist clean up the block deck and the heads? If so, what did he do to the pistons to compensate? .050 piston to wall clearance. I've never installed a piston that was far from the .0015"/inch of bore rule of thumb. Even the big Lycs and Continentals fall into that range. I'm not sure what Wiseco is up to here but it's new. What rings are they using? There must be some really deep lands to allow for the piston to rock around in a .050 clearance hole. Normal rings and lands wouldn't last long with that clearance. I've found that to much piston clearance, something around .002" to .0025"/ inch of bore actually allowed the piston to grow more and scuff more do to the lack of cooling. In a high performance environment the piston needs fairly precise contact via the oil film with the cylinder wall to dissipate heat. To wide a clearance leaves the piston fending for itself in the cooling department. Service limit cylinder taper on Lyc 360/540 is .004". What air cooled's use a tapered bore? Dan Montee # 415 +++ #11927 From: mprather@s... Subject: Re: Digest Number 937 I'll stick to my original 36deg, and maybe make it even more extreme by suggesting that on certain engines, 40deg of advance will make the most horsepower on the least fuel, and not produce detonation. The typical max advance value of 24-26deg on a Lyco/Conti magneto timing assumes certain operating conditions (and fuel octane). The assumptions assure maximum horsepower at sea level mp and max hot temperatures, but no detonation. At the lower manifold pressure found at high altitude, or cruise power settings, more timing advance makes the engine more fuel efficient and produce more power. This is so because at lower mp, the effective compression ratio is lowered, cylinder filling is reduced, and flame front travel is slower. You have to start the spark earlier in order to get the most energy from the mix in the chamber. Even on a Lycoming at sea level mp, you can get away with more than the spec'ed 26deg advance. The problem is that now you are making more hp, and that is making more heat. As the CHT goes up, resistance to knocking goes down, and you can start detonation very easily. Water cooled engines have a leg up over air cooled engines because they can reject heat better. Here's a link to an interesting page that gives an idea about combustion chamber design, and how much advance is optimum for horsepower. This totally neglects ability to reject heat, and so if your cooling system isn't up to the amount of hp your making, detonation is probable. http://members.aol.com/dvandrews/timing.htm That's an interesting idea for in-cockpit re-timing. Maybe Corky was going for 21deg as initial advance, and the mechanism pushes out further based on reduced mp and increased rpm? Sorry if this is all stuff you know.... Matt Prather. +++ #11929 From: "Bruce A. Frank" Subject: Re: Digest Number 937 There could be some research on advancement. One of the reasons for the original setup of the Ford engine with 28? was the limitation of the total advance and retard. The timing had to be retarded back to 7 to 10? to start the engine. From that point with centrifugal advance only (vacuum advance is removed from the distributor) total advance will be about 28?(the mechanical limit of the distributor). Something like the MSD manually advanced ignition control might be a way to go. Only reservation I would have is that I'd like to have a knock sensor to run such tests. Bruce A. Frank +++ #11936 From: Budd Davisson Subject: Re: MP14 fuel requirements > Does the MP14 need leaded fuel? What may be the impart to operating > this engine if "low lead" aviation fuel is phased out to NO Lead > fuel? Unless I'm mistaken the M-14 is fine on mo-gas. The octane requirements start at 78, but I'm not sure about the low lead question. bd +++ #11949 From: charles.k.scott@d... Subject: Re: Digest Number 938 > http://members.aol.com/dvandrews/timing.htm > > That's an interesting idea for in-cockpit re-timing. > > Maybe Corky was going for 21deg as initial advance, and the > mechanism pushes out further based on reduced mp and increased rpm? > > Sorry if this is all stuff you know.... 36 deg. is a LOT of advance. I'll defer to Bruce for his knowledge since he prints the Ford Newletter, but I'd be a bit uncomfortable using that much advance. There is no device that further advances the timing that I'm aware of or that I intend to use. I haven't read through the newsletter on what most folks are using but 21 to 24 deg. seemed fairly concervative and safe. Bruce, what are people using? Corky Scott +++ #11955 From: "Bruce A. Frank" Subject: Re: Digest Number 938 > I haven't read through the newsletter on what most folks are using > but 21 to 24 deg. seemed fairly concervative and safe. > > Bruce, what are people using? Most use 28? full advance. Bruce A. Frank +++ #11980 From: Bob Romanko Subject: 175 HP FWF for $5,600 There you go campers: A flying, certified GO-300 with gearbox and prop: $5,600. Not bad for a bolt on 175 HP powerplant. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=1864359131 No...Mrs. Planter wouldn't let me bid! Something about my spending $32,000 on airplane stuff in the last four months has her a bit gun shy. Women. Planter Bob +++ #12134 From: Ken Beanlands Subject: Re: Oil Spills > Does anybody know if there is an alternative to PZL for get a new > Fuelpump for the Franklin. Our Aircraft is grounded by the AD and we > will need a quick solve of the problem. Company PZL said 2 Month for > getting a new pump. Crazy! Last year we needed a camshaft and it > took 4 month to repair the engine. Please contact me by mail if > there is an alternative supplier or possibility to get the plane in > the air again. > > Regards to all from Germany. The Franklin engines are neat engines with a lot of innovative features. In fact, I was so impressed by the price and features, I bought a PZL 4-cylinder for my own Christavia. Now I regret the decision. There is nothg wrong with the engine itself, it's the parts supply that can be a real problem. I've been waiting several months for some mounting bushings and still haven't received them. Here's a quote from today on the Franklin Engines list: There also seems to be a lot of squabbling between the US reps. I bought an engine from one rep and called a second to see if they could supply some parts. Basically, I was told that since I bought the engine from the other dealer, he would not sell me anything. Personally, I'm quite fed up with the whole thing. Hope this helps. Ken Beanlands B.Eng (Aerospace) +++ #12273 From: Del Rawlins Subject: Re: lom engines >>Why not a lom? Prices are low. Turbo charging available. Inline 250 >>hp or 315 radial. Radial is 480 lbs. Check out the attach for >>radial. Because the inlines are long and will make the Bearhawk look ugly. Also might screw up the CG. One of their inline fours might be better but I think the biggest one is only 160hp. I don't see what advantage their radial has over the Russian unit, which offers more power for the same weight. Take a look at the LOM powered CH801 to see what I mean; they actually succeeded in making an ugly airplane even uglier, a feat which I had previously regarded as impossible. -- Del Rawlins +++ #12274 From: Budd Davisson Subject: Re: lom engines The LOM's are really attractive, but you have to look at their hp ratings closely because they play little games with them. Each of their engines has a supercharged and normally-aspirated version and each of these versions has two hp ratings, but the difference is the rpm they are letting them turn, 2750 vs 3000, on takeoff the cruising hp is usually the same for all versions. You're right about the pricing, etc. And they are reasonably light because their main case is magnesium (no smoking within .001 millimeter) but their CG is a lot further forward. Their biggest engine is 235 hp, 364 c.i. and weighs 339. They can also use the self-contained AVIA constant speed prop. A note: their super charger control is a separate lever. Here's a paragraph out of a thing I just finished on a LOM powered GlasStar that has some info in it. The factory still makes their entire range of engines. They vary from the delightful little 75 hp Mikron III (149 cubic inches, 151 pounds!) to the 240 cubic inch four-bangers that range from 120 hp to 160 hp (231 pounds to 250 pounds) and their bigger, 364 cubic inch, six-cylinder engines that deliver 180 hp to 235 hp. All of their engines share the same compression ratio, 6.3:1, and are good to go on any fuel in the 78-100LL range, which means they are all happy running on mo-gas. The obvious question is why the difference in the horsepower given the same compression ratio and displacement? The answer is in different takeoff rpm and supercharging. That?s right, part of the series of engines uses gear-driven superchargers while others depend on rpm for increased horsepower for five minutes on takeoff but drop back for continuous cruise. For example, their 180 hp M137A gives 180 hp at 2750 rpm and 160 at 2680rpm (max continuous). The M137B at 195 horsepower and has the same specs but it has a takeoff rpm of 3,000 rpm. It is not known whether there are any internal differences in the engines. The M337A is 210 hp at 2750 rpm on takeoff but is supercharged, hence the increase over the same engine (M137A) putting out 180 hp at the same rpm. Got it? Good! Their radial appears to be another M-14 derivative: same disaplacement, stroke etc. Their webside has all the pertinent poop, www.moraviation.com/ bd +++ #12277 From: Del Rawlins Subject: LOM engine length I found the length of an O-540A to be 38.42" according to an old issue of beartracks. The 235hp LOM six is 54.9" long, or about 16.5" longer than the Lycoming. Since the 540 is already pushing the CG limits as-is (as evidenced by the requirement to mount the battery in the tail), mounting a LOM 6 might be asking a little too much, since not only is the engine arm longer, the prop will be that much farther out as well. -- Del Rawlins +++ #12279 From: Budd Davisson Subject: Re: LOM engine length It doesn't have to go in the tail. Behind the baggage compartment is fine. In the kits we put tabs back there so you can mount a track and mover the battery for and aft about 18 inches. bd +++ #12281 From: Budd Davisson Subject: Re: LOM engine You're late. Go back about three messages and you'll get some good opinions concerning CG and looks. The biggest problem is making a cowling that doesn't make your airplane look as if you slammed the hangar door shut on it's nose. I've flown the 160 hp version (When it was called the Walter) in the Zlin 526 a couple hundred hours. It's smooth and has a great, raspy exhaust tone. I like the Avia self contained prop (no governor on the engine, it's all inthe spinner dome). I did blow the top off of a cylinder head, but we did nothing but hard akro in the airplane, so it's excused. As they come from the factory they have the baffling attached so installing them is easy. They run around $13K, give or take a K. The best bet is still a 235 hp, 0-540, mid time for the same money. You can't beat cubic inches. (LOM is only 360). bd +++ #12370 From: Tony Dean Subject: Re: Another ford engine conversion At Copperstate I went to all the Auto Engine conversion workshops I could. At these workshops I heard from people who have already done things like this and have had various levels of success. A guy there had built up a ford V-8 but the costs did eventually rose higher than a mid time engine and probably would continue to be higher. The Team 38 people were also there and they explained that all the mods that they do for aviation purposes are not designed to gain even one more horsepower. These mods are strictly for longevity and they are not cheap. Some of the big issues? Burned valves, ruined valve guides, cooling issues, and accessory failures. The Team 38 people run the water presure higher to prevent steam bubbles from forming at high loading/rpm. This means the entire cooling system has to be rated for 32 lbs rather than the usual 16. At the end of the week I was almost in dispair about auto conversions. If you do an auto conversion that has not been done before just assume that you are now an engineer and will be doing the engineering for this. Also assume that you will incurr engineering costs much like a manufacturer. Why engineering? Because you will be working with an engine in an environment and modes of operation that are untested and the engine was not designed to address. This does not make conversions impossible but difficult. Of course Richard Finch, (who was not a spealer) in his book, recommends that you go with a proven conversion. If its already flying, you do not have to pay for the up fromt engineering costs as did the person who did the engineering. Just send them a check when you figure out how much money they saved you, then do it again when you realize that your earlier estimates were way too low. :-) If I do an auto conversion, I think I will better know what I am up against and will give it a lot more thought. For example the guys in Boulder with Raven Redrive had a good presentation. His most important point, for me, is that the Suzuki engines are designed to run at higher rpm and loading than most auto engines. In normal highway operation these engines run in the 3-4k rpm range rather than the 2-3k of most auto engines. This is a point worthy of note. Of course the four bangers are too small for a B'hawk but the V-6 from the Grand Vitara is not. However I have no idea if that V-6 is designed for the higher rpm that the four bangers are. So if you do an auto conversion. Do it for the reduced maintenance costs. The initial costs may not be that much better but, if you pick a conversion that someone has already done with reasonable success, your long term maintenance costs will be much less. At teh end of the week, I told the guy from Team 38 that the weeks worth of auto conversion talks had almost scared me off from an auto conversion. He voiced the long term costs argument and the follow the known path argument and I felt much better. Oh, the other reason you may want to enineer an auto conversion? Because you want to. Nobody doing this is making money off just the conversions. Voluse of sales is too low. But if you want to, well, why not. After all why build your own airplane when tripacers are so cheap? Do it for the personal satisfaction. Regards Tony Dean +++ #12379 From: Ken Beanlands Subject: OT: C-180 Starter We are in need of a new starter on the C-180. the preference is for one of these new high-speed, light weight starters. Anyone know who manufacturers them? has anyone had any experience with these, good or bad? I guess it's ot that far OT as Budd is selling O-470 mounts for the BH ;-) Thanks, Ken Beanlands B.Eng (Aerospace) +++ #12380 From: "teyeomans" Subject: Last post for the" Ford" Bearhawk in New Mexico. After some more engine tuning work and waiting for some good weather I decided to go fly last Monday. During the preflight I noticed some movement in the propeller redrive bearings that bothered me. Soooo No Flight. After dissasembly and inspection I could find no problem with anything in the drive system..All the bearings felt perfect. I have about 20 hrs on the engine doing tests and engine tuning things with 10 hrs logged in the air. After listening to several people at Copper State I only got more confused. Got excited when Bruce was on the list of speakers (Sorry you weren't able to be there Bruce). I am also very confused about the HP I am getting, The prop people say around 150-160 but I can't make the fuel burn look right. The performance of the plane corrosponds with the fuel burn numbers, of less than 100 HP. At any rate I made the decision to have Bob build me one of his BH 360 engines and hang a constant speed prop on it. I still think that the auto engines are a good thing but It takes much more time getting everything working as planned, than I now want to spend. I don't want to discurage anyone from going with the auto.... I have my system out and will be down until at least April.. I will be selling the stuff I have including the engine, belts, sprockets, Electrompotive ignition system, racing radiator, and Warp drive prop. Thanks to everyone that helped me get the cooling system working. If I wanted to take more time to work on the machine I'm sure it would be fine, engine sounds great. But the neighbor has a 160 lyc. in his RV-6 with 200 hrs the first yr. GRRRRRR. Let you know how I feel after the winter hybernation. Tom (back to the shop)Yeomans 075 +++ #12381 From: Brian Cox Subject: RE: OT: C-180 Starter I'm flying with a couple of IO-470s in the C310. They both have the old style heavy starters - Teledyne part no. 646275RX (Delco-Remy). I was anticipating the day when I may need to replace or repair them, and checked out the Sky Tech and Lamar units, which are both permanent magnet units (starters are Nippon Denso?). I think that ElectroDelta (Kelly Aerospace) also advertized that they were coming out with a similar unit. If you could just drop them in place of the old Delco-Remy units and save about 8 lbs. then it may be an attractive alternative. I checked out some newsgroups (www.google.com. rec aviation groups). The opinions that were expressed were that the starter adapter may also have to be replaced when the starter is replaced. The consensus that I gathered was that the lighter starters spin faster, which is the reason for changing the starter adapter. Some reported that bolting the starter on the existing adapter would soon result in a failed adapter. At the end of the day, it seemed that the lightweight starters had a lot of fans for Lycoming applications, but results weren't universal for the big Continental sixes. When it comes time for a new starter, I decided to stick with overhauled Delco-Remy units. They've done fine on my bird for 36 years, and I am not in dire need of an additional 8 lbs. payload. I had very good luck this year in getting both generators overhauled at Aero Tech of Louisville, and also purchased solid state voltage regulators from them. The charging system on the plane works great, and I invested less than $1000 to get the new regulators and have both generators overhauled (actually exchange units). When I need a starter, I'll have them do the work. Brian Cox, #478 +++ #12382 From: "Bruce A. Frank" Subject: Re: Digest Number 970 First off, take Richard Finch's recommendations with a large grain of salt...he is not flying an auto conversion YET and many of his conclusions are out of left field (including a lot of his welding information). All of the things you mention have been learned over the years with the Ford engine (and were learned FIRST with the Ford V-6), but some people have to reinvent the wheel. Tony, Several Ford 3.8L V-6s have exceeded 1500 hours and one I know of has gone to 2000 hours with no, let me say again, no problems. With the number of Ford V-6s flying we have made all the mistakes with nearly 100,000 cumulative hours. As I say in the newsletter, experience with Ford auto-conversions is applicable to most other auto conversions. +++ #12385 From: "Bruce A. Frank" Subject: Re: Last post for the" Ford" Bearhawk in New Mexico. Sorry I could not make it at the last minute. I am also sorry that so many seem to have come away with a less than positive view of auto conversions. The prior art on auto-conversions is there if these new guys on the block would take the time to research what has and has not worked. One wonders why they want to do a presentation at Copperstate if they do not have definitive answers. Bruce A. Frank +++ #12387 From: Tony Dean Subject: Re: Last post for the" Ford" Bearhawk in New Mexico. I think I went into the last day a bit downhearted but I think I cam away with a view that the auto conversion is more doable than it was 10 years ago. I think I may be closer to an auto conversion than I was befoer Copperstate but with a more realistic viewpoint. OTOH: If I do an auto conversion, I think my chances of success are much better than they were. I think I have a better idea of where the big gotchas are and when to consider beefing up the engine or suport systems. I understand the issues surrounding high pressure coolant systems in aviation better and what the impact is from a design perspective. I was probably a bit too optimistic and hearing from the Team 38 and Raven Redrive people gave me a list of issues that I will need to be sure I address. I think the issue of using a proven design and a well tested platform is more important than ever. Regards Tony Dean +++ #12391 From: "Bruce A. Frank" Subject: Auto-Conversions (Long) I really do wish I had made it to Copperstate to hear what was said in the forums about different automobile aero-conversions. Let me put out a few rules of thumb. If the engine is highly modified, such as significantly higher compression pistons or radical cams or has to run at a higher rpm than was rated by the factory, to produce the necessary horse power for your application then that engine may not be the best selection. Even though many automobile applications run around town at 2000 to 3000 rpm todays engines are usually HP rated at 4800 rpm or higher. The testing process to which the factory subjects todays engines exceeds anything ever done to certify a Lycoming or Continental . Automobile engines are loaded to full horse power rating and run WOT for hundreds of hours. Tests included surges back and forth from peak torque to peak horse power with periodic drop back to idle....a very severe test. Typical auto engine bench test is 400 hours with randomly selected engines tested to 1000 hours plus. One of the reasons that both the Ford 3.8L and the Chevy 4.3L V-6 engines are selected for homebuilt application is because of their wide spread use by their manufacturers. Literally millions of these have been installed in the automotive model lines and have been for 20 years, producing a lot of information that gives us a basis from which we can extract potential capability in an aircraft. An indication of longevity may be that the salvage yards are full of them because there is virtually no replacement market. In the beginning with the Ford, and a little later with the Chevy, the manufacturers saw that cutting corners on rods, pistons and cams was a surefire way to get an expensive recall. Factory installation of top of the line components in these engines has allowed us to obtain OEM engines that required little change to make them durable. The closer to stock one can run an engine the more advantage one can take of those factory components and test procedures. When looking at a potential engine conversion for your aircraft, if you can find a version of the engine, produced by the factory, that closely matches the hp requirements of your application you are several steps ahead of the crowd. Not that you have to buy that particular version, but you know that the basic structure can support the out put you need. I fully believe that any automotive engine can be used in an airplane if the operational parameters of that engine are matched to the requirements of that airframe. Look at all those model T and model A engines used in early aviation. Truthfully the majority of problems in auto-conversions are related to ignition and cooling. Most of the shortcomings of the, at least the cogbelt design, PSRU have been fixed. Even early designs still out there have had fixes invented that eliminates past problems. Virtually every call I get with what the builder considers insurmountable problems can be traced to ignorance of what has gone before. Some people are very resistive to accepting the fact that their "new" idea has been tried before and didn't work. They scrap the engine project rather than take to heart the information developed by others who have been successful. Let me say also that the installation of a complete Lycoming or Continental or LOM engine is easy....literally a "no brainer." Hundreds of thousands have been installed and the factory has done all the research. If you follow their instruction manual placing the baffles and the oil cooler where specified and your cooling air induction holes are not too small you'll likely never lay a wrench on the thing until that first top overhaul. Selected models of Soobs, Fords, Chevys and Mazdas have proven themselves airworthy, but it takes more research on the builders part to do the installation so as to obtain the same problem free operation of that Lyc or Cont. Such problems as carbs coming apart and dropping into the induction system or spin on oil filters backing off from vibration are almost funny specifically because such things have all been addressed in auto-conversion literature.....it may not be laid out cook book style, but the information is there. I have found it interesting that people are irritated that they have to follow the suggested procedure of allowing engine coolant and oil to reach operational temps before calling for WOT take-off power in an aluminum headed auto conversion. Whereas similar specifications on the aviation engines including warm-up and full power time limits are just taken in stride. I happen to think that Fords are a better choice for certain amateur built aircraft, but I am not so myopic to think that many other engines will not fit the bill. There have been a lot of mistakes over the last 20 years of auto-conversion development. Some of those have cost lives. No less can be said of the early evolution of the Lyc or Cont. Auto conversions are a viable choice for amateur built aircraft and most, if not all, of the information necessary to build a durable safe power plant is available with a bit of effort. I'll climb down off the shipping crate (couldn't find my soap box) and invite anyone who has questions to email or phone me if they have unresolved problems. I am not an auto engine expert on every aspect of installations in every plane, but a terrific amount of information passes through my hands in creation of my newsletter. Bruce A. Frank +++ #12399 From: "Bruce A. Frank" Subject: Auto Engine Conversion Cooling I hope my knees can hold up to stepping up onto packing crate so frequently, but I'd like to pass along some stuff about what is going on in the water jacket of an auto conversion. First (hoping not to over use that phrase), most auto engine conversions installed in aircraft are turned around backwards from the position used in the automobile installation. In many cases this positions the normally down-end of the engine in, at best, at a level angle or, at worst, higher than the opposite end of the engine. This tends, in some cases, to trap air bubbles in the high end where there it is less likely that they will be swept away by the coolant flow. On the Ford engine it is recommended that a small diameter bleed line be connected to that high end or the water jacket and ported back to the suction side of the water pump. Another thing that usually needs to be done is to slow down the water pump by either increasing the water pump pulley diameter or decreasing the crankshaft pulley diameter...or both. Contrary to many published reports this is not to "slow down" the coolant flow to allow more "dwell" time in the radiator, but to eliminate cavitation caused by the high speed rotation of the water pump impeller. That high speed impeller literally can whip the water/antifreeze solution into a froth that can transfer little heat from the block to the radiator, but that high speed cavitation of the OEM impeller also prevents very little coolant flow. Besides slowing the pump rotational speed there are mods that need to be made to the impeller itself to improve pumping. If you thumb through speed/racing catalogs you will see a product from a company call "The Brass Works." They make a little disk that attaches (usually with "pop" rivets) to the face of the impeller. This closes of the face of the impeller preventing the "spilling" of water as it travels through the pump, forcing the coolant to go out to the tips of the impeller blades. This dramatically improves flow, allowing good circulation even to remote mounted radiators, and helps a greater volume move through the block. Installation of a high pressure coolant system works because it collapses these cavitation bubbles, not so much that it prevents steam bubbles formation in the heads. If you are flowing the coolant and removing "trapped" bubbles then hot spot steam bubbles just do not form at the horse power levels we are extracting from these near stock engines. We also use an "expansion tank" which is placed so that it is the high point in the coolant system. This is usually designed to be out of the direct circulation of the coolant....usually "T'd" to the upper radiator hose. The expansion tank does two things. It provides a compressible air space in the system so that as the coolant expands from the heat of the engine coolant does not have lift the cap and spew into a catch tank (which brings more dissolved oxygen into the system....another topic for another time). But, the most important function of this "expansion tank" is to allow air in the system to escape the water jacket and stay in a place where the flow of coolant cannot re-entrain it into the circulation thus improving quantity of coolant flow. This is just a light review of water cooling . If you have questions just ask...then again I'll probably think of something else I didn't say. Bruce A. Frank +++ #12400 From: charles.k.scott@d... Subject: Re: Digest Number 972 > I happen to think that Fords are a better choice for certain amateur > built aircraft, but I am not so myopic to think that many other > engines will not fit the bill. I agree with all Bruce says and the fact that I'm building a Ford V-6 for my airplane has nothing to do with my concurrence. ;-) The only thing that is unfortunate and unfixable (without spending a lot of money) is that the Ford is not hotrodded and therefore there are no aftermarket intake manifolds for it. This means that a fair amount of machining and modification of the manifold is required in order for it to flow properly at 4,000 to 4,800 rpms. This is unfortunate as Edelbrock has any number of manifolds that bolt to the Chevy V-6, which is widely modified for street rods. I'd much rather take the route of using someone's engineered and tested manifold than to machine down and modify my own, even if the modifications are known to work reasonably well: it's still not like having something engineered for the proper rpms from the beginning. Oh well, on the other hand, Ford's valves are considered the industry standard and don't require any modification or substitution at all. Corky Scott +++ #12421 From: "Bruce A. Frank" Subject: Radiator Placement (another long one) This is getting into one of my favorite discussions about cooling and radiator placement. You have probably heard/read the statement that air can't be pushed through a radiator, it has to be sucked through. That is pretty close to true. Close enough to truth that if one designs with that mechanism in mind cooling problems are virtually non-existent. A while back the Canadian version of the EAA had reams of information about facilitating cooling of water cooled aircraft engines posted on a chapter's web site. Many people read that info, but missed the point. Many began to think that they had to build a belly scoop radiator housing like the one on the P-51 Mustang. What those scoop builders missed was an understanding of the principals that those pages presented. Two things need to have attention paid to then when designing the radiator setup in a water cooled aircraft. One is to provide adequate cooling. The second thing is to accomplish that cooling while keeping drag to a manageable level. A radiator sticking out in the high speed air stream allows very little air to flow through. Most of high speed air piles up in front and spills around the edges and the radiator acts more like a flat plate drag devise instead of a cooling devise. To reduce drag and at the same time supply air at a slow enough speed to easily pass through the relatively restrictive radiator core there must be ducting of some kind. The idea is to take high velocity take air in to a "duct" that acts as an expansion chamber; diverging walls that causes the air to spread out and slow down, and build pressure, before coming to the radiator. Then on the back side of the radiator there needs to be a duct, or at least a plenum, that accepts the volume of air coming through; converges to accelerate the air, then dumps it, at near slip stream speed, into a low pressure area around the cowl. You can create a low pressure behind the radiator that can suck air through the radiator even without the incoming duct. In some cases that can work, but there have been cases where the air spilling out of a short intake scoop actually pulled air backwards through the radiator...reverse flow, but at too low a rate to cool properly. Radiators placed at the front of the cowl can cool if there is effort to exhaust the air from the cowl into a low pressure area. (The most common method with both air cooled and water cooled is to have a gap between the bottom cowling and the firewall with a lip on the cowl's trailing edge...this induces a low pressure area that pulls the air out of the engine cowl.) But, a lot of spilling intake air disrupts smooth airflow around the cowl and adds to drag. Ideally the intake opening is sized just so that it allows the right amount of air to enter so that all of it passes through the radiator and exhausts from the cowl back into the slip stream. The intake scoop accepts its slug of air and the air that misses the intake opening flows smoothly along the contour of the outside of the cowl. There is no build up of excess air in that intake that has to spill back out around the opening to disrupt smooth airflow. I seem to be repeating myself here, but I hope the picture is somewhat clear. It has been calculated that intake ducts work best when the walls diverge at about 7 degrees, but to accomplish divergence from intake opening to the size of the radiator will take a longer distance than we have room in the cowling. In practical application divergence as much as 15 degrees still works pretty well to drop velocity and increase pressure without inducing so much turbulence as to reduce the needed volume. Making modifications to the cowling (like rear facing louvers to the cowling sides helping to draw suction on that exhaust side plenum) to create a greater suction on the back side of the radiator can help when the intake duct is less than perfect. Because of the fluid dynamics involved with some kind of intake ducting I am not enthusiastic about front placed radiators, though, as I said, they can be made to work. Two designs and slight variations on the theme seem to work well virtually all the time. One is to install the radiator with the top against the firewall and the bottom sloping forward contacting the bottom of the cowl...a variation of this setup is to lean the top of the radiator forward sort of nestling it up against the oil pan and placing the bottom back against the trailing edge of the cowl short of contacting the firewall (leaving an open gap between the radiator and the firewall). Baffling is used to keep the air from the intake duct segregated in the lower part of the cowling so that the radiator sees mostly fresh air (read that as cool air) The radiator must be well sealed in its position to the cowl and/or firewall so that air cannot bypass it. A very small gap around the radiator can allow nearly all the air flow to bypass. Similarly, the exhaust side of the radiator must have a well sealed plenum or duct so that the suction from the low pressure exit point does not pull air from anyplace other than the back side of the radiator. Dedicated ducts to the radiator offers the coolest air, but several I have seen just allow all air entering the cowling through a scoop and the openings around the prop to exhaust through the radiator (again well sealed so exiting air cannot bypass the radiator) This method picks up the heat from the block and exhaust manifold reducing the efficiency of the radiator...but it has been made to work. The gap between the bottom cowl and the firewall is the exit point for both forward tilting and rearward tilting radiators. This space is hardly more than a plenum and it has been found that a forward tilting radiator gives room for a curved plenum wall leading down to the bottom of the firewall improving efficiency slightly (very slightly). The size of the opening between the cowling (or radiator if the radiator's bottom is to the rear) and the firewall need be only about 2.5" to 3" wide and the width of the radiator to do the job (with a lip on the trailing edge of the cowl). The other method is to place the radiator flat on the bottom of the cowl and use either adjustable or fixed louvers (flaps, slats). An example of this can be seen in one of the pictures I posted to the Bearhawk Group site built by Mike Hirschfield (paint scheme is a mid stripe consisting of a chain link design.). The rearward facing louvers create the required low pressure area. Some builders have created a bumped lower cowling that provides a plenum area with the opening only at the trailing edge. The adjustable slat method seems to provide more trouble free (fewer overheating problems) operation. This radiator can be fed from a dedicated duct or general cowling air with the same temperature limitations as mentioned above. Some have questioned the fact that the flat lying radiator requires the ducted air to have to turn 90 degrees to pass through it. If you have slowed the air and raised its pressure with divergence of the duct this configuration does not present a torturous route and does not increase drag. If you duct the radiator cooling air there still has to be air flow into the upper cowling to feed the carb and cool the engine block. Exit for this air can be smaller and off to the sides of the radiator exit or provided by side louvers in the cowl (Like the old Packards). Some build shields around the exhaust pipes to reduce radiated heat and allow upper cowling air to exit around the exhaust pipe through its hole in the cowling. (Very helpful to reduce under cowl temps when using non-dedicated air flow through the radiator) Now the reason not to exit the radiator air at the top of the cowl is because it will have to exit near the wind shield. Though this seems like a good (or logical) idea because heat rises and the heat seems like it might keep the windshield from icing there is a major problem. That area is a high pressure one. Remember the muscle cars that had the scoop turned backwards towards the windshield rather than forward towards the relative wind. Even at highway speeds this windshield area provided an minor carb pressure boost. If you want to try it as a feed area for the carb on your plane let me know how it works, but my point is that this is not a low pressure area. Again rear facing side cowling louvers can work if you want an up flow through your choice of radiator location. But, for the most part, with a properly designed air intakes and exits. prop wash provides adequate cooling even for extended ground time. I have seen bottom of the cowl cooling air intakes designed as NACA scoops feeding upward with an exit plenum dumping out the sides of the cowling. It worked once the builder realized that the intake air was striking the scoop at and angle because of the corkscrew flow created by the prop. By remaking the NACA scoop so its intake was oriented into the relative wind it worked fairly well. One last thing, a lot of louvers in the sides of the cowl exhausting a lot of slow moving air into the slip stream can add a lot of drag; if you have a high speed slick plane it could make some difference. In the V-6 STOL (and thus probably the Bearhawk, even though it is faster than the STOL) experience shows it seems to have little impact on cruise or top speed. Bruce A. Frank +++ #12422 From: Alan Nauman Subject: Re: Radiator Placement (another long one) There used to be a bunch of information on the web about the cooling of the WWII planes. One of the topics that I remember (other than the ducting that you just discussed) was the turbulent airflow coming off the prop. They said that it was very inefficient to have the air coming off the prop feed the radiator because it was tumbling and, as such, would not transfer the heat very well. The solution was the belly scoop or hanging twin radiators from the bottom of the wings. I like the idea of laying the radiator down under the engine and isolating the airflow through it, but I am still concerned about the drawing the air that close to the prop. I was thinking that something more like a cargo pod with a radiator in it would work. The drawbacks are the additional plumbing and the additional drag. Do you plan on adding an oil cooler to the radiator too? I was thinking about the ones that zip tie to the radiator. I know that in cars, a lot of heat is transferred from the car's oil pan hanging down in the air flow. With the aircraft mount, you loose a lot of that cooling. Alan +++ #12423 From: Budd Davisson Subject: Re: P-51 radiator Last year before he died, Leon Atwood, former President of North American put out a paper that explained the P-51 scoop and, as Bruce says, it's a lot more than an air-in-air-out situation. Atwood said the way they accelerated the air out the back of the scoop not only eliminated the scoop drag but actually added a sizable amount of thrust to the airplane and aided it's speed. If you look how small the inlet area is (about 10" by 18"), picture a radiator behind it standing up in the fuselage that is a solid two feet square. The plenum lets the air expand and slow down like crazy and the back side has a long, slow constriction exiting a hole that's even smaller than the inlet. It has a flap on it that opens automatically via temp controlled servo so on the ground or at slow speeds the exit is much bigger. I had a Mustang in the late '60's and had to rebuild the scoop (it had been belly landed) and it was a real bear because the inside of the scoop is as finely shaped and finished as the outside with a number of compound skins. bd +++ #12425 From: charles.k.scott@d... Subject: Re: Digest Number 974 > Would you care to speak to the issues on placement of the radiators > and the air flow through the cowling? I would think that the air > intake and radiators would be low and to the front with the exit > high and to the sides or even the top. Bruce is the best source for relevant information on radiators and placement. I have a few comments to add to his very comprehensive post. People building auto conversions have by now installed radiators in almost every position imaginable and most work. Some work better than others but there are interesting problems to work through. One of the successful installations was Jerry Schweitzers V6 STOL in which he mounted a large radiator horizontally under the oil pan. He had a standard nose bowl and just let the air come in through the two openings and wash past the engine and exhaust system and then go through the radiator and out the bottom of the cowl. This is sort of a worst case scenario, in that the air got heated by the engine and exhaust system, not to mention the engine is not a very smooth object for air to flow by. But darned if it didn't cool the engine without any problems. When he mounted a Ford in an RV4, he did things differently, he mounted a small race car radiator below the engine and routed air directly to it from an opening below the spinner. This was much more efficient and he found he did not need openings as wide as were required in the V6 STOL. Car radiators aren't designed to be used in airplanes. They will work, but you have to deal with several problems: They have a big cross section which tends to make them tough to fit anywhere and they have very narrow fin spacing which makes efficient flow through them problematic. I've read that auto radiators are designed to cool cars that are sitting still running in traffic with their AC on. Don't know if that's completely accurate or not but it seems reasonable. There are companies that design radiator specifically for the conditions our airplanes normally see. These are radiators race cars use. They are smaller in cross section, are thicker and have wider fin spacing. What radiator should you use? Well the radiators designed for race cars assume forward motion, they won't cool sitting at idle for very long. Airplanes need to be able to cool while sitting on the ground for an indefinate period. I spoke with a race radiator shop and we discussed what would work. I'm looking for a radiator that will cool an engine that produces 200 to 250 horsepower (mine won't produce that but the excess is to make sure I cool on the ground). I figured a cruise speed of between 120 and 130. They had such radiators sitting on the shelf. They are wider than they are tall and are fairly thick with wide fin spacing. In addition, the problem of ground cooling has had my attention for some time now. My plan is to use the exhaust flow to augment the cooling. I'd do this by routing the exhaust tubes around behind the radiator and terminating them about halfway into a shroud. The exhaust flow produces a jet affect which accelerates the air around it thus augmenting the flow behind the radiator. The faster the air flows, the lower the pressure. So the augmented flow does two things: 1. it accelerates the flow behind the radiator which helps pull the air through and 2. it lowers the pressure inside the exit duct which also augments flow through the system. This isn't pie in the sky thinking, exhaust augmentation has been used in a number of airplanes, most of which were air cooled. A guy installing an auto conversion in his pusher found that he could not cool his engine for ground tests, using even partial power. He cobbled together an exhaust augmentation system and found he could run the engine to full power for as long as he wanted. This was written up in Contact! magazine. The Canadian website Bruce mentioned was written by a guy who is convinced that radiators in the noses of airplanes don't work well. He cites the turbulence from the prop which chops up the incoming air destroying any constant flow. He's a fan of belly mounted radiators the like for which the P-51 Mustang is so famous. But the reality of building means that belly mounted radiators aren't always the best choice. For instance if you were to want to fly off the water, the spray that would be produced would certainly glut the ductwork. Then there's all that tubing that must be routed to the engine and back and the installation becomes heavier and more complicated.. I almost did this anyway, just because I had the Ford Taurus radiator and that's practically the only place it fit, given that I have a Piper Tripacer nose gear to deal with. But a properly sized racing radiator will fit beneath the engine back by the lower edge of the firewall. I even have enough room to route ductwork to it. Sorry Kent, it will likely be fiberglass as it will be somewhat serpentine. Corky Scott +++ #12432 From: "Bruce A. Frank" Subject: Re: Radiator Placement (another long one) > I was thinking that something more like a cargo pod with a radiator > in it would work. The drawbacks are the additional plumbing and the > additional drag. > > Do you plan on adding an oil cooler to the radiator too? I was > thinking about the ones that zip tie to the radiator. I know that > in cars, a lot of heat is transferred from the car's oil pan hanging > down in the air flow. With the aircraft mount, you loose a lot of > that cooling. At least in the generic Ford installation the oil pan sticks down into the "duct" that carries "cool" air to the radiator. We also use the Modine Donut oil heat exchanger which circulates radiator water to both warm and cool the oil. I don't see that "tumbling" air off the prop presents any different problem for a radiator than for the airflow through the fins of an aircooled engine. Also could be differences in those planes' speeds compared to our planes' speeds. But, Alan, note that I was relating what works, not a theoretical postulation on what "might" or "should" work. Every successful Ford flying out there is using the same or near same setup. Let me address some of the information about Jerry Schweitzer's set up that Corky mentioned. Jerry intended to fly aerobatics in his RV6. His installation runs a dry sump thus he has no oil pan sticking down into the lower part of his cowling. With all that space he mounted the radiator horizontally with duct work rather than attaching it to the bottom of the cowling. One interesting bit of information, Dave Blanton originally designed the V-6 STOL with a radiator mounted in the aft fuselage cooled with air scoops sticking out in the wind. Other variations on that theme have put scoops on the sides of the fuselage rather than Blanton's top and bottom. Along with this aft radiator placement Blanton's cowling allowed the oil pan bottom to stick out of the cowl. The Modine cooler works well all by itself though some, for instance Jerry Schweitzer again, have added an airflow type oil cooler, which can take oil temps almost too low. I have a bunch of aluminum finned heatsink material, from my old days of dabbling in electronics, which I will be bolting to my oil pan for that little bit of added insurance. +++ #12433 From: "nauman_alan" Subject: Re: Radiator Placement (another long one) I just wanted to bring up the question of the air turbulance. It seemed have some logic to me. I too had thought about the heat exchange with the air cooled engines and this theory. Please keep up the posting with regards to the auto conversions. I really like the idea of the air to coolant heat exchanger for the oil. I have a friend who melted down the transmition in his Dodge truck when the transmition fluid froze(or close enough) in the extra cooler. I may be in Texas now, but I grew up in Montana. Do you have to go with a dry sump to have room to mount the radiator right under the engine? Will it make much difference in the CG to move it back the little bit to mount angled to the rear? I know that weight is a concern, but would an electric fan be worth it's weight to help the air flow while running on the ground? Thanks Alan +++ #12438 From: mprather@s... Subject: Re: Re: Radiator Placement (another long one) I have seen installations that included an electric fan. Some of them work, however some people report that they disrupt flow, reducing ratiator effectiveness. Other people report that they had problems with them because in flight they over speed. This is all hearsay, but something worth considering. I wonder if the ones that overspeed do so because they don't have the air slowed down before forcing it through the radiator. Then again maybe they were just running a cheap fan... Matt- +++ #12436 From: "Lee H. Erb" Subject: Radiator Placement (another long one) As great as an engineer Bob Lichten was, he placed the fan inlet on the XV-3 right in the most negative pressure spot there was on the fuselage. I had fun designing some successful inlets on helicopters that might apply to airplanes at takeoff powers and speeds. Lee. +++ #12438 From: "Lee H. Erb" Subject: Re: P-51 radiator I thought Lee Atwood said that it did not have thrust. Some people at Bell tried to say the same thing on the Bell 212. All it did was great a big drag wake that reduced the effectivenes of the vertical fin and more turbulence on the tail rotor. Lee +++ #12439 From: Russ and Penny Erb Subject: RE: Re: P-51 radiator I'm not sure what Lee Atwood said, but it is not unreasonable that thrust would be produced. Think of the cooling duct as a ramjet, with the heat interaction in coming from a radiator instead of burning fuel. I'm sure a Merlin running hard is rejecting a large amount of energy into the coolant. If nothing else, if the thermodynamics aren't producing thrust, at least they're reducing cooling drag, which was the point the Bruce started out to make. If you'd like a real thermodynamic challenge, try figuring out why a steam injector on a boiler works. The seemingly impossible part is that steam taken out of a boiler at a given pressure is used to inject water into the same boiler at the same pressure. I think I've almost got it--the key seems to be "phase change". Russ Erb +++ #12445 From: Budd Davisson Subject: Re: Re: P-51 radiator I'll see if I can find the original write-up but he definitely said it created thrust. I'm pretty sure I can find that and it makes extremely interesting reading and should be must reading for anyone doing anything with radiators. bd +++ #12446 From: Tony Dean Subject: Re: Re: P-51 radiator Here are a couple of links. We have the same discussion raging in the Mustang II group right now, and yes it is probably my fault. Another datapoint worth thinking about is that the P51 was a low wing aircraft and I believe I read somewhere that the best location for a high wing aircraft is different. htt://www.airspacemag.com/asm/mag/supp/jj99/Mustang.html and http://www.inforamp.net/~raac/CoolingSystems/Part1/CoolingSystems1.HTML Yet another datapoint. The jet effect from teh cooling system is somewhat speed sensitive and at lower speeds will offset the drag but may not actually produce net thrust. I'll take some improvement over none at all anytime. Regards Tony Dean +++ #12450 From: "Bruce A. Frank" Subject: Re: Re: Radiator Placement (another long one) Bayard DuPont ran a fan on the radiator of the rear engine in his Defiant for two years with no trouble. With his original belly scoop set up there was not enough air moving to cool the rear engine when holding for long periods. The fan, found in a salvage yard, operated with no problems with nothing to stop it from rotating when turned off during flight. We heard those stories of problems because of continuous rotation, but Bayard certainly had none. He has since change the rear engine cooling airflow design to one powered by exhaust system eduction. Bayard also uses a special radiator from Ron Davis Racing that is a shaped like a rectangular box...about the size in which a dozen long stemmed roses would come....about 6" X 8" X 32" long. There is no longer an under belly scoop, there is a NACA scoop ducted properly (correct smooth divergence) to the radiator. the back side of the radiator dumps the hot air into a properly designed convergent duct augmented with a venturi suction using the engine's exhaust. The exhaust augmentation allows 20+ minute ground runs with no overheating. This radiator, or one very similar, is used by Belted Air Power with their Chevy installation in their RV6. I do not know if this has changed as I haven't seen it in a couple of years, but when I saw it the upper part of the engine compartment was baffled to create an plenum fed by the cowl intake holes on each side of the spinner. This fed the carb, but also the rectangular shaped radiator mounted at the firewall. Plenum air flowed downward through the radiator. I do not know how the air exhausted from the cowl. Air to the radiator had to be very cool since the exhaust headers were below the baffling. Apparently the prop supplied enough airflow to keep things cool on the ground. Bruce A. Frank +++ #12448 From: charles.k.scott@d... Date: Thu Nov 7, 2002 4:11 am Subject: Re: [Bearhawk] Digest Number 975 I have that article Lee Atwood wrote and can confirm that the cooling system as designed does produce some thrust. It does not produce enough thrust to actually augment speed, but it does produce enough thrust to **ALMOST** eliminate cooling drag. When you understand that cooling drag is a significant percentage of overall drag, it becomes clear why the Mustang was the most efficient fighter of WWII. My recollection is that cooling drag almost canceled out under very specific conditions: at high altitude and a very high power setting. Corky Scott +++ #12558 From: "Bruce A. Frank" Subject: Re: Firewall Seal > Does anyone know of a good fireproof or fire resistant foam type > material that might work as a seal between firewall and cowl? I'm > flying a Kitfox I built several years ago and have never been able > to get a good seal around the firewall. The normal 3" wide seal > material you see in Wicks and Spruce catalogs really doesn't do the > trick. Thanks for any suggestions. > > Jim Dewberry, 440 In a past job I researched a double stick silicone foam tape that could handle 600 degrees F. If that might fit the bill, I'll see if I can find the information again. Bruce A. Frank +++ #12559 From: "Bruce A. Frank" Subject: Re: Firewall Seal In general, silicone based foam can be used as a fire stop in building heat and air conditioning ducting construction. Sandwiched between two layers of metal it exceeds building code requirements for longevity when exposed to heat. Bruce A. Frank +++ #12560 From: "Bruce A. Frank" Subject: Re: Firewall Seal Here is a sample of the dozens of types of sealing foam silicone products listed in McMaster-Carr. A search in http://www.McMaster.com finds other products reinforced with fiberglass and felt, open cell, closed cell and skinned products. Bruce A. Frank +++ #12566 From: "Tim" Subject: Re: Firewall Seal Look up Fibrefrax.....Looks similar to fiberglass mat/cloth Longeze guys use it on their firewalls ACS&Wicks carry it. 321Tim +++ #12741 From: Budd Davisson Subject: Re: props > You said 3-blade hartzell props are available. Do you have a price > for the 0-540 3 blade model? Not right off hand. I'll have to get that for you. My personal feeling, however, is that it's not worth the additional expense. Unless you're using a three-blade like a Whirlwind, I've never found enough performance difference to justify the cost. I once did a pretty thorough investigation of props on a Pitts S-2B. I flew it with the stock two-blade, the MT three-blade and the Hartzell composite, super-akro, ungodly expensive ($30K) three-blade. The three blades were definitely smoother but with the MT no matter how I tried, I couldn't find a measurable difference other than when you were dead stopped on the top of a verticle and digging your way over the top of a push-over or something you could feel a little more thrust. With the Hartzell there may have been another 150 fpm rate of climb, but this is on top of 2,600 feet per minute with a stock prop and didn't seem worth $30K. The Whirlwind three-blades are the only experimental props I'd personally trust because they are actually well-proven akro props and they definitely increase the thrust because of their different blade profile. On some engines you see as much as 25% increase. That being said, for all we know they'll increase the climb but slow the cruise. We're investigating them for one of the demonstrators but will probably go with a 84" two blade. I'm basically too much of a pessimist (read that as chicken) to want to fly behind an experimental prop. But, that's just my personal opinion and I know a lot of folks disagree. bd +++ #12744 From: Ken Beanlands Subject: Re: Re: props On the C-180, there is a mod available to use a 3 bladed propellor. However, the reason's were not for performance. The three reasons given in the literature (and I'm going from memory, I olly investigated it at OSH in 92!): More prop clearance = less prop erosion from shorter 3-bladed prop. Shorter blades = less noise for ops in noise sensative areas Good looks (OK, this one is somewhat subjective) I remember watching the 180 as we ran the plane up on the shoreline and being amazed to see a perfect waterspout form under the prop drawing water up into the blades. The noise issue is even more relavent on teh 180/185 especially with the stock 88" seaplane props. These things are NOISY. When you operate out of a lake near a community, it's certainly neighbourly to do whatever you can to reduce the noise level and not annoy them. Dad had decided long ago to swap the prop with a 3-bladed model when the time came that the blades could no longer be repaired. Ken Beanlands B.Eng (Aerospace) +++ #12745 From: Budd Davisson Subject: Re: Re: props The shorter diameter for seaplane ops is something I hadn't considered, probably because you seldom see Pitts Specials on floats (now there's a funny image). bd +++ #12775 From: "Dan Montee" Subject: Wanted: 540 Lycoming suggestions I have a question for those of you familiar with the 540. I've been searching for a 260hp 540 core. I've found a source of imported engines where I would have several to choose from. ( as related to me, the 540 is the preferred engine for drug running. High HP, low weight, and easy to work on. These engines are from confiscated aircraft, no logs) I am familiar with the common aspects of engine condition and how to evaluate them but my lack of familiarity with things like aviation carburetors, magnetos, makes of magnetos, etc leave me lacking. I don't know what carb goes with what engine, what carb model is preferred, what mag and how to identify them, preferred engine model #'s, etc. Any general information you all can share would be appreciated. Thanks, Dan Montee +++ #12779 From: charles.k.scott@d... Subject: Re: Digest Number 1005 > I have a question for those of you familiar with the 540. I've been > searching for a 260hp 540 core. This is actually why I chose to go the auto conversion route. With a no log engine, you can easily buy a very expensive mess of trouble. You have to tear that engine apart and have things like the crank and connecting rods professionally examined and measured. Well, you can probably measure it yourself but I don't have an inside micrometer to use on the cylinders. When I was searching for an engine, any engine, I did a lot of research on aviation engines and just got really put off. The excessive tolerances that are allowed for piston fit and bearing clearances would give a precision engine builder nightmares. Add to that the problems with starting in cold weather, which Vermont has in abundance and the requirement of a heat muff to heat the cabin which can and has killed people when carbon monoxide leaked into the muff and I finally decided to stop looking. The decision wasn't made lightly, I did come up with a Continental 0-470 at one point, and even had it in my shop sitting on the floor. But it did not have all the equipment I was led to believe it would and the lack of things like Mags, generator, starter, carb (pressure carb), manifold and just about everything but the actual engine itself, which had hangar rash and was missing a pushrod and pushrod tube. Plus it seemed excessively heavy. This was the military version of the engine and was purported to have no hours on it. After agonizing over the situation I resold it. Being an ex auto mechanic has it's benefits. I can choose to build an alternative engine and won't be confused by how to do that. What I can't do is the kind of precision milling and prep work the guys who build racing engines for a living do routinely. But at least the parts I give them to work with are ordinary everyday engine parts that all their machinery can handle. But the proof is in the running of this engine and I really need to build it and successfully run it before I can talk much more about what a good deal it will be. Corky Scott +++ #12780 From: "Brian Cox" Subject: RE: Wanted: 540 Lycoming suggestions I had previously found the type certificate data sheets (TCDS) for engines and propellers on the FAA website. Just for reference, I had posted several of them that Bearhawkers may be interested in on the Bearhawk group files section. Check out E-295.pdf. It is the TCDS for the O-540. The models of carb listed include the MA 4-5 and HA-6, depending on which model of O-540. Note 8 lists the magnetos. Looks like they typically use Bendix mags, but I'm sure there are also suitable Slick replacements. Others have reported in the past that they don't like Bendix mags. I used to have a Mooney M20C with O-360 and Bendix mags, and my current C310 has IO-470s with the Bendix shower of spark mags (S6RN-201/205). Performance has been very satisfactory. The -20 and -1200 models have retard breakers. Brian Cox, #478 +++ #12803 From: pfflyerz@c... Subject: Re: Wanted: 540 Lycoming suggestions A few years ago, I called Bob Barrows to ask him many of the same guestions you are asking, for just the same reason. By the time I got off the phone I realized it didn't make any sense for me to go to all the trouble when Bob knows exactly what it takes. I place the order for my engine, with him, on the spot. Still a wise choice if I had it to do over again. Pat Fagan +++ #12828 From: "collinc2002" Subject: Lycoming starters I am about ready to do the engine cowl. I know that the two prototypes do not have a starter or electrical system. Or come to think of it does proto 2 have a starter only? Seems like I heard it did, looked it all over at Oshkosh but forgot to notice. My quesion is, is the starter going to fit behind the nosebowl and look all nice and purty like Bobs' or will I need the nosebowl with the starter bump in it. Aircraft Spruce sells both models (MC-3A, MC3B) Maybe a starter without the nose on it like the Sky-tec HT series would work? Heavier and more expensive? Don't remember if this was discussed before. Collin Campbell #370 +++ #12831 From: Russ and Penny Erb Subject: RE: Lycoming starters Proto II has a starter and a battery, but no alternator. Hence, it does not qualify as an "electrical" system. Bob pulls the battery out and puts it on a charger as required. Russ Erb +++ #12833 From: "collinc2002" Subject: Re: Lycoming starters So as I suspected, Proto II has a starter. Do you know if the standard starter was used or something different? This is really what I wanted to know. Collin Campbell #370 +++ #12881 From: pfflyerz@c... Subject: Re: Lycoming starters > My quesion is, is the starter going to fit behind the nosebowl and > look all nice and purty like Bobs' or will I need the nosebowl with > the starter bump in it. I imagine Bob uses the Skytec starter on Proto 2 as that is what he supplied me with the O-540 he built for me. Bob's starter fits behind the nose bowl, without the bump, and so does mine. Pat Fagan +++ #13094 From: "fourthwedge" Subject: Re: Sixth Anniversary... > We fired up #232 for the first time today. Started right up and > sounded oh so sweet. Thanks to Bob Barrows for a great engine. In the Dec. issue of SA on page 10, a letter to the editor written by a former FAA engineering inspector named Cork Biemond, strongly recommends running an untested (never flown) experimental aircraft engine for 3 or 4 minutes at full power with the tail tied down, to simulate the take-off power and attitude requirements. Is this something you plan on doing? I had never read of someone doing this for that length of time but it makes sense if it doesn't hurt the airplane or the engine. What about the engine overheating and wouldn't you have to have some special provision on the Bearhawk to keep from damaging it or could you just tie the tail wheel down? I remember seeing a picture of Bob doing a thrust test on one of the proto's but that may have been just a short burst? Just curious about the test procedures you're planing. Somehow I knew a Barrows engine would be a good one. Congratulations on your progress and best of luck. Dave +++ #13352 From: Drew Schumann Subject: Big engine v. little engine I'm interested in everyone's opinion on engine size in their Bearhawk. It seems every other day I waver between building mine with an O-320/360 or going "whole hog" with an O-540, or maybe something in between, say an O-435 or O-470. There is a bunch of people I have a lot of respect for who habitually build "as light as possible." So I have a natural affinity toward the smaller engines. Anyone out there want to comment on which way to go? I'm familiar with the tradeoffs necessary with building light. It seems as if a small engine Bearhawk will probably get done what I "need" an airplane for. Having said that, why would I need to go bigger? Thanks for your responses in advance. Drew +++ #13354 From: Budd Davisson Subject: Re: Big engine v. little engine The reality is that a 180 Bearhawk is a heck of a lot of airplane. It'll perform with a 180 Cessna. Unless you're working a lot of terrain or density altitude there is no reason to build a BH with more than 180 hp. It'll surprise a lot of folks with that engine. As long as it's kept light. bd +++ #13355 From: "Brian Cox" Subject: RE: Big engine v. little engine I see one of the advantages of the Bearhawk is that it can accomodate a six cylinder engine. I would venture a guess that a mid time O/IO 470 would be less expensive than a mid time Lycoming 4 cylinder engine. It's simply supply and demand and most homebuilts can only use the four cylinder engine. I've owned a Mooney M20C with O360 - a really sweet airplane and bulletproof engine - so I'm not biased against Lycomings. I have most experience with the big Continenal sixes, having once owned a T207 with TSIO 520, and now fly a C310 with a pair of IO 470s. They'll weigh a little more, but I think the 470 is the engine I will eventually hang on my Bearhawk. Brian Cox, #478 +++ #13358 From: "luscombe68017" Subject: Re: Big engine v. little engine It seems that nobody ever mentions the Cont IO360. Wouldn't it be a happy medium between the O360 and an O470 or O540? 6 cylinders and 210 HP? Prices are better than 4 cyl Lycomings, what with all the RV builders and such. Just a thought, John +++ #13362 From: Drew Schumann Subject: RE: Big engine v. little engine Interesting answer. I seem to recall that even the O-435 is reasonably priced. While the GO version I hear is a bear to overhaul, the Continental line is also very attractive. Drew +++ #13364 From: Tony Dean Subject: Re: Big engine v. little engine From a pure economy perspective the smaller engine might be the more practicle. High utility with very high economy on the balance. I had almost ruled out an auto conversion, but encouragement from Bruce Frank and others has kept that avenue open. A few weeks ago someone posted Al Wicks web site from a GlassCockpit discussion. Turns out there were some other interesting things there. One was a Subaru 2.5L engine conversion for a Cozy MkIV (4 place). He also has a page on carving his own propeller. No need to dig, here is the link: http://members.aol.com/alwick/ Now the Soob is at the very low end of the B'Hawk range of HP but it may still be viable. Al tells me he has 180 hours on the engine. Bruce should be able to point you to resources for larger conversion if you are interested. After being a bit depressed about auto conversions after Copperstate, I kept running into ppl with conversions that have 180, 250, 300 and more hours on an auto conversion. My engine is still way off but I have not ruled out anything. As you said, I'm also interested in everyones opinion. Regards Tony Dean +++ #13378 From: "Montee, Dan L." Subject: Prop & Engine combinations I have a zero SMOH Hartzell prop that match up with the 300hp IO540K1A5. I don't have an engine. I would very much like to use this prop on the BH. Since the K1A5 is about 470 lbs. it is not a candidate for the BH. I am looking for opinions on using the prop on the lighter weight, lower HP 540's. I've hesitated to ask this question knowing that I would hear it wasn't certified with other engines and that there is risk due to harmonics and vibration. On the other extreme homebuilders are using auto engines and homemade reduction units which I have to assume have untested prop combinations attached to them. Is it uncommon for home builders to mix & match certified engines and props? How sacred is this ground? Just looking for opinions. Still learn'n Thanks, Dan Montee # 415 +++ #13379 From: "t18cox" Subject: Re: Prop & Engine combinations That prop probably fits other Lycomings. Give me the model number and I'll look at the Type Certificate. It is not uncommon to use constant speed props on engines other than the one called for in the TC on homebuilts. Bill Cox #303 +++ #13383 From: Russ and Penny Erb Subject: RE: Re: Big engine v. little engine I'm far from an expert on this, but here's my guess. You don't hear much about the Cont IO360 because there's not that many of them around. The only aircraft I know of them being used in were the Air Force's T-41C and T-41D. I don't think they're in production anymore. This tends to lead to them being hard to find and hard to get parts for and costly to maintain. Anyone who knows better than me feel free to jump in and correct me. Russ Erb +++ #13384 From: bearhwk272@a... Subject: Re: Re: I0-360 Cont The I0-360 is used in the aircraft that Russ mentioned plus... Piper Arrow, Mooney, Piper Seneca, Cessna Skymaster, Maule. It is a good engine, not many AD's but a little more $ to overhaul. Very smooth. The volume is low and not all shops will overhaul them because special tooling is required for some of the cylinder work. Kevin +++ #13385 From: "Anthony Walker" Subject: Big engines vs Little You may want to consider a PSA engine. In Pilot magazine (www.pilotweb.co.uk)in August 2002 there was an article on a diesel PSA (Peugot) turbo engine that is being used on a Jodel plane. The designer Jaques Vion and Jean Delemontez are using a 2,100 cc motor that performs as a 180hp gasoline engine would. They are selling kits for engines up to 2,500 cc. The 2,100 cc engine uses 2 -2.5 US gallons per hour (10-12 litres) in the cruise. Jaques Vion has done a lot of testing on these car engines, and tested 10 engines non-stop until failure occurred after 12,060 hours for the first engine (valve stem broke) and the last engine failed at 16,000 hours. Regards Anthony Walker +++ #13389 From: supermexgarza@a... Subject: propeller tip speed http://www.altimizer.com/propspd.html "propeller tip speed caluculator" while looking around reading about props i found this, click the hyperlink abobe it will take you to a site in wich you enter a few variables rpm, prop diameter, and temp, Javier Garza +++ #13390 From: Drew Schumann Subject: RE: Big engine v. little engine Thanks for all the responses. They were very informative. In some cases they helped me decide what to do, and in others they helped me to not decide until later. As I am an A&P working in a repair facility, I'm going to go with an airplane engine, as, doing the math, the automotive engines really aren't that big of money savings for me, plus, they are harder to work on, develop, and have a little more risk involved. I'll be looking for an engine in the 150-200 hp range, and will build light. Whatever comes my way between now and then that is a good deal will probably be "IT". Again, thanks for all the input. Drew +++ #13391 From: Tony Dean Subject: Re: Big engine v. little engine One more datapoint on the auto conversion. I understand your issues and they look like you went through a reasonable evaluation. The last datapoint to add to the auto conversion issue is long term costs. Upfront costs may not be significant but longer term maintenance costs are significantly less than a comparable horsepower aviation engine. td +++ #13392 From: "rodsmith52" Subject: Re: propeller tip speed Thanks Javier Thats fun to play with, amazing how much affect temperature has on the speed of sound. The latest Northern Pilot magazine (Oct/Nov) has a great article on propellers. A Cessna 185 floatplane pilot was looking for a better prop. His belief was that he wanted to swing the longest prop he could at the 2850 redline to get best thrust. He hooked up with Mr. Muhlbauer of MT propellers and they tested several props on his plane on the same day and under the same conditions. They used a spring scale to measure thrust like Bob Barrows does. They tried 86 inch metal 2 and 3 blade props and MT 82" 2 and 3 blade props. The peak thrust for all the props was close to 2600 rpm and fell off considerably as the 2850 rpm limit was approached. The highest thrust was measured with the MT 82" 2 blade prop. These results are sure an eye opener. I've been thinking I would use a 3- blade prop on my Bearhawk for smoothness and increased low-speed thrust. Wont do it if I can have as much or more thrust with a lighter, cheaper 2 blade prop. Rod Smith #246 +++ #13393 From: "Bruce A. Frank" Subject: Re: Big engine v. little engine I am probably not impartial, but then if I could obtain an new 0-540 for the small amount I have spent on my Ford engine I would fly with it. But the prices, and that is not the only consideration, are significantly higher with a certified type than with an auto engine. A zero time Ford or Chevy V-6 with reduction drive, doing the engine work yourself, all accessories included, buying a PSRU, will set you back about $6,000 to $8000. If you threw it away and built a new engine at 1000 hours you'd still be miles ahead at the aero engine's 1500 to 2000 TBO. On a Ford or Chevy cranks, pistons, cams, rods or even heads can be bought more inexpensively, by half or less, than most equivalent parts on the aero engine. As for safety, auto engines producing near factory specs for horse power and rpm output will last to and beyond that magical 2000 hr TBO. The one disadvantage, which is not as significant as you might think, is that most auto conversions weigh more than an equiv. out put aero type. +++ #13411 From: "ken wardstrom" Subject: v8 bearhawk We ran #357 for 3 hrs. yesterday to test the cooling system. So far everything is working. We started the motor and set the idle at 1000 rpm. to let everything warm up. Once the water temp stabalized at 185* we began slowly applying power, holding at each setting to make sure we didn't have problems showing up. Test observations - (1) - the motor will idle @ 500 rpm all day and stay cool (2) - the motor will run @ 65 % loading all day and stay cool (3) - with auto mufflers installed for testing the whole package is so quite that at 65% power you do not have to raise your voice to carry on a conversation. An interesting comment from the neighbour " I thought you guys said it was going to be noisy, this thing doesn't make any more noise than my car. " (4) - the return water temps at idle was 95* and at 65 % power was 110* - if our calculations are correct we should not see the motor temp climb above 185* until the return water reaches 155*. On to more testing - ken +++ #13416 From: "Bruce A. Frank" Subject: Re: Big engine v. little engine > Somehow, I expected the additional input. It raises a few > questions. > > 1. How many automotive conversions out there have 2000+ hours? One 2000 hour plus 3.8L V-6 in Ken Mitchell's BD4. A couple of others that I have had contact with who have 1500 and 1800 trouble free hours. > 2. If it takes nearly 10 years to put 1000 hours on an extremely > easy to maintain and reliable O-320/360, that would cost about $8000 > with about half time on it, or even less without logs, how > significant is the savings compared to the additional risk of flying > an automotive conversion? To what increased risk are you referring? > 3. What is the ACTUAL, vs. hopeful thinking statistics of relative > safety of automotive v. aviation engines? Early problems with the Ford were engine idiosyncrasies about which we learned through experience. Other problems were from failures to follow the directions on assembling, mounting and cooling the engine. Today, problems that show up are all related to the latter. If you want to get into statistics you will have to do that search yourself. As for the feed back I receive, problems are the same as with certified type; fuel exhaustion, control miss-assembly after inspections, and so on. > 4. Last time I checked, there wasn't very many good options for > redrives for the Ford V-6. Has this changed? When was the last time you checked? Northwest Aero has been producing a top of the line, absolutely trouble free cogbelt unit for Fords for years. Belted Air Power produces another that has been fit to Fords. Mike Hirschfield in Canada produces another excellent belt drive and the last two issues of my newsletter provided just short of blueprints on how to do it yourself using a chevron toothed cogbelt design. > I'm not anti-automotive conversion, I'm just waking up to some of > the cold, hard realities of aviation, the more I work on aircraft. > > I'd welcome as much input as possible on this subject, as my wife > and I would love to find a less expensive way to achieve our dream > of owning our own aircraft. If you have doubts about auto conversions based on perception or some actual event don't let anyone talk you in to using one. We have the know how, based on almost 20 years of flying Ford 3.8L V-6s, to build dependable, durable trouble free auto conversions using no exotic devises or expensive racing cranks or rods. We have acquiesced to the use of an after market Wiseco replacement piston for uniform compression ratios. Chevy engines (4.3L V-6s) are close behind and are likely to become more popular because there are more parts from the hot rod and racing crowd that bolt on to the Chevy. But here is the rub, pushing those engines far beyond the engineering designed horse power or rpm is what will lead to catastrophic failures. Mazda Rotaries seem virtually bullet proof, and now with exhaust gas temperatures and noise coming under control this may be the perfect choice for the bolt-it-on and fly crowd. Paul Lamar's rotary email group can likely tell you everything you need to know about flying a Mazda....along with all his reasons for not using piston auto conversions. A couple of last points, factory test procedures on auto engines exceed anything done to certify aero type engines. Running steady state in an airplane is easier than up and down the rpm and load scale of automobile applications. There are no inherent weaknesses in automotive engine designs that expose us to higher failure rates than with Lycomings, Continentals or LOMs. But there are a lot of stupid people who want to yank the engine from the salvage yard and fly it. Bruce A. Frank +++ #13417 From: Drew Schumann Subject: Re: Big engine v. little engine Actually, as we've corresponded in the past, I WANT the option of an auto-engine conversion. The only redeeming value I've found from the aero-engine bunch, is the standardization and simplicity of the certified engines. I know how to work on them and how to keep them cool, because I'm going to school to do that very thing. Northwest Aero and Belted Air Power no longer sell or support Ford conversions, as of 6 months ago. The additional risks of using auto engines are mainly centered around the redrive, and the many failures thereof. The biggest difference between certified and auto conversions is that the certified engines are designed to take the side-loads put on the engine by a direct-drive or an incorrectly designed, manufactured or installed redrive units. I'm also a little dismayed by the NTSD's accident reporter, which consisted of equal engine failures of certified and auto-conversions in the last couple months. Well, looking at the great majority of the certified vs. automotive conversions, that's not a good ratio. Still, you can buy a half-time certified engine for about the cost of the properly converted auto engine, and fly it for the next 10 years before needing the expensive overhaul. Unless I can be convinced otherwise, that's where I'll be going. Drew +++ #13418 From: Tony Dean Subject: Re: Big engine v. little engine I should have qualified my comments a bit more. I was looking only at the lowest end of the horsepower scale. I was specifically looking at Al Wicks Subaru 2.5 L conversion that he has about 180 hours on. This is in place of an O-320 in the 150-160HP range. Al says he has about $6200 in his conversion and a mid time O-320 is not much more. My main point is that the start up costs are only part of the cost of an engine during its lifetime and a rebuild of an Auto engine at TBO (determined by the builder) will be much less. Even if you have to rebuild every 1000 hours or even every 500 (engines have got past the 1000 hour mark reliably) the lifetime costs of an auto are less. The data about auto engines has grown and the hours are climbing every year. Another issue is safety. Years ago Paul Lamar used to be avidly and lividly anti auto conversion. In one of the long running arguments on R.A.H. (Rec.Aircraft.Homebuilt on Usenet News) was pro and con on auto conversion. One day Paul posted NTSB data on auto engine failures. I read it and could not believe what I was seeing. Paul had just posted the antithesis to his argument against auto conversions. The data he posted showed that auto conversions were prone to exactly the same problems that amature installed aviation engines had. Mostly support systems, cooling, and improper maintenance. The numbers of "Catistrophic" failures that we were lead to expect simply were not there. Your comments on saving more as you look at the larger engines are very apporpriate. Best Regards Tony Dean +++ #13419 From: "Bruce A. Frank" Subject: Re: Big engine v. little engine > Actually, as we've corresponded in the past, I WANT the option of an > auto-engine conversion. The only redeeming value I've found from > the aero-engine bunch, is the standardization and simplicity of the > certified engines. I know how to work on them and how to keep them > cool, because I'm going to school to do that very thing. > > Northwest Aero and Belted Air Power no longer sell or support Ford > conversions, as of 6 months ago. Yes, but, several builders have contacted me saying that there was not much to change to adapt a Chevy PSRU to the Ford. Haven't tried it myself, but there are many out there that have PSRUs which were never or only slightly used. > The additional risks of using auto engines are mainly centered > around the redrive, and the many failures thereof. The biggest > difference between certified and auto conversions is that the > certified engines are designed to take the side-loads put on the > engine by a direct-drive or an incorrectly designed, manufactured or > installed redrive units. Which redrive failures are you talking about? Blanton had some qulity control problems with some of his later drives but many just keep on running (such as the Blanton 2000 hour unit on Mitchell's BD4) Dave Sharples has a Blanton PSRU on a Ford in a Pawnee in Australia used exclusively for towing gliders. After some initial problems, again with quality control, with the Blanton drive Sharples has racked up 500 hours of extremely abusive service. And it just keeps on running. > I'm also a little dismayed by the NTSD's accident reporter, which > consisted of equal engine failures of certified and auto-conversions > in the last couple months. Well, looking at the great majority of > the certified vs. automotive conversions, that's not a good ratio. Did you find the nature of these failures? > Still, you can buy a half-time certified engine for >about the cost > of the properly converted auto engine, and fly it for the next 10 > years before needing the expensive overhaul. Maybe! You possibly have an inside line on engines. Corky, who subscribes to this group, tried for a good while and never found one of these complete with accessories engines everyone tells us is out there. What Corky found, and several others I have discussed it with, is that the engines that appeared to be good buys needed so many parts and related work that overhauled engines were a better deal. You may luck in to one. I found a GPU with the equivilent of a Continental 0-470 (Packette) for a song, but it needs everything including an overhaul (which I find more daunting than overhauling a V-6). > Unless I can be convinced otherwise, that's where I'll be going. I would never try to convince you otherwise Bruce A. Frank +++ #13420 From: Tony Dean Subject: Re: Big engine v. little engine Could you comment on something. or possibly point me to further information on the subject? I got the information second hand so I am just trying to verify an issue that may be easy to resove or not. I have run across a couple of cases where the "Problem" with a redrive was that the builder had over-tensioned the belt. The description I heard was that the cog belts do not need to be highly tensioned like V and Serpentine belts but the builder was unaware of this issue. The builder(s) proceeded to apply the kind of tension to the redrive belt and this caused excessive wear on the bearings and undue stress on the crank. I was told that, when the builder replaced the parts, he found out how to install the belt properly and had not seen the same problems again. Is this a common problem? Also, how does one go about designing a "Preventive Maintenance" program around an auto conversion? I had a recent discussion with someone who used 40MPH as his average speed to calculate the hours needed for maintenance. This would yield an equivalance of 1250 usage hours for 50,000 miles of auto life. Since many auto parts including belts have a recommended replacement time based on miles I was tending to want to use a higher average speed to get a more conservative figure for milage to hours eauivalance. I also considered shortening the recomended time by 1/3 to 1/2 for critical components like timing belts. Your thoughts? Regards Tony Dean +++ #13435 From: "Bruce A. Frank" Subject: Re: Big engine v. little engine In the beginning with the Blanton Cogbelt redrive there was some incorrect information on the correct tension of the belt. Blanton corrected the spec later, but there were other factors. The back plate, the one that bolts to the engine , gets hotter than the front or outboard plate. This sometimes causes the belt to walk on the sprocket; far enough to fray the edge of the belt. Attempts to adjust the belt many times raised the prop end of the sprocket further tightening the belt, but controlling the centering of the belt. Blanton gave specs for adjusting the belt tension when the PSRU was cold then later suggested that adjustments be made when the unit was hot from operation. Turns out that the small amount of slack allowed when the PSRU was cold made it way too tight when everything warmed up and expanded. It became obvious that a lot more slack was allowable and necessary. Most setups that I have seen that cause no problems have an inch or more movement when you push on the middle of the belt. This translates to two to three inches of the travel of the prop blade tip when everything is cold. There should still be a inch or more of movement when the PSRU is fully warmed up during operation. It would actually take a heck of a lot of slack to allow the cog teeth to disengage and damage the belt. The later design that Johnny, at Northwest Aero, developed eliminated this alignment and heat caused over tensioning problem completely by doing away with the prop shaft bearing mounted in the rear plate. The NWA design created a housing on the outside of the outboard PSRU plate. There were mounted two opposed tapered roller bearings which locked the prop shaft solidly into the outboard plate. This made the prop shaft pulley cantilevered so expansion of the rear plate had no effect on the pulley alignment. NWA also made changes in the lower outboard bearing; the bearing that supported the outboard end of the crankshaft pulley. Rather than the ball bearing that the earlier design used NWA changed it to a roller bearing. This change made the lower sprocket easier to fit by eliminating the thrust endplay detail work required with the ball bearing. The careful fit required to eliminate runout (the wobble caused by the sprocket no being perfectly aligned with the crank shaft) is still necessary and must be .0002" or less to eliminate flexing of the crankshaft. A properly fit belt, not overly tight, helps survival of the crank. The overly tight cog belt also causes rapid wear of the upper half of the engine's rear main. Both Blanton's and NWA's unit use the 4.5 inch wide belt. NWA also switched from 1/2" front and rear plates made from 6061 aluminum to 3/8" 7000 series aluminum, a much stiffer and higher strength alloy, which combined with other changes saving nearly 35 lbs. Mike Hirschfield's design uses a cogbelt only 1.5 inches wide running on a crank shaft pulley with no outboard end support. The prop shaft is cantilevered off the rear, inboard, plate. There is no outboard plate (more weight savings) Mike's proven theory is that with such a short sprocket there is no need of the outboard bearing support. Mike has flown this engine in his float plane using a nitrous system to get out of high altitude lakes. His cog belt PSRU has taken the abuse with no wear or problems. No wear on the engine's rear main bearing. Mike's belt has about 1 inch of play cold. Mike still sells units for the 3.8L Ford V-6. The cog belt running on a properly machined sprocket requires very little tension for the teeth to stay fully engaged and transfer power. A too tight belt typically makes a rather loud singing sound. Some adjust their belts tightly then back off until the singing stops. My observation is that this is still a very tight (too tight) belt. Bruce A. Frank +++ #13436 From: "Bruce A. Frank" Subject: Re: Big engine v. little engine I didn't finish answering your question. I think that belt life is reasonable for accessories, but I like a two year limit also. The serpintine belts used on the Fords to drive the alternator and water pumps get pretty heavily flexed and are under relatively high tension. The 4.5"cogbelt, heavily over built for our application, really only deteriorates from exposure to UV light. NWA recommended 500 hour replacement. Gates says their belt should go for 5000 hours. Ken Mitchel's went for the 2000 hours with no problems. Bruce A. Frank +++ #13438 From: Ken Beanlands Subject: Re: Digest Number 1045 >> Still, you can buy a half-time certified engine for about the cost >> of the properly converted auto engine, and fly it for the next 10 >> years before needing the expensive overhaul. > Where can you find that Drew? I looked for about 3 years and never > found anything reasonable. Actually, they are out there. When I started looking at engines for the Christavia, I ran into no lack of available engines, all around half time, with accessories from the aircraft salvage yards. There are half a dozen fairly good yards that I've dealt with and they typically have a good selection of 6 cylinder engines on hand from recent salvage and parted out planes. Depending on the times and conditions, you can typically talk these guys down to very reasonable prices especially on the 6-cylinder engines as there is not a lot of call for them on the experimental market. I almost bought a firewall forward 0-235 from a hail damaged C-152 that had 600 hrs TSMOH for $6500 USD back in the spring. Overhaul was done about 2 years before that. Basically, it's a matter of shopping around with the salvage yards to find what you want and then make them a reasonable offer. Ken Beanlands B.Eng (Aerospace) +++ #13441 From: "t18cox" Subject: Re: Digest Number 1045 That's also been my experience. I found 3 O540s in less than a year of keeping my eyes open. All under 1000 hrs, good logs, accesories, and $10000 or less. I bought one with 700 since a Lycoming Reman. Bill Cox #303 +++ #13439 From: Ken Beanlands Subject: Re: Re: propeller tip speed Keep in mind that most aircraft propellors spend very close to 0% of the time producing static thrust. Most of the time the props are producing thrust while moving through air. Although the 185 probably will perform better with an MT propellor, simply comparing static thrust doesn't give the full picture. There is a mistaken belief that you can stick any old CS prop on teh front of an engine ad it will just adjust to give the best performance. This is not the case. Different prop blase designs will perform at different efficiencies depending on what speed they are travelling at. Typically, you will give up either cruise performance or take-off/climb performance as a compromise to propellor design. There was a very good article that came out about 1-2 years ago covering the design of the CS prop. I have not yet received my NP, but do they give any relative performance numbers for climb and cruise? Ken Beanlands B.Eng (Aerospace) +++ #13440 From: "rodsmith52" Subject: Re: propeller tip speed Yes of course you are right Ken, blade design and chord width are a huge part of the equation. I would think though that static thrust would be a good indicator of how a prop is going to perform in getting your floatplane out of the hole and up on step. By that time another prop might perform better. No climb or cruise numbers were given in the article but it was part 1 of 2 parts. Do you recall where you read the article you referred to? Rod Smith #246 +++ #13441 From: Ken Beanlands Subject: Re: Re: propeller tip speed I was hoping you wouldn't ask that ;-). It was either in Kitplanes, Custom Planes or SA. I would suggest that static thrust is a good indication of engine performance but not that of prop performance. All of the prop charts I've seen plot efficiency against airspeed. Some peak at very low airspeeds and others at high airspeeds. Static thrust may provide a starting point, but you may also find that the 10% gain in thrust at 0 airspeed is offset by a 5% decrease in thrust at 80 mph (C-180/180 climb steed). At an extreme, a prop may have good thrust at the low airspeeds, allowing you to get off the water, but then die off while you try to clear that 50' obstical. Ken Beanlands B.Eng (Aerospace) +++ #13451 From: "Tony Snow" Subject: Re: Big engine v. little engine Another thing to consider for an auto conversion: What do you want? We talk about maintenence, initial costs, overhauls, reliability, availability, dependability, and all the other factors that can influence your decision, but one question we don't ask is: What do we want? Why are you building a BearHawk? Maybe it's just to have the most kick-ass bush plane available, but maybe it's also the challenge of learning and creating; taking pride in your accomplishments, your progress, and your craftsmanship. I think that one really big factor in auto conversions is that some of us (I see myself in this category some day when finances are more in line with my ambitions) see it as a chance to create something - to have something unusual (exactly the same motivation as the BearHawk), and to practice our abilities as problem solvers / amature (thank God) engineers. There are lots of "experts" out there - enough to get any answer you want to hear. And there are lots of right answers. When it comes to the most important question, safety, it is up to you... I have seen flying trash that I would not put myself or my family in. Ask yourself if you are willing to risk the safety of your wife in whatever you fly. Then decide. I am biased, I like the Mazda 13B conversion. Sorry, guys, I seem to have done it again. Somebody stop me before I hurt myself. Tony (Still waiting, and wondering aloud) Snow +++ #13454 From: "Montee, Dan L." Subject: Engines Yesterday I was surfing the Kitplane Radio web site that Budd will be starring on Thursday. In the archives is an interview with Dave Atkins of Atkins Rotary Specialties. Anyone interested in a wankel may want to listen in. I'm leaning heavily towards the 540 for starters. I am interested in the rotary auto conversion but I consider that my next project once the BH is in the air. Nice thing about the 540, it probably will not loose value even after using it for a few hundred hours. That is a plus over the auto conversions. Dan Montee # 415 Planter Bob, I strongly suspect your cold start problems are related to the relatively weak mag ignition system. Convert those mags to one of the "hot start" ignition systems and I'll bet your problem will disappear. Have you considered using the 13B in the skiff? Hook it up to a stern drive! +++ #13465 From: Ken Beanlands Subject: Firewall forming. I'm just about ready to pick back up where I left off on the firewall forming (that would be the firewall between the cabin and engine, not between my AS-400 and the outside world ;-). At this point I have built the form (basically a slightly flattened circle) for the Christavia firewall and I'm getting ready to bend it. Keep in mind that I'm new to the metal forming game. I would like to validate my process to see if I've got it right. 1. Mark where I plan to have the rivets/crimps 2. Notch the form so that the crimped flanges can lie flat 3. Bolt the material into the form (3/4" ply). Almost 0 springback and bend radius for 0.018" Stainless Steel. 4. Start tapping down the flanges until they become wavey (30*-45*) 5. Remove the firewall from the form 6. Crimp the flange in the pre-marked places 7. Reinstall the firewall back into the form 8. Continue tapping down the flange 9. Repeat 5-8 as required to finish the flange. If I have missed something or if this plan is flawed. please let me know. Ken Beanlands B.Eng (Aerospace) +++ #13476 From: Drew Schumann Subject: Rolling your own (engine-wise) My history so far, in homebuilt aviation, has consisted of enthusiasm for auto-conversion engines and near disdain for the certified engines, which has been tempered by consistently finding things like to write-up on Atkins' Wankel page, which tells about how wonderful the 13B mazda engine is as an aero-conversion engine. Then it ends with a glib note: "Despite repeatedly examining the engine for oil-related problems, the builder experienced a catastrophic, long-term lubrication-based engine failure and has now rebuilt the aircraft with a Franklin engine." My confidence level has just plummeted. The NTSB reports mentioned eaten valves and valve guides, several PSRU failures, one or two crank failures due to side-loads and several accessories just decide to fall off the engine failures. I won't go gather them, cause I don't have them time. Like I said earlier, I'd like nothing more than to build my own 150-200 hp auto-conversion engine for a reasonable price. I'd like to find a design and build my own engine and PSRU combination. The problem is, I'm at a point where money is very key. If there is an affordable way to get 4 people in the air, and expect them to come back down at the planned location safely, I'd try it. I have a friend who really likes SubieLyc. I've replaced their motto of "Subarus as reliable as Lycomings" with "Used, unrebuilt car engine conversions that cost EXACTLY as much as a factory rebuilt Lycoming." Frankly, there is more of that kind of uneconomic nonsense going around the homebuilt community than you'd think. I'm serious, here. I've looked and haven't been able to work it out. Perhaps someone with better research skills can show me up ;^) Drew +++ #13482 From: jdug@p... Subject: RE: Digest Number 1047 Does the rotary with, presumably a planatary reduction reverse the direction of the prop? If so, would one have to offset the tail fin the opposite way? New year greetings from NZ John +++ #13483 From: "Teresa Norton" Subject: Re: [Bearhawk] Rolling your own (engine-wise) I have riden in Ken Welters Mazda powered Coot (without the added snow machine engine) and it performs very well. As a matter of fact, I have his old rotory engine and one of the redrives that Ken builds to install on my airplane. When we stop to get fuel, he just adds some 2 cycle oil to the tank and fills up with fuel. This has worked very well and he has many many hours on it. The problems that he did have were planetary type redrive related and now he builds cog belt redrives to eliminate those problems. Arnold Teresa Norton +++ #13491 From: "Tim" Subject: 13B redrive rotation > Does the rotary with, presumably a planetary reduction reverse the > direction of the prop? If so, would one have to offset the tail fin > the opposite way? The 2.17 reverses the direction and the 2.85 the direction remains the same. Ken Welter Http://homepage.mac.com/rotarycoot/ +++ #13650 From: "Tim" Subject: Mazda 13B Rotation> Bearhawk Redrive suggestion On the 2.85 the ring gear is held solid to the case and the planet rotates and on the 2.17 the ring rotates and the planet is held solid. For the Bearhawk I would suggest the 2.85 and I forgot there is a 3.17 also, its rotation remains the same just like the 2.85. The 3.17 is the one that I used when I had the Ross redrive and I liked that ratio and the cog belt that I am running and Arnold has on his coot is a 2.95. I tried running a 2.25 and it didn't have enough static thrust to get it out of the water, that's why I would suggest 2.85 or the 3.17 over the 2.17 as the Bearhawk also needs brut static thrust. Ken +++ #13656 From: "Tim" Subject: Re: Mazda 13B Rotation> Bearhawk Redrive suggestion > I would not suggest using the planetary type redrives. I deal with > planetar gears all day and to see what one looks like after extended > use would scare the sh.. out of most people. If you want to test one > safely on the ground, drive your car around in low gear and see how > many miles you can get out of it. Arnold Agree Arnold, .....Me like Cog/Belt, vibration absorbed by the belt, none of that thar backlash concern.....Got about 250 UL hrs on them and admire the set up. 321Tim +++ #13658 From: "Bruce A. Frank" Subject: RE: Mazda 13B Rotation> Bearhawk Redrive suggestion Certainly the information I have received on the later model Ross PSRU for the Mazda engines has not been very good. The major problem seems to be quality control, but think about the rpm those small outside gears turn all the time. Tracy Crook seems to have produced a planetary drive that is durable. But I like the cogbelt designs for longevity. Bruce A. Frank +++ #13678 From: "Matt Prather" Subject: RE: Mazda 13B Rotation> Bearhawk Redrive suggestion I don't believe that planet gear arrangement necessarily is a weaker design. I am pretty certain that many of the big radials used planetary reductions (P&W 1830, 2000, 2800, 4360; Wright 1820, etc) and one of the geared Lycoming 480 engines uses a planetary reduction. Obviously they need to be properly engineered for the application. Matt Prather +++ #13693 From: "Ben" Subject: Re: Thinking automotive...Again I know it doesn't meet the criteria of the CheapHawk, but are there any opinions on the XP360. On their web site ( www.xp-360.com ), they lowered the price to around $18,999. I still don't know if the benefits justify the cost. Regards, Ben. +++ #13827 From: Tony Dean Subject: Questions about PSRU plans Seems like Blanton and possibly others sold plans to a PSRU for the amatuer builder. What ever happened to the plans built belt drives for amatuers? Bruce mentioned that some PRSU designs had problems that have since been addressed. Do any players offer plans these days? If so which are the ones recommended and which ones are not? Also why? Seems like one of the big issues was differential exmansion of the front and rear plate of the PSRU. I notice that one of the companies that offers a lower end package for Geo engines does not use the front plate and has separate front support for the top and bottom pullies. Is there anything like this for the 150HP and up builders? Regards Tony Dean +++ #13871 From: "Bruce A. Frank" Subject: Re: PSRU plans Sorry I have taken a couple of days to get back to you, but I have been looking up some of the info I have about PSRUs. Issue #20 and #22 of my newsletter cover a PSRU built by Allan Williams. It incorporates many of the best design ideas. I wanted to actually market the plans to builders, but I have never been able to get a reply from Alan's machinist partner who did most of the design work. The material in the newsletter is enough to work from with the help of a machinist or for someone able to extrapolate from expected dimensions. I do have a full set of prints of the original Blanton drive which Blanton's son, David L., no longer includes in the builders manual. Actually David D. discontinued supplying plans for the PSRU when he started building them to sell. I have written letters to David L. requesting the status of these plans; could I buy the rights to them or could I give them away. I have gotten no answer for several years of trying. I do sell a CD of all back issues for $40, which includes the above mentioned issues. The issues are available in hard copy for $7 each. The CD is a better deal as the photos are in color and detail is more visible. Russ, since a couple of other Bearhawk builders have asked similar questions I am going to post this to the group also. Bruce A. Frank +++ #13892 From: "Bruce A. Frank" Subject: Re: Re: PSRU plans > But can we get a copy of the Blanton manual??? I need one badly. > Also, where in the US are you and can you zero in my PSRU, for a fee > of course? > > Thanks, > AI Nut I am located in San Jose, CA. I talk to so many people it all runs together. Have I run through the process of getting proper runout on the crank sprocket on the Blanton drive? Have you contacted David L. Blanton about the manual? Bruce A. Frank +++ #13895 From: AINut Subject: Re: Re: PSRU plans I've talked to Dave L. Blanton's Mom, but she doesn't help with that and never did. I have tried numerous times to get Dave L. to return calls and snail mail with zero success. Guess he doesn't want to be bothered and doesn't have enough manners to say so. You gave me some a page of info awhile back about the sprocket "runout," but I didn't understand most of the terms -- my limit, not yours. I am very concerned about this. If I can fly off the hours without it breaking, maybe I can fly it out to your place for a service call? AI Nut +++ #13902 From: "Bruce A. Frank" Subject: Re: Re: PSRU plans > I have tried numerous times to get Dave L. to return calls and snail > mail with zero success. Guess he doesn't want to be bothered and > doesn't have enough manners to say so. OK, There are pictures of this process in one of the newsletter issues, but I cannot remember which number and the pictures did not reproduce well in those early days. I am going to define some terms and paint a word picture. We are trying to eliminate RUNOUT. The term as defined for this purpose is wobble in the outboard end of the crank shaft mounted sprocket. Even though the sprocket is machined very true, and the end of the crank shaft surface is also, there is enough lack of uniformity that fit up between the mounting surface on the of the crank and the mounting surface on the sprocket translated to detectable wobble on the outboard end of the sprocket. I say detectable, not visible. We are aiming for .0002", that is two ten-thousands of an inch or less. The PSRU, the back plate, must be bolted to the engine and the crank shaft sprocket bolted to the crank and torqued fully to the specs in the Ford Shop manual. You will need at least one of the side plates of the PSRU bolted in place to use as the mounting point of the dial indicator. There should be no bearing in that outboard end of the sprocket. The area into which the bearing is pressed is true (meaning without deviation) to the centerline of the sprocket and thus gives us an indication of the alignment of the crank shaft to the sprocket's centerline. To determine the runout, the amount of wobble of the outboard end of the sprocket's center line, we use a machinist's dial indicator. The dial indicator's base is attached to the side plate in such a position as to allow the dial indicator's contact point or ball (the little tiny arm that sticks off the side of the dial which when touched causes the dial hand to move around the face like the hands of a watch). The dial indicator's contact arm is adjusted to make light contact with the inside circumference of the bearing pocket in the outboard end of the sprocket. After setting the dial indicator to "0," rotate the crank shaft, preferably by using a socket with a long arm ratchet on the accessory end of the crankshaft. If you grab the flywheel to rotate the crank the pressure actually will move the crank side to side giving false readings. As the crank rotates the dial hand (needle) will move away from zero to a maximum deflection from zero then start to move back to zero as the crank makes its full 360 degrees of rotation. If that maximum deflection did not exceed .0002" your job is finished, that is after you check it ten or twelve more times. If the deflection exceeds the spec then think about which way the sprocket needs to move to reduce the wobble (deflection of the needle) , mark the high (or low) spot. Remove the sprocket from the crank shaft and sand the surface of the sprocket that mates to the end of the crank to "true" the fit. This is usually done by taking a piece of 300 to 500 grit emery paper on a very flat surface (a piece of glass works nicely) and gently sanding the contact surface to adjust the tilt. This is a slow process; not much material is removed with each stroke. The sprocket is frequently bolted back onto the crank, bolts pulled to full torque, and runout checked again. This process may take 8 to 10 hours. You may find after the first couple of tries that the runout is worse. You are learning how light or heavy a touch it takes to do the job. It will come around with careful diligence and you will not have to do it again. If you do not do it correctly the reciprocating tension on the end of the crank could break it (another good reason to keep the belt tension low) or blow out the outboard bearing. Once the runout is set the PSRU can be assembled and the plug ( the piece that fits inside the outboard bearing) located, drilled and bolted into position. Re-lubricate the bearings with about a large pea size dollop of the Mobil 28 (or equivalent ) about every 100 hours with a needle type grease nozzle slipped under the center edge of the dirt shield (actually after a while you will find that if every thing is working properly the bearings need to be lubed only every few hundred hours. I do not intend by this explanation to be too repetitive, (or condescending) but a lot of people who ask about the process have little experience with these kinds of machinery setups. One last thing, there is also endplay allowance for the crank shaft (necessary with the Blanton drive setup). That is the distance the crank moves length wise in the engine....if you push the crank as far as it will slid into the engine the pull it as far as it will slide in the other it moves about .006" to .007" (check the Ford Manual to be sure). The outboard bearing plug must not be set such that it is pressing the crank shaft into the engine. Adjustment should be about in the middle of the endplay spec. The later (and late) Northwest Aero design switched the lower bearing to a straight roller type creating no chance of binding the necessary endplay of the crank. Bruce A. Frank BTW, don't try to compensate the runout by torquing bolts on one side of the sprocket's bolt circle more or less than the bolts on the opposite side. It won't hold up. Also the material needing to be removed to make changes is usually less than the thinnest shim-stock you can find so there are no short cuts to the process. Be sure to try several different index positions of the sprocket to the crank. I have seen one that was almost .0005" out which was fixed with no additional work other than rotating the sprocket one bolt hole on the crank and retorqing the bolts. Bruce A. Frank +++ #14087 From: Tony Dean Subject: Auto conversion question You mentioned that the Soob ppl had trouble with the engines where they kept the computer and FI. What were the issues surrounding this? Which engines? Were they flying any significant hours on the planes or are we talking very early failures here? I am aware of one Soob that kept the computer but the builder tracked down all the error codes and adapted the computer to accomodate the error conditions. This took weeks if not months. Is this likely to still be trouble at 200-300 hours, or did the resolution of all error codes likely eliminate the major problems with keeping the computer? td +++ #14102 From: "Bruce A. Frank" Subject: Re: Auto conversion question Problems related to me by the Avemco were engines that received error messages either from sensors that were no longer there or sensors detecting something outside the parameters of the normal operation of the engine. Engines were going into "Limp-home" mode over the fence and the planes were crashing on takeoff. There were also some PSRU failures but mainly the engines. All of them. Bruce A. Frank +++ #14106 From: Tony Dean Subject: Re: Auto conversion question Many thinks, that limp home mode issue is one I was aware of and is particularly insidious. Sounds like the bottom line is to tkae one of two possible options: The preferred option is - Do not use the computer where it was not designed to be used. The alternative is - be sure that you understand the system and have fully adapted the computer for aviation application. td +++ #14273 From: "ken wardstrom" Subject: FULL POWER Yesterday we ran # 357 to full power for cooling tests. Got the sh*t scared out of us twice. #1 when the back end of dads car ( used to hold the plane down ) swung around to align itself with the plane, this caused the plane to lurch ahead about a foot -definatly got our attention. #2 one of the test mufflers seperated at the header connection during full power - instant big NOISE - we didn't know if we had blown the motor or blown a belt or what. Static testing at full power is hard on the nerves.Test results: 1- the ivo prop seems to be correctly sized 2- the motor water temp remained steady @ 190* 3- the return water temp remained steady @ 155* 4- the oil temp was steady @ 220* - may require some extra cooling ? 5- all air temp. sensors (7) under the cowl remained @ < 150* 6- during the emergency full power shut down the 7 sensors < 200* 7- i think good mufflers are going to be manditory, we did one full power run with open headers and jeez is it loud, it sounds just like a dammed airplane !! One of dads buddy's said it sounded beautiful-just like a merlin at full power. We may have to install a set of dump ports for the old guys. 8- While we did numerous full power runs the longest continuos run was 45 minutes. On to more testing - ken +++ #14276 From: "Bruce A. Frank" Subject: Re: FULL POWER 220 degrees for oil at a full power run of such duration is about optimum. The oil is at the right viscosity to reach every where it is supposed to go and also hot enough to eliminate any condensation the collects during cold start up and weather changes. What was your outside air temperature during this test? Bruce A. Frank +++ #14277 From: "Bruce A. Frank" Subject: Re: FULL POWER Maybe I should have hinted at just a bit more information about temperatures and viscosity here. You may know this or not . Engine oil is designed to operate best in a specific temperature range and I am not just talking about selecting the viscosity of winter or summer use. Oil that is kept too cool, according to the Shell engineer I talked with some years ago, roughly below 180 degrees F, causes increased fuel consumption due to the drag of thicker oil. Also that relatively low temp doesn't thin the oil enough to allow it to fully flow at the optimum volume through the really tight areas of an engine. Oil is designed to work best at the same temp that removes moisture. Oil doesn't have to reach 212 degrees F to boil the water out but it is a good range for both water removal and proper lubrication. Internal combustion engine oil temps as high as 260 degrees F still do their job and without breaking down or loosing lubricity. Bruce A. Frank +++ #14524 From: Budd Davisson Subject: Re: engine weight info I just got off the phone with my friends down at Texas Skyways who do the big engine conversions on 182's, including 520's and 550's. I asked them about the weights of different types of Continentals and some surprising info surfaced. The follow are the interesting weights. 0-470U 230 hp 412 # (This is the preferred model with four dampers, early ones go as low as 380 pounds) IO-470 260 hp 423# IO-520 285 hp 425 # (plus/minus 5#) IO-520 300 hp 425 # (plus/minus 10#) 0-520 280 hp 416# - he modifies IO-520s to carburetors as part of his conversions I've always been a Lycoming man and didn't pay any attention to Continentals other than seeing that they usually have more cylinder problems so I never knew any of the specifics about the engines. According to Jack Johnson, who's a real Continental-head and has been modifying them for 30 years in his Skyways operation, there's a reason the engines all cluster in the same weight range regardless of horsepower. The biggest reason is that the case and cylinder head castings are all the same where Lycoming goes to the wide deck, angle valve configuration to go to the higher horsepowers and they gain as much as 100 pounds in the process. Because the castings are all the same, Johnson is getting ready to take a bunch of 0-470U's he has taken in during conversions and is going to go to the bigger jugs and make them into 280 hp, 0-520's. I asked the obvious question, "how much" but he hasn't gotten back to me yet. This, incidentally, explains why the mount beds for all Continental mounts are the same. 'Thought y'all would enjoy knowing this. Also, I'm attaching a chart of all Continental weights you can put in your reference book bd +++ #14533 From: "rodsmith52" Subject: Re: engine weight info Do you know if these weights include accessories? The lycoming O-540 I am negotiating for shows a weight of 398# in the log book. I believe that includes the mags and carburator. Rod Smith #246 +++ #14535 From: Budd Davisson Subject: Re: Re: engine weight info I'm pretty certain this includes the accessories and the 398 for the 540 is right on the money. A good number for the weight of a traditional electrical set up (alternator/starter) is 37 pounds on a Lycoming. I don't know about a Continental. bd +++ #14920 From: Budd Davisson Subject: Re: Engine choice and insurance Bob is getting about $17K for a new Superior XP-360 engine, which is an excellent choice for this airplane. bd +++ #15033 From: charles.k.scott@d...> Subject: Re: Digest Number 1124 > Let me make this a bit more clear...... > > The gist of what I'm saying about auto conversions is that in my > simple mind I cannot see why people insist on making auto > conversions so complicated. The problem Bob, is that auto conversions tend to be complicated, if you do them yourself. Take for example just one aspect of the Ford V-6 conversion: the intake manifold. When the engine was in the truck, it sat at an angle, so Ford built the intake manifold with a slanted riser for the single point fuel injector sits to get the FI unit level. But in our installation, the engine sits level, so anything you bolt to the intake manifold is at a slant. Your choice is to install a wedged spacer plate, or machine the slant off the intake manifold. In addition, the auto intake manifold made use of EGR, and there is a big hole in the intake manifold leading to the exhaust port. This has to be covered over with a plate. So the manifold is machined flat and the plate is installed over that, then the carburator on top of that. Wait, the studs for the carburator are now slanted too, because they were installed when the intake had the slanted surface. So these threaded holes have to be filled with an aluminum epoxy and then re-threaded so that they are vertical. Now we have all those manifold openings were all those sensors went... See what I mean? Even just the intake manifold gets complicated and I haven't brought up the carburator we're using instead of the original fuel injection unit, or why this is a good idea. There are just lots and lots of dark little secrets that you must know about if you want this engine to be as reliable as it has proven to be. You can sure as heck make this engine NON reliable by ignoring all this information and forging ahead by yourself. Corky Scott +++ #15037 From: Bob Romanko Subject: RE: Engine Conversion Kits/Plans (Was: Digest Number 1 124) I appreciate the complexity of auto conversions. In no way am I saying that getting one up and running is simple. What I AM saying is that there's no need to complicate the PROCESS of documentation, parts acquisition and building. What you just briefly described in this short email to me is very clear. I understand the tasks involved, and believe I have the skills to do them. Now, take what you told me with the intake manifold modifications and expand on that to include the rest of the engine and PSRU. Get three of the BEST Ford conversion folks together and come up with it. I know, tough to get everyone to agree with everything, but it is possible to get a consensus of what a safe, reliable conversion would be. Once you do that, test the powerplant you came up with. After successful testing, document the thing to the teeth, complete with pics, drawings, part numbers, assembly techniques, etc. The only real modifications I see is radiator configuration, but like I said earlier, that's the only real difference I see. Other than cooling, the rest of the engine should be the same. From there you can sell the documentation, or heck, go as far as provide a kit. Up to you guys. I keep going back to airframes. There are a LOT of ways to screw up, let's say, designing a wing. That's why we have plans and kits. Something that was engineered, built and tested previously with a known process, parts list, and proven reliability. I still submit that if it can be done with hundreds of experimental airframes why there is this huge void of documented and tested auto conversions plans or kits? Think of it this way: How many of the guys who hang conversions on their airframes are really qualified as engineers to do so? Right. Not many. Yet they're out there gathering data and doing their best to come up with a design that works. Ok...now how about this one, how many of those SAME guys would go out and design an airframe from the ground up. Not many, right? That's my point. Most guys wouldn't think of making the claim that they have the credentials to design a fuselage, empennage, and wing, yet they somehow believe that they can design a powerplant, and we as a community of builders go along with that. It's just accepted. What I'm saying is it doesn't have to be that way, and there's no reason in my mind that someone should have to play engineer building a powerplant any more than they should play engineer designing an airframe. Sure, there are guys out there who like the thrill of surfing the Web, subscribing to egroups and lists, reading newsletters, etc. Then they go out and somehow manage to bring it all together into a package THEY believe will work, and hopefully it does. All I'm saying is this certainly seems a hit and miss approach to designing what is a critical aircraft component, and it's this very concept that has me wondering how insurance companies EVER insured conversions in the first place. The way I see insurance is for the companies it's basically a gamble. If you asked me to place a bet on a powerplant that someone I didn't know built who had no real credentials to do so, I'm not sure that I'd put the farm on it. Would you? Nope, didn't think so. Yet that's what every builder is asking an insurance company to do. One of the first things you're asked when you approach an agent is the aircraft you're building. If you told them it was something you designed you're aircraft is a total unknown, so you'll get the appropriate answer in that situation. If you say you're building an RV-6A you'd most likely be welcomed with open arms. We all understand and accept that. Why would we expect any different answer regarding powerplants? Now...if there were a way to say "My Bearhawk is powered by a Corky Scott V-6 Powerplant" and that was a known, tested, documented, accepted engine you may get a different response than saying "This is a Chevy V-6 I had laying behind the shed that my brother-in-law swapped me for a hog." Planter "Getting Back Off the Soapbox" Bob +++ #15045 From: Tony Dean Subject: Re: Engine Conversion Kits/Plans (Was: Digest Number 1 124) > Get three of the BEST Ford conversion folks together and come up > with it. I know, tough to get everyone to agree with everything, > but it is possible to get a consensus of what a safe, reliable > conversion would be. This is exactly what I want to do for each engine conversion out there. Get people who have done it, have a track record, and get the info out of their heads and into document(s). > The way I see insurance is for the companies it's basically a > gamble. If you asked me to place a bet on a powerplant that someone > I didn't know built who had no real credentials to do so, I'm not > sure that I'd put the farm on it. One thing we are seeing in the NTSB records is that the same mistakes related to installation are being made with both auto and certified powerplants. Its just that the auto crowd has an added issue of water cooling and PSRU (more complexity) that they can mess up as well. From what I hear from insurers, they have gotten much more conservative since 9/11 in all areas and this is just part of that issue. > Now...if there were a way to say "My Bearhawk is powered by a Corky > Scott V-6 Powerplant" and that was a known, tested, documented, This is exactly the idea, even where you can say "My Bearhawk is powered by a V6 built to the XYZ spec and my technical councellor checked it out (just like EAA does with airframes) you should have a better case. As a matter of fact one insurer already told me that this could make a real difference. From what I have been told they are still insuring FWF auto conversions that have lots of history at this point. Its all about risk, and if we can demonstrate that there are ways to reduce the risk, this is good for everyone involved. +++ #15066 From: Ken Beanlands Subject: Re: Re: VeedubHawk: was Engine Conversion Kits/Plans Let's see, if you used a 2100, you'd only need about 14 cylinders to get around 200 hp. Hmmm, 14/2=7, how about a 2 row, 14 cylinder radial based on VW jugs. Now, that would be COOL!!! Heck, HCI has already done a 5 cylinder radial based on VW jugs, it wouldn't be that hard to go to 14! Ken Beanlands B.Eng (Aerospace) +++ #15068 From: Tony Dean Subject: Re: Engine Conversion Kits/Plans (Was: Digest Number 1 124) You raise several good points. First, I would never expect more than the manufacturer claimed for HP and probly start a little skeptacle and mentally de-rate the engine. The exception to the is where an plan or package has been independently verified. On the failures, I keep running into people who are usually trying their own ideas and not following the plans, recommendations, or guidelines that are out there. Often not looking at people who failed at what they are attempting. For example, putting race engine parts in that were designed to last for about one race. This does not meant that all race engine parts are bad, some are very good, but it does mean you cannot take any part designed for racing and slap it in the engine and expect longevity. Some do, some don't and you have to know the difference if you start changing things inside the engine. I tend to want to start with minimum changes and improve it over time if possible. Also, what about the successes? I also keep running into people who have put hundreds and sometimes a 1-2 thousand hours on their auto conversion with little or no problems. I tend to find that they go into this with realistic ideas about weight, cost, noise, long term maintenence costs, installation issues, and their own need for education in the area. Now, how do we make their successes repeatable? Thats one of our goals! Now down to the real good part. Testing! This is an area that is often gets less attention than it should. What, exactly, is a good test strategy for an auto conversion. One thing I keep running into is people who do not check EGT and then have valve problems on a new design. Another test that is often not done is to verify that there is lower air pressure behind the cooling system than in front of it. I ran into a guy that was having cooling problems and the only change he made from the mfgr. plans was the radiator..... Could it be possible that this was the issue? He used a radiator with more cooling lines which was denser and expected better cooling. I suspect he was getting flow separation and the air was going around the radiatior at flying speeds. Its one thing to copy a successful design but if you make mods you are engineering a new engine and should test as such. Many of the succesful auto conversions I see are with pepole who did extensive ground testing and made an effort not to change too much inside the engine or at least follow a well known and well tested set of changes. Some test as many as 10 hours of taxi tests just making sure that everything worked right. How many builders skip the fuel flow testing or fly when the oil pressure is not quite right. Happens all the time and people attribute the end result of this poor teting to the auto conversion and not to the builder. Testing is an area that needs a guideline all to itself. I like your mule idea. The Raven redrive people used to put one of their GEO metro engines in the back of a GEO metro and take it out to I-25, crank up the aero engine, put the car in neutral and "Cruse". I like the test mule idea if the conversion is a new or a one off design. Should not be as necessary if you are copying another successful design. Regards Tony Dean +++ #15077 From: Del Rawlins > 't'aint no such thing as too much horse pressure. I'm more concerned about not having enough pilot, and I am not sure I want to be hanging 500 some pounds off the firewall. Since our last big discussion on engine options, I've been mulling over what to power #316 with and have come up with a few thoughts. The big lycomings and continental engines are tempting, because they would allow me to run a lower octane fuel and still be in the power range I want in the event 100ll goes away. But by the time I get finished hanging some of the other stuff on there that I want (like the auxillary tank system, etc) I am concerned that I won't have a lot of useful load left (the term "a lot" being a relative thing where the BH is concerned. Then again, I want to operate on floats, and on the water there really is no such thing as too much horsepower. So what I am thinking, is a fairly compact engine in the 200-220hp range might be a good compromise. An IO-360 lyc would be the minimum engine in this range at 200hp, but I'm really interested in the Continental IO-360 (210hp) and Franklin 6A350 (220hp) which are around the same weight, but will have the smoothness of 6 cylinders vs. only 4 with the lyc. Being longer but close to the same weight should somewhat help with balance when at or near gross. The downsides to these engines are the requirement to burn 100 octane fuel, which may or may not be available in a few years, the cost, and a cabin heat system that I consider marginal from a safety standpoint. What I think would be a perfect engine, if they can get them into production, is the Deltahawk V-4 diesel. It puts out 200hp, is in roughly the same weight range, and will likely never have a fuel availability problem within my lifetime. The liquid cooling allows for a safer cabin heat exchanger system, and no worry of shock cooling the engine. I would prefer if it made another 20 or so horsepower, but the flip side is that being turbocharged, it will make that same 200hp up to 9 or 10 thousand feet of altitude. The ATP turbine (http://www.atpcoinc.com/) is also intriguing, but like the Deltahawk it is a matter of wait and see. One big concern I have with a turbine is fuel consumption, but from looking at their figures (if they are to be believed), it isn't as bad as one might expect. As for my mission profile, I'll probably never be good enough that I can fly in and out of a strip short enough to require any more than 200-220hp on wheels, and most of my float flying will be off large lakes. The only exception will be to access some land on a lake near Cordova where Tom and I will eventually build a cabin, and that lake isn't terribly huge. The nice thing is it is less than a 10 minute flight from the seaplane base at Cordova, where there is a large lake to operate from. So conceivably if I needed to get 4 people, gear, and a cooler of meat out of the smaller lake, making a couple ferry trips to town wouldn't be a big deal, and then load up people, gear and fuel before taking off from the bigger lake, which would give me several miles to get off the water if needed. -- Del Rawlins +++ #15078 From: Budd Davisson Subject: Re: engines, again The IO-360 Lycoming would be my last choice because it's 43 pounds heavier than the 180 Lyc and they are leakers (with nearly 4,000 hours behind them I've never had a dry firewall) so a lot of your power is eaten up with weight. If you want to go with a smaller engine work on the airframe weight. A 180 with a wood, finely pitched prop would give lots of thrust, minimum weight. The IO-360 Continental and Franklin both weigh about 50 pounds more than the 180 Lyc. If you aren't going to go with a 540, go with the 180 and keep it ultra-light. Still, a 235 hp 540 is a cheap engine, put a fixed pitch prop on it to save weight/cost, turn it a little faster and you'll have an airplane that'll leap off the water at the expense of cruise speed. bd +++ #15080 From: Del Rawlins Subject: Re: engines, again > Still, a 235 hp 540 is a cheap engine, put a fixed pitch prop on it > to save weight/cost, turn it a little faster and you'll have an > airplane that'll leap off the water at the expense of cruise speed. Thanks for more to think about. I wasn't really interested in the lyc IO-360 anyway, but included it since it was in the same hp range. In my mental figuring, I was also planning on a constant speed prop, which would be required to get the performance I want out of the smaller engines. A big 540 with a fixed pitch metal prop might be a good way to go, since it isn't like I'm in a big hurry to get anywhere. I could always switch to a cruise prop if I wanted to make any long trips on wheels. -- Del Rawlins +++ #15081 From: Del Rawlins Subject: exhaust heating Is there anything that can be done to reduce the chances of a muffler cracking and letting CO into the cabin heat system, other than just inspecting the hell out of it? I ask because my brother installed an exhaust on his Citabria that was overhauled by a reputable shop, and it cracked within 50 hours. Obviously a CO detector is a must, but when (not if) it cracks, I may be off in the middle of BFE with no means to repair it. -- Del Rawlins +++ #15083 From: Benton Holzwarth Subject: Re: Engines, again I keep thinking an O-470 w/ CS is going to be the sweet spot in terms of cost (but not weight) at that power range. And in your neck of the woods, there's probably a core on every mountain side. Certainly there'll be parts and shops with the know-how to work on 'em. When people ask, that's what I say I'm planning, then quickly add that I'm years from having to make a decision. Benton +++ #15084 From: Ken Beanlands Subject: Re: exhaust heating there are two ideas that can work OK. If the engine runs hot enough to need an oil cooler, you could always yse that like a heater core to heat the plane. I'm strongly considering this route with the Franklin in the Christavia MK 1. Second, and idea I had (but have not tested in any way) would be to wrap copper or aluminum tubing around the exhaust manifolds. these would be connected to an electric pump and a heater coor and filled with anti-freeze. This could then be used to heat the cabin the same way an auto-conversion does. I'm sure that there would probably be a need for a more intense design that that, but that the principle. Ken Beanlands B.Eng (Aerospace) +++ #15085 From: Ken Beanlands Subject: Re: exhaust heating Another point here, I'm not all that concerned about a leak in the exhaust. First of all, believe it or not, they are very uncommon. We've never had on on the 180 and in talking to some of the higher time pilots I know it doesn't happen that often at all. Funny enough, this is one of the more managable problems you can have as the CO detector will warn of teh problem almost immediately if teh cabin heat is on. Then it's just a matter of closing the heat vent and opening the fresh-air vent. You now know that there is a gas leak and can address it immediately before it becomes big enough to start an engine fire. The main reason behind my using the oil cooler is because it should provide more heating than the exhaust. Ken Beanlands B.Eng (Aerospace) +++ #15090 From: "rodsmith52" Subject: Re: engines, again It seems like the 6 cyl Franklin would make a great Bearhawk engine. Its a shame that they cant seem to get their parts and service straightened out. The only other downside I have heard about that engine is the relative scarcity of CS props that fit it. Makes it hard to find a used one. Rod Smith #246 +++ #15092 From: Del Rawlins Subject: Re: engines, again > It seems like the 6 cyl Franklin would make a great Bearhawk engine. > Its a shame that they cant seem to get their parts and service > straightened out. The only other downside I have heard about that > engine is the relative scarcity of CS props that fit it. Makes it > hard to find a used one. Yep. One of my instructors has this engine on his 172 and likes it, but says that the constant speed prop is pretty much a requirement. The engine has a lot of valve overlap and doesn't make much power in the lower rpm range, so the CS prop lets it get up to max rpm much more quickly on takeoff. I realize that is what the CS prop does for any engine, but it is more important for this one. Also the compression ratio is 10.5:1 so it *needs* 100LL. Those are the reasons they are able to get 220hp out of 350 normally aspirated cubic inches at 2800 rpm. If 100LL goes away without a suitable replacement becoming available, this engine will lose a lot of its appeal (as would the Cont IO-360). An interesting factoid about Alaska that I have learned, is that the autogas STCs for certified aircraft are basically no good up here, because this is one of the states where automotive fuel is not required to meet the industry spec that is required under the STCs. -- Del Rawlins +++ #15102 From: Budd Davisson Subject: Re: exhaust heating I think it was the Bean-man who suggested anti-freeze in a coil wrapped around the exhaust stack. If that was inside a muff... Interesting idea. Does anyone still remember the gas-fired (damn, their name just fell out of my head) heaters? There was one in a 195 I rebuilt, but I never had the guts to fire it up. Of course, they also say one of those was what actually got Ricky Nelson. bd +++ #15113 From: "areyouretarded" Subject: Heating the Bearhawk, etc. Just a note to let you know that both the Prototype and the O-540 Bearhawks do not have a problem with heating. Properly warmed up - that tiny heat vent in the firewall will run you out of there. The airfoil used on the 2-seater is a Ribblet design - Since it is a lighter aiframe and has less of a useful load you don't need all the lift you get from the 4412. 4" of snow Thursday night - April 2nd can't get here to quickly. Later - Mike +++ #15114 From: Budd Davisson Subject: Re: exhaust heating >> Does anyone still remember the gas-fired (damn, their name just >> fell out of my head) heaters? > Janitrol? Something like that? As soon as I hit the "off" key it came to me: "Southwind" I think. bd +++ #15115 From: "Lee H. Erb" Subject: Re: exhaust heating > their name just fell out of my head) heaters? Irvine They were in our cars too. Lee +++ #15119 From: "Bruce A. Frank" Subject: Re: Auto-Conversion Insurance This was posted to the Christavia list. Bruce A. Frank >> EAA AIRCRAFT INSURANCE PLAN IMPROVES --- >>> Most Auto Conversions, >>> http://www.eaa.org/communications/eaanews/030207_autoengine.html >> Yes, MOST auto conversions... >> >> I just spoke with Jim Nelson @ Falcon, and here's the official >> list: >> >> Great Planes (VW) http://www.greatplainsas.com/ >> Aero Vee (VW) http://www.sonex-ltd.com/Aero_vee_2002.html >> Revmaster (VW) http://www.fortunecity.com/marina/anchor/270/rev.html >> A Sube conversion (the name brand escapes me at the moment) >> NSI (Sube) >> Powersport (Mazda) http://www.powersportaviation.com/ >> >> Any engine which bears the a brand name of a certified engine >> (Lycoming, Continental, Franklin) no mater how distorted you >> make it, high compression pistons, EFI, etc. >> >> If you have a name brand "airplane" engine, you can get >> hull coverage from day one. If you have an auto conversion > from the above list, hull insurance is available after 10 hours. >> Hapi owners are screwed, as are other conversions reputable >> conversions not on the "approved" list. +++ #15120 From: Del Rawlins Subject: Re: Heating the Bearhawk, etc. > Just a note to let you know that both the Prototype and the O-540 > Bearhawks do not have a problem with heating. Properly warmed up - > that tiny heat vent in the firewall will run you out of there. Mike, where does that tiny heat vent get its heat from? An exhaust muff or oil cooler? The whole idea of getting cabin heat off the exhaust freaks me out a little and I am looking for other opinions and ways to reduce the risk of cracks/leaks. I've also seen an example of an oil cooler that burst and I'm not sure that is the answer for cabin heat, either. Then again, the heater core on a liquid cooled engine isn't without risk, so maybe I am making a big deal out of nothing. -- Del Rawlins +++ #15122 From: Benton Holzwarth Subject: re: exhaust heating > Janitrol was more industrial oriented I think. Janitrol is the one I remember reading about in AvSafety. 8*( Benton 8feb03 +++ #15123 From: Ken Beanlands Subject: Re: Re: engines, again > It seems like the 6 cyl Franklin would make a great Bearhawk engine. Been there, done that. Would I do it again? No!! I found that there seemed to be too much petty bickering between the very few companies selling the Franklins in North America. I bought the 4A-235 for teh Christavia from one reseller but the engine did not come with mount bushings, for some reason. The reseller was out of stock so I called another reseller and was pretty much told that since I had not bought the engine from him, he would not sell me the parts I needed. Eventually, I went to the factory in Poland and had them ship the parts directly. They were prompt and provided excellent service, but the $361 USD worth of parts (small 12" x 6" x 6" box around 10 lbs) cost me $180 in shipping!!! Obviously, I now have everything I need to finish the engine installation so I will install it, but if I had my time back, I would have bought a new Rotax 912S or a rebuilt O-200 or O-235. Ken Beanlands B.Eng (Aerospace) +++ #15130 From: "Bruce A. Frank" Subject: Heating This is an interesting topic. Let me ramble a bit. In the V-6 STOL setup with the water cooled engine obviously there is not much problem with coming up with a heating system. There is more than abundant coolant to provide heat for the cabin. The idea of using the oil cooler to provide the heating for the cabin is not a bad idea and has worked in some applications before. What I question is with the size of the Bearhawk cabin verses the btu's available at the flow rates of oil through the cooling radiator. I have not been lucky enough to ride in a Bearhawk yet but several 4 place planes of similar size, 2+2 Sportsman, Maule 7 and so on, seem to have somewhat drafty cabins...enough to offset the heater significantly in very cold weather. There is certainly a proven worry about heat muffs around exhaust pipes. Though to me the solution would be to create a fully enclosed (welded together) muff, one that contacted the exhaust pipe, wrapped around it, but provided no opening that allowed gasses from a cracked stack to reach the air going to the cabin. There is also a worry about having oil routed into the cabin. Again, at least to me, fixed by leaving the oil cooling radiator in the engine compartment and just ducting the heated air to the cabin with a couple of bends to prevent hot oil from making it to the cabin if the oil radiator sprang a leak. The firewall passage way is equipped with a slide valve to completely eliminate air flow to the cabin is something goes wrong. When the cabin doesn't need the heat the heat duct is built with a flap valve that dumps back into the low pressure side of the cowling. A similar thing might be advisable even with an engine coolant cabin heater system. Place the heater core in the engine compartment and duct dedicated intake air through the core, then duct the heated air to the firewall through a slide valve into a distribution nozzles. I offer this because I have had coolant heater cores split a seam in a car. The dump of vapor, both the water and the glycol, made it difficult to drive without opening the window. Now most aircraft installed coolant heaters have a valve in the coolant lines to the core, but a split seam will dump a lot of coolant into the cabin, the core's volume, even when the coolant valve is closed quickly. With the core located in the engine compartment, the firewall slide valve would provide very quick exclusion of steam from the cockpit, the coolant line valves could then be closed to prevent loss of coolant overboard. Just some thoughts. Bruce A. Frank +++ #15134 From: "John" Subject: Re: Heating > The idea of using the oil cooler to provide the heating for the > cabin is not a bad idea and has worked in some applications before.. I'm not sure that you would even get much heat out of the oil cooler in the winter. We were flying the T-Cub the other day and couldn't get the oil temps above 120 degrees. Evidently the thermal bypass valve isn't working. We taped up the oil cooler real good and finally got the oil temps up to 160 after a good long flight. Of course thats a 150 Hp 0320, maybe the bigger engines make more heat. In my truck with a 160 degree thermostat, the heat is lousy. a 180 or 190 degree thermostat works much better. I just bought a heated jacket and gloves for the motorcycle. At 7 amps draw, it keeps you nice and toasty. I can't wait to try it in the plane. It has NO heat..... John Kozak, #511 +++ #15135 From: Alan Nauman Subject: Re: Engine Conversion Kits/Plans (Was: Digest Number 1124) I think you missed my point. I believe that the bulk of the engine failures can be found through putting it in a car. While you are not going to have the load on the engine that you would have in the air, you will find short falls of the engine such as oil pressure that is not sustained, or a cavatating water pump. The biggest reason I say that a auto engine conversion should be tested in a car first is the installation itself. There are a lot of little oversights that can happen when you start modifying engines. There are really basic things like having an balanced carb/intake/cam/exhaust combination. Is all of your custom wiring right? Do you have some goofy vacuum leaks? If you can't get it to run right in a test bed auto, then you are crazy to try to debug it in the air. The airboat idea might be OK, but I doubt you are going to find may places where yo could open it up for a couple of hours. I suppose you might be able to find a big lake and then just go in circles for a couple of hours. Here's another spin on things that I don't think has been discussed here. If an engine is designed it use EFI and electronic ignition, Isn't the simplest thing to do just to use the supplied parts? Are there not a lot of problems generated by taking a late model engine and degenerating it back to 1965 standards with a carb and points/magnetos? I don't know. I just hate getting into a certified 172 and saying 'come on baby start'. I've never had a car that would not start for a couple weeks because the temperature got down around freezing. I did have a 70 Camaro(older than the plane I am hoping will start) that I started and drove at 35 below without any heaters just to prove that it would run. Alan +++ #15137 From: Tony Dean Subject: Re: Engine Conversion Kits/Plans (Was: Digest Number 1124) I get the feeling you are talking about more than using the engin in the car but in a way that simulates an aviation condition as closely as possible. For Example, next week I have a 1000 Mi road trip planned. If possible, I would love to have my engine ready and attached to my van in an aircraft configuration, prop, cooling, cowling, and all. In an ideal situation, I should have the FWF bolted in a configuration that will simulate pulling my aircraft. Keep in mind that a clunker may need the aircraft engine extra boot just to get up to highway speeds. Once up and running, I crank up the aircraft engine, put the vehicle in neutral and cruse for extended periods of time. Is this what you mean by a test mule? I also assume that your testing is based on the idea of a custom one of a kind engine configuration and not a FWF, Kit, or proven plans constructed configuration? Regards Tony Dean +++ #15138 From: Tony Dean Subject: Re: Auto-Conversion Insurance From this list I can see that some missing players are, Belted Air Power, Northwest Aero, all Ford V6, Real World Solutions, Atkins ... Where do I even start, they left 99% of the entire auto conversion and alternative engine industry! We have about six FWF packages, no kits, no plans built, no copies of working and proven implementations, and no room for engine experimenters in the experimantal aircraft fleet. Looks like they shut down support for auto conversions, waited 30 days and advertised a much reduced level of support as if it were a major service enhancement. td +++ #15145 From: AINut Subject: Re: Contact magazine, was Engine choice and insurance Contact has changed hands. The new owner says the focus of the magazine will change but will still have auto engines once in a while. Also, you can now opt to have the issues emailed to you sometime in the future. I signed up for another year just in case it stays relevant. AI Nut +++ #15155 From: "Dan Montee" Subject: Re: Heating Glad to see you address the safety issues. Oil in particular presents unique problems. Oil pressure is considerable higher than anything the water system can develop. The oil pump is capable of even more pressure since it operates with a bypass valve to keep the pressure within limits. A failure of the system (stuck bypass valve) will raise the pressure and blow the weak link it the system. That is the cooler. Nothing like a 250 degree foot warmer! Auto racing rules makers won't allow the oil cooler exhaust air to exit into the cockpit for that reason. I know, I got my own rule in 1989 from the SCCA. I was using the cooling exhaust air to pressurize the open cockpit (normally a negative pressure area) to improve aerodynamics. Remember this is Redneck Engineering, Cut and Try Division, so I can't say if it worked or not but we did have the fastest straight line car in the class. Dan Montee 415 +++ #15157 From: Budd Davisson Subject: Re: Heating/mufflers I think we're complicating this heating issue. We worry constantly about the CO problem with a heater muff which, in this application, has a continuous piece of (usually) stainless tubing running through it. To get CO in that situation requires the stack pipe to split inside of the muff in the straight section. I'll bet I've dropped a half dozen stacks off of airplanes but every one has been at a weld at the top. Not once have I seen the straight portion split. I suppose it's possible, but I've never seen it. Some airplanes have a muff around their mufflers which do tend to crack and are sources of CO. Which brings up another question: are any of the flying BH's equipped with mufflers? It certainly needs them. We haven't gotten to that point yet, but we've had preliminary discussions with an exhaust manufacturer about making muffled systems for BH's available. The airplane is really noisy without mufflers but noise-canceling headsets don't weigh or complicate anything and mufflers do. Let's see a show of hands: how many would spring for a muffler system if it was available. bd +++ #15159 From: Russ and Penny Erb Subject: RE: Heating/mufflers Bill Johnson put a muffler in his. I'm definitely interested in putting a muffler of some sort in #164. Yes, headsets address the hearing loss problem, but they don't address another issue--sitting in a high noise environment, even with hearing protection, is fatiguing. I know from experience (too many times). Add that to mild hypoxia (flying near 10000 feet) and you're wiped out at the end of the day. (As a side note, it is possible to have so much noise that it overwhelms the headsets capability to cancel it...and then things get really weird. Been there in a Grumman Albatross, and been told it happens in a T-6 too.) I presume you will need to have a system available for (I)O-360s, (I)O-540s, and O-470s. The challenge seems to be getting the muffler in without greatly distorting the shape of the cowling. Russ "noise activist" Erb +++ #15160 From: Budd Davisson Subject: Re: Heating/mufflers > The challenge seems to be getting the muffler in without greatly > distorting the shape of the cowling. I don't know what the problems will be because we haven't looked at them. That'll be the exhaust guy's job, because we won't be offering them directly (I don't think). There may be some motor mount issues too. We just don't know. As for noise and ANRs. I once had to call a communications emergency and land with a light gun because a student's high-tech ("I can't fly without mine, it's so much better than yours and you should try one too") head set was practically destroyed in the Pitts. 125-130 db on takeoff, 95 db in cruise. A straight-stacked 540 w/o sound deadening in the firewall/floor is fierce! Pat F. do you have sound deadening and does it help? bd +++ #15165 From: "Bruce A. Frank" Subject: Sound Regulation (Was: Heating/mufflers) There is a lot of movement here in CA to drastically restrict aviation noise. Reed Hillview airport here in San Jose is coming under attention for proposed noise regulation that could be so severe that the airport could not continue to exist. When engine noise is very noticeable it makes bad neighbors. It doesn't have to be noise just around the airport. If we don't do our best to cut irritating noise they will shut us down just like they have so many airports. Airports will continue to go the way of the race track. Straight pipes are not just detrimental to your flying experience, but to those living under the departure corridor. And those non aviators call their politicians. Nobody cares that the airport has been there for 75 years and the subdivision has been there for only 6. They will still shut you down. Bruce A. Frank +++ #15166 From: bearhwk272@a... Subject: Re: Mufflers When I make it to the end of this building pipeline I fully plan on having mufflers on the end of the tuned exhaust system ( Hint). I am using an I0-470 Continental and plan on having the most pitch, slowest turning, smallest dia prop that I can get to absorb the 250 HP. The more care that you put into efficency and not creating situations where you turn power in to noise the better off you will be. Kevin +++ #15167 From: Tony Dean Subject: Re: Sound Regulation (Was: Heating/mufflers) Tell me about it. I just went to the City Council meeting and thought I had stepped into the twilight zone. Here were dozens of people complaining about how the airport was destroying their quality of life. Many who had just moved here and signed the paper that said they acknoledge that they were moving into an airport influence zone. The airport has been there since 1927 but the noise is increasingly an issue. The legitimate side of their argument was that the airposrt is growing and getting noiser all the time. We also see more ultralight activity and that is lower and noiser than GA. It is not unreasonable for people living under the influence zone to ask for less noisy aircraft. not is it unreasonable to ask that the planes be as quiet as possible. The part that will be difficult to deal with is prop noise which can be pretty loud too. Regards Tony Dean +++ #15170 From: "Bruce A. Frank" Subject: Why is a Carb Better than FI It is better, we convert to a carb on the Fords, only because it is simple. When you break a trace in the circuit of the throttle body controller with a hard landing up by the Tok River you may not make it out. Carbs are rugged, simple to understand, easy to fix such that a normal tool kit will do most of the work if repair is needed. Tests have shown that the hp differences between carb and FI is 10% or less. Contrary to what many think carbs function at virtually all angles and attitudes you'll see in an plane. The only failure to function occurs in extended inverted flight. Now a high quality mechanical FI system is excellent, if you can afford it. Bruce A. Frank +++ #15175 From: Pat Fagan Subject: Re: Heating/mufflers I had planned to install a muffler, in fact I thought they were required. My tech counselor/friend was the first to suggest going with straight pipes for weight/power. I must say I was surprised at how quite Proto 2 sounded with no muffler, which got me to thinking along the same lines. I went with straight pipes and have been happy with the result. A friend took some short video clips of #232 the other day. The first was of a take-off where he was standing about 20 feet off the runway as I went by. The other was a low speed pass. In both, the noise was quite low, and yet you can hear a dirtbike in the background at easily twice the volume. Besides,I can climb out so steeply that I really doubt I am any noisier than a muffled spam can. I'm sure I am generating much more noise with the propellor. That said, I wouldn't think of flying without hearing protection as the cockpit environment for every airplane I have ever flown, muffled or not, is too noisy for my tastes. I put a sound deadening blanket on the cockpit side of the firewall and some sound deadening material on the tunnel behind the firewall. I had plans for some on the boot cowl and under the floor, but after my weighing, I decided better headsets was a smarter idea. Putting a muffler on an O360 is probably doable, but fitting one on a carbureted O-540 would be a real challenge. Keeping the heat muff inside the cowling instead of protruding out the tunnel only allowed about 7 inches of muff on each tail pipe. It's nothing new, but it bears repeating, you can't imagine how rapidly all these little "nice to haves" add up to some serious weight gain. I don't think I went overboard and yet I'm at 1480 empty. With full fuel in the standard tanks ( I still haven't verified my tank capacity with a meter since I can't buy gas at my home airport) and passengers I can't carry the typical 100 lbs of baggage. Auxillary fuel, sound proofing, mufflers, and IFR panels are going to put a serious dent in your useful load. Pat (20 hrs) Fagan +++ #15177 From: "ken wardstrom" Subject: muffler testing We have just spent the last 4 days testing mufflers on B/H #357 with the rover v8 and this is what we did and what we discovered : - open exhausts are too damm loud - standard round auto mufflers are quiet but too big,too heavey and created 10 psi back pressure. - 4" glasspack type super trapps with 6 discs were also quite and 10 psi backpressure, 12 discs were noisey -also high priced and weigh 7 lbs. each - ford tractor mufflers ( stanley muffler co. ) are homebuilder priced ( cheap ) @ $8.00 each and lightweight @ 3lbs. each. They are 3.25 " o.d. and abuot 14" long and fit into the air outlet duct quite nicely.As dad says " for $8 each i believe they fit my plane better than the $179 supertrapps ". When we first installed then they were quite noisey so we installed a 1" o.d. crossover tube and they got really quite and less than 3 psi. backpressure. We also tried a 1.5 " crossover but the noise came back. The exhaust now has a nice throaty sound at idle, gets quiter as the revs come up, and at full throttle is still much quiter than the prop. At 75% power dad can still hear the electric fuel pump and the defroster blower motor. We also tried a water wetter additive in the cooling system and saw the return water temp drop by 25* f - ken +++ #15179 From: sonny cilley Subject: Re: Digest Number 1132 Hi Bud, I to can be put on the list for wanting to do a muffler system on my BH. here in Vt. there seems to be a heavy load of tree huggers that moved in and want the silence of the 1800's.. if they moved back where they came from it would be alot more silent.Vt. has become an odd place in resent yrs. Sonny # 234 +++ #15180 From: charles.k.scott@d... Subject: Re: Digest Number 1127 > The primary reasons are lack of power and failures. Lack of power > is most likely a problem related to engine choice. People seem to > think... If I remove all of the smog stuff, I will get a couple more > HP and it will be in line with xxx. Don't count on it. If you > really want to know what HP an auto engine is putting out, take it > in the car and have it put on a dyno. That will give you a > realistic number instead of the published number. If you have an aircraft engine that makes 180 hp and an auto engine that also makes 180 hp, and has a reduction unit to spin the prop at the same rpm, the prop doesn't care and neither does the airframe. The auto conversion just might show a few knots extra speed at cruise due to less cooling drag, but maybe not. The problem is that people are putting engines together and then flying them without knowing exactly how much power the engines are actually producing. You can guestimate by comparing performances, but to me the best thing would be to take the engine to a shop that has a dynomometer and find out what it really produces. Unfortunately, to do this, you have to assemble the engine without the PSRU, because no auto machine shop is set up to handle a PSRU. Ground testing the engine is a good idea. Running the engine at it's takeoff power setting for a while would be a good test. Corky Scott +++ #15182 From: charles.k.scott@d... Subject: Re: Digest Number 1130 > Here's another spin on things that I don't think has been discussed > here. If an engine is designed it use EFI and electronic ignition, > Isn't the simplest thing to do just to use the supplied parts? Are > there not a lot of problems generated by taking a late model engine > and degenerating it back to 1965 standards with a carb and > points/magnetos? In a way, you are right, it does seem strange to be retroactively installing a carb on an engine that was built for fuel injection, and discarding the factory built electronic ignition for something put together by someone that does not perform like the factory ignitions. However, when are building an airplane, things are different from street vehicals. For instance, the cars use a single computer that controls everything, from fuel to ignition and even to the transmission in some models. It's not only expensive, it has LOTS of wires and many probes and sensors that need to go with it and must work. Adapting such a creature to aviation use is not easy nor is if for the faint of heart. Technically, if you aren't an auto mechanic/computer wizard, you will be hard pressed to get the thing functioning correctly and reliably. In addition, once you do get it running, you are flying a single point failure, and a complicated one at that. The biggest difference between auto ignitions and airplane ignitions is that airplanes just don't require intantaneous individual and infinately variable timing at each spark plug. Nor does the fuel injection require it. What is required (for flight safety) is redundancy in those things that could cause a catastrophic loss of power where possible, or great simplicity. To that end, mounting a carb on the intake manifold rather than multipoint fuel injection makes things simple. The carb doesn't need electricity to function, nor does it need a dozen sensors. And once it's set up properly for the cruise configuration, it is nearly as efficient at atomizing fuel as fuel injection is, but it's a lot more simple and anyone can work on them. The ignition also does not need to be state of the art because you really only need a few things: you need to be able to retard the timing for easy starting and you need to be able to advance the timing for cruise. The distributer I have for the Ford, has a single plate on it with two electronic pickups. The plate has a spring loaded advance mechanism to allow retarding for starting and the springs move the plate ahead depending on the rpm of the engine. Each pickup goes to a seperate ignition system for full ignition redundancy: the engine will run with either with no difference in power. I don't want to have to figure out which ignition just failed, in the event, so I'll be using an MSD ignition switcher, which automatically switches in the even of a failure. That's why you see guys installing what seem to be parts from the past. Corky Scott +++ #15183 From: charles.k.scott@d... Subject: Re: Digest Number 1132 > Let's see a show of hands: how many would spring for a muffler > system if it was available. My hand is up. I've never considered using the Ford V-6 without a muffler. The Jerry Schweitzer cassette he sells shows him flying at the end of his disertation on how to build the engine, and that thing just YOWL's like a demented banshee. The paranoid public just isn't going to understand such noise. Corky Scott +++ #15185 From: "Matt Prather" Subject: Old tech auto conversions > In addition, once you do get it running, you are flying a single > point failure, and a complicated one at that. I have seen a number of people running EFI on their aircraft motors that also mount an Ellison on the mouth of the throttle body. They either slave the throttle plate on the Ellison to the EFI throttle, or wire it open. Then they leave the mixture in idle cuttoff for normal flight. If they have a failure, they turn off the EFI, advance the mixture on the Ellison and are able to fly home. Seems like a slick idea. The Ellison has a low parts count, is light weight, doesn't depend on a venturi, which would lower MP, and doesn't need much fuel pressure to function. > The biggest difference between auto ignitions and airplane ignitions > is that airplanes just don't require intantaneous individual and > infinately variable timing at each spark plug. Nor does the fuel > injection require it. It is nice to have since the volumetric efficiency of each cylinder differs, and varying the spark and mixture to each cylinder will give the longest life, best power and endurance. I agree, not necessary, if you are satisfied with 60's tech (which IS better than 40's tech). > What is required (for flight safety) is redundancy in those things > that could cause a catastrophic loss of power where possible, or > great simplicity. ... > which ignition just failed, in the event, so I'll be using an MSD > ignition switcher, which automatically switches in the even of a > failure. Do you know if the MSD box has two power leads? To actually be redundant, I'd like to see a box that has benign failure modes, and to that end, it would make sense for it to have 2 power supplies. I don't like the idea of the switcher box being the single point of failure. I'd have to guess that they (and you) have though this out. In my eyes, I think it would make as much sense to have a system with a coil per cylinder, and a seperate control box per cylinder. Adapting motorcycle tech would make this easy. I realize that this drives up parts count, but its unlikely that on a single flight you would suffer having more than one dead hole (of 6 or 8 for an auto conversion). And no switch box. > That's why you see guys installing what seem to be parts from the > past. Makes sense. However, I don't think reliability always implies low-tech. +++ #15186 From: "Shannon Spurgeon" Subject: Re: muffler testing > We have just spent the last 4 days testing mufflers on B/H > #357 noisey so we installed a 1" o.d. crossover tube and they > got really quite and less than 3 psi. backpressure. We also tried a > 1.5 " crossover but the noise came back. I believe that, like it or not, we are being forced to address the noise issue--at least we in the lower 48. Like smokers, producers of what others interpret as "loud noise" are the only groups left who (whom?) it is politically correct to discriminate against. And we just HAVE to be able to discriminate against somebody!! So, we look at mufflers, slow-turning props, anything that will appease our hypercritical neighbors, and protect our freedom to fly. So. I find the one inch crossover very interesting. Where in the exhaust stream is it located? And for you nuclear rocket surgeons, why is one inch more effective than a larger size? Guess I find this so interesting because of the inherent mysteries. Shannon +++ #15187 From: Ken Beanlands Subject: Re: Digest Number 1130 This is one area I still find rather peculiar on aircraft engines. For some reason, there is a belief that aircraft ignition systems need to be redundant, when EVERYTHING else is not. A carb is a VERY complex piece of equipment and has had a reputation of being difficult to deal with. I would suggest that there is more complexity in a carb than any ignition system. However, we still target the ignition system as being the most likely failure point. In fact, the only engine failures I've suffered in any vehicle over the past 15 years (airplane or car) have been caused by the carb on the '85 GMC Jimmy and the air temp sensor in the fuel injection on my '92 Mazda Protege. I have never experienced an ignition failure. My understanding of the dual ignition for aircraft history (maybe Lee Erb can help out here) was that it had been implimented for two reasons. Early aircraft engines (circa 1920, 1930) borrowed heavily from automotive technology of the day. As such, they suffered fairly high failure rates on ignition systems. Also, early ignition systems were not that hot. Adding a second plug greatly improved performance for a small increase in weight. We still benefit from this today as can be seen with up to a 75 rpm drop at 1500 rpm on most aircraft or up to 200 rpm at take-off power. Modern ignition systems are at least as reliable as the other critical components on the plane such as oil pumps, fuel lines, fuel pumps, carbs, cranks, rods, cylinders, oil seals, oil coolers, fuel selectors, and even pilots ;-). If I were to look at an automotive engine, I probably would not consider a dual ignition system unless there was a significant performance increase. This would not be the case with a single plug. More likely, I would buy a high performance ignition system and stick to that. Of course, since I've gone with a Franklin, and it already has the holes for the second plugs and mag (and 2 brand new Slick mags) and there is a definite performance increase with 2 plugs, this is a mute point for me. I would love to hear anyone elses thoughts on this and hear if anyone knows the history behind dual ignition. Ken Beanlands B.Eng (Aerospace) +++ #15188 From: Budd Davisson Subject: Re: muffler testing Ken's W's muffler testing has me intrigued. On the tractor mufflers, what was the ID of the inlet/outlet tubes and were they straight through? How did you measure the back pressure? On the automotive mufflers giving 10-12 psi back pressure, were they straight throughs? Does anyone know the ID of a 540 stack off hand? One of my advertising clients is an aftermarket exhaust manufacture here in Phoenix (PaceSetter) and I'm wondering if there's a source there. Also, I don't see why, with a little experimentation, we couldn't use an automotive approach to the mufflers and hang them on the end of the stacks with appropriate flex joints and suspension systems rather than complicating our lives with the aeronautical systems. I have the only airplane on the airport with straight stacks and even though it is by actual count the busiest single-runway airport in the country, I'm constantly catching crap for the amount of noise I put out (of course, I'm also visually very identifiable). I say if there is a way we can easily keep the noise down without compromising performance or complicating our lives we ought to do it. bd +++ #15191 From: Tom Marsh Subject: RE: EFI vs. Carbs Ken, what you say makes a lot of sense to me. I'm not a mechanic or an engineer but it seems to me we should take advantage of the newer, more efficient technology as long as it is reliable, which seems to be the point of contention. I have had very few problems with my Subaru vehicles for the last 18 years. I had to replace the digital clock on one to the instrument computer would work, but the engine ran just fine. I now drive a Forester with the 2.5L and its so smooth you hardly know it's running. Why should I use a gas powered vibrator with a propeller on the front. Tom (35*f, drizzling, & slick as snot in the 'frigid' north) Marsh #596 +++ #15193 From: Budd Davisson Subject: Re: muffler testing A lot of foreign aircraft have long exhaust systems running back under the airplane with a single muffler. I personally don't like those systems. I'd rather see something that stays mostly under the cowl but doesn't block much out going air. bd +++ #15194 From: Ken Beanlands Subject: Re: muffler testing There was an article last year in Custom Planes about the use of automotive muffs on a Tailwind. teh end result was more power than the original strait pipes and a lot quieter. There was a weight penalty, f course. Ken Beanlands B.Eng (Aerospace) +++ #15195 From: Budd Davisson Subject: Re: 540 stack/muffler testing Somebody cough up the OD of a 540 stack and I'll see what straight-through muffs are being manufactured by my client, toss them on a scale and report back. How long is it going to be before we're forced to hang cat converters on them too? bd +++ #15198 From: Del Rawlins Subject: RE: EFI vs. Carbs > I now drive a Forester with the 2.5L and its so smooth you hardly > know it's running. Why should I use a gas powered vibrator with a > propeller on the front. As much as I like EFI on my ground vehicles, I'm not so sure I want it on my airplane just yet. Last fall my 2001 Jeep left me stranded at mile 87 on the parks highway when the fuel injection abruptly ceased to function. Luckily i happened there, and not two days before when I was deep inside Canada. Cell phone coverage was just good enough to summon a tow to the dealership (under warranty, so I didn't have to pay for it). The dealer here had it for a few days, and all indications were of a black box failure according to the trouble codes. When the first thing he tried didn't work, the technician became suspicious and delved a little deeper. As it so happened, the drive for the "camshaft position sensor" had seized up, and the bad signal had shut the entire injection and ignition system down. Luckily for me this guy had his act together and found it right away, because many mechanics might have thrown parts at it for weeks and never found the root cause. Granted, this was pure mechanical failure, not electronic, but the point is that the more sensors and widgets you hang off an engine the more things can possibly go wrong. There are several more such position (crankshaft, throttle, etc) sensors on that engine, and the loss of any of them can shut it down. Don't get me wrong, I LOVE my fuel injection, especially on a cold morning, or climbing off road at some odd angle which would give a float carb trouble, but I'm not ready to fly behind it yet. -- Del Rawlins +++ #15199 From: "Lee H. Erb" Subject: RE: EFI vs. Carbs and ignitions > they suffered fairly high failure rates on ignition systems. Also, > early ignition systems were not that hot. Adding a second plug > greatly improved performance for a small increase in weight. I'll give you what I remember from the 1940 time frame. Don't take this as gospel but this was the gossip. Both of the above are correct. The high altitude flying in 1939 era was still learning about ignition harnesses. (Spark leaks at low pressures, Shielding high voltage, insulation deterioration (weather, heat), spark plugs fouling, etc ). Magnetos would get grounded and shafts would break. The science of Metallurgy and Dynamics (vibrations) really did not advance until WWII required them. One of the apparent reasons TWA had a maintenace facility at Kansas City was that in the mid 1930's they had an engine failure on almost every transcontinental. flight (Aero Digest approx 1936). They could usually nurse a bad engine to KC (another reason for the Fokker trimoter). (When the Wright 3350 first came out in the DC-7 in the 1950's they usually had to replace one of the 4 engines.) My thinking from a design approach, was that flame propogation in the cylinders was too slow for the large diameter jugs. Wright was also using large valve overlap to get the exhaust out. As you know, valve overlap makes for rough idling. That is why P&W had more cylinders (smaller jugs) than the Wrights for the same horsepower. P&W was a little heavier but far more reliable. I assume each of you know that P&W was started by the same engineers that developed the Wright J-5 that was so reliable for Lindbergh. Their first engine was a 400 HP R-985. Years ago I got a copy of their official 25-Year history (1927 to 1952) The history of why P&W Aircraft was formed was later replicated by English Airspeed (see the book "Slide Rule"). Boards of Directors (and Government Politics) have ruined many a company and/or product. Right now I wish I could remember the name of the man that wrote "Slide Rule." It was primarily an autobiography and the story of the design of the R-100 and R-101 dirigibles and Airspeed. Once I started the book I could not put it down. There is more than you really wanted to know, but that is the danger of getting me involved. Lee H. Erb +++ #15201 From: "Mark Conover" Subject: Re: (Nevil Shute / Slide Rule) Here is a link to a summary of Shute's "Slide Rule".... http://www.freespeaker.org/technology/airshiprace.html Mark Conover, +++ #15203 From: Budd Davisson Subject: Re: Trim Tabs > A friend and I were working on the elevators this weekend and he > asked the question, "Why are there two trim tabs instead of just > one?" Anyone know? Dan Shilling Bob has been asked this before and it's because he (as do most engineers) like loads to be symmetric. bd +++ #15205 From: "Dan Montee" Subject: Neville Shute I have a quote on my office wall by Neville that embarrassingly enough I can't quote verbatim but goes something like, "a man has not lived to the fullest unless he puts his life in danger from time to time." His accounts of testing the dirigibles were my favorites. On The Beach no doubt his most well known book. Dan Montee # 415 +++ #15207 From: "Bruce A. Frank" Subject: Re: Old tech auto conversions I am not sure Corky made it clear, there are two triggers in the distributor, two separate ignition (Capacitive Discharge) modules, two separate coils, two separate batteries. This all comes together into the MSD automatic coil switcher. The Coil Switcher is sort of a misnomer. It is not a mechanical or electro-mechanical relay or "switch". It is a bundle of diodes (both series and parallel) that handles the voltage of todays CD ignitions (individual diode failures are of no consequence...there are dozens). Both coils output into the Coil Switcher. The Coil Switcher's output goes to the distributor. Both ignition systems are on at the same time so that if either ignition system fails the other continues to do its job. For full redundancy both systems are powered during takeoff and landing. Usually the builder wires each ignition system to an on/off switch on the instrument panel. This allows selection of either Left, Right, or Both. (the names "left" and "right" used for convenience ) so that the pilot may select to run one or the other ignition during flight ( in theory this saves the parts so the life of the ignition system is extended...in actuality running both continuously makes little if any difference at cruise). As for running an Ellison as back-up for electronic fuel injection, those doing that don't have a good handle on how the fuel distribution system works. If they are using the electronic fuel injection throttle body intake manifold and running the engine in a airplane, which is a steady state operation, there is little if any advantage of the electronic throttle body over the manual (Ellison) throttle body. Management of the fuel flow micro-second to micro-second, as the computer can do if the sensors are setup correctly on the engine, offers little practical advantage in the airplane. The mechanical Ellison will do the job equally to that of the EFI using throttle body. The only drawback to the Ellison is the cost. Last I checked the #5, the correct size for the Ford 3.8L, was more than $1500. My Holley cost me $200 and has taken several engines to more than 1500 trouble free hours of flight. Bruce A. Frank +++ #15209 From: "Rod Smith" Subject: Re: Re: 540 stack/muffler testing I'm pretty sure they are 1 3/4". Rod Smith #246 +++ #15210 From: "t18cox" Subject: Re: 540 stack/muffler testing Parallel valve Lycomings have 1 3/4" stacks. On 540s they often merge into a larger tube to the muffler. On a PA24 that tube is 2 1/2". There was mention of a 1" balance tube between the exhaust pipes. Some years ago there was a lot of Skybolt and Starduster activity in this area. Most everyone used a 540 and someone tried the the 1" balance tube. Before long it was considered a necessity. I had been thinking about it for my installation. I may wait so I can compare with and without the balance tube. Bill Cox #303 +++ #15211 From: "ken wardstrom" Subject: tractor mufflers Budd, the mufflers are 2" inlet and outlet staight thru with diversion louvers that direct some of the gasses out into the space between the inner and outer pipe and then back into the main flow. There is no packing material between the pipes. They did have larger 2.25 and 2.5 mufflers on the shelf. The auto mufflers were NOT straight thru, they were just standard 2" with internal baffling. The pressure tests were done with a 0-30 psi. gauge connected to the header collector, where our secondary o2 sensor is normally mounted. We also noticed a pronounced pulsing of the gauge prior to installing the 1" crossover tube. The pulsing virtually disappeared with the installation of the tube. To mount the mufflers we installed 3x2 reducers with 6" stub pipes on the header collecters, the crossover pipe is between the stub pipes, the inlets to the mufflers are mounted directly to the stub pipes and the outlet end of the mufflers are supported from the airframe using some strips of high temp. belting and some simple fabricated clamps. The mufflers have 1" clearance to the air outlet duct. We ran a full 1 hour 100% power static test and everything stayed nice and cool.-ken +++ #15215 From: Russell Bell Subject: mufflers There was a muffler called a Barnett or Barrett air muffler. Consisted of a double layer of stainless with punched holes in the outer side, looked like a cheese grater. The people selling it claimed it both quieted the engine and increased airspeed. May have been the Barnett gyroplane manufacturer. Anybody have any experience with this gadget? Russ Bell +++ #15218 From: Russ and Penny Erb Subject: RE: EFI vs. Carbs and ignitions To clarify a couple of things (since he beat me to the answer)... > The high altitude flying in 1939 era was still learning about > ignition harnesses. (Spark leaks at low pressures, Shielding high > voltage, insulation deterioration (weather, heat), spark plugs > fouling, etc ). Ignition is a problem at high altitudes because air is an insulator. The absence of air (vacuum) is effectively a conductor. We don't even think about it at the altitudes we live, but at high altitudes the air pressure is low enough that gaps that were effectively insulated at low altitudes start letting sparks jump to ground instead of going through the spark plug. This also has a LOT to do with why radar waveguides are pressurized to prevent arcing. > My thinking from a design approach, was that flame propogation in > the cylinders was too slow for the large diameter jugs. That was the point I wanted to make. Remember, Lycoming, Continental, Allison, P&W, and Wright cylinders all have a bore between 5 and 6.125 inches. Car cylinder bores are typically 3 to 4 inches. I have read in several books that one reason for dual ignition is that at typical engine speeds (RPMs), the flame front from the spark does not have enough time to cross the entire cylinder and build the pressure before the piston has moved too far down the cylinder. With 2 sparks, the flame front only has to go half as far. As I recall, the idea is to have the gas reach its maximum pressure just as the piston starts down. Once the gasses start to expand, any further burning doesn't really add anything. Thus, a big reason for dual ignition on large bore cylinders is better efficiency, not reliability (even though reliability is improved) If you can get the previously referenced history of Pratt & Whitney, it is an outstanding read. Russ Erb +++ #15223 From: charles.k.scott@d... Subject: Re: Digest Number 1134 > This is one area I still find rather peculiar on aircraft > engines. For some reason, there is a belief that aircraft ignition > systems need to be redundant, when EVERYTHING else is not. Early aircraft engines went to dual magnetos for several reasons: 1. the primary one was for redundancy as early magnetos and/or battery ignition systems were notoriously unreliable and magneto ignition was actually the more popular type with many auto manufacturers. 2. As aircraft engines increased in size, it became necessary to have the dual ignition systems in order to properly light the flame front in the combustion chamber, due to the large size of the cylinders. As to dual ignition today, what with the super reliability in auto ignition and whether it's necessary or not, you pays your money and you takes your chances. If you feel safe using a single point ignition system, then by all means use it. But even today's super reliable ignitions still fail, sad to say, and if you are flying behind one of them, it won't do any good to quote statistics of reliability when yours fails. It just makes good sense to double up on the ignition system because it's so easy to do and would prevent a catastrophic engine out. As to the complexity of the carburator vs electronic fuel injection, I guess it's a matter of relativity. The carb used on the Ford V-6 is just a two barrell and doesn't have that many parts. It does not require electricity to run nor does it require much fuel pressure and does not require any sensors to perform properly. It has a mechanical choke so it does not need air temperature sensors and various enrichening devices to cope with cold temperatures. So in this sense, it's relatively simple when compared to today's electronic fuel injection with all it's high pressure fuel pumps, individual fuel injectors, MAP sensor, temp sensor, barometric sensor, motion sensor, coolant sensor, oil pressure sensor etc. etc. All these things have to function properly for proper fuel injection. Then, the computer is also doing the ignition, which it's fully capable of handling, it's got memory to spare. But it's one single computer, loose it and you loose everything. Corky (I'll be using dual ignition) Scott +++ #15246 From: "zipppydoggg" Subject: Re: muffler testing It my memory is correct, the reference is to "Swiss" mufflers. This subject was covered in Sport Aviation several years ago (will check my EAA CDs). This was a "straight through" muffler, light weight, attached to the belly of the plane, with appropriate joints at the firewall juncture. I understand they have to have them in Europe. I guess a decrease in airsped of a couple of knots is better than no airspeed at all. Rob (BH401)Gaddy +++ #15250 From: "Brian Cox" Subject: RE: Re: muffler testing The Swiss muffler is also covered in one of Tony Bingelis' books. I have all four, but off the top of my head, can't remember which one has it. By the way, Cessna 310's, like a lot of twins, have a pair straightpipes on each engine, one at the 1-3-5 cylinders and the other at the 2-4-6 cylinders. I don't find the sound very objectionable. Max prop RPM is 2625, so that probably cuts down on noise from the 82" prop. It's much quieter on takeoff when compared to a Cessna 206/207/210/185 at 2700 RPM. Having said that, I am all in favor of keeping the noise down as much as possible to keep from offending anyone on the ground. I'm intrigued by the use of small mufflers on the end of 310 type straightpipes. Brian Cox, #478 +++ #15252 From: Shawn Harrison Subject: Re: re: Muffler Testing > It my memory is correct, the reference is to "Swiss" mufflers. Firewall Forward, ed. 1992, pp. 111-113. +++ #15255 From: "Mark Deacon" Subject: Re: Muffler Testing Check out "Ping's" web sight. http://www.piteraq.dk/map.html How to's on the Swiss mufler, exhaust system design and some other good stuff. Mark Deacon +++ #15257 From: "Bruce A. Frank" Subject: Re: Re: Muffler Testing Specifically http://www.piteraq.dk/flight/muffler.html This is interesting information. Bruce A. Frank +++ #15307 From: "Rod Smith" Subject: Re: Bit off a big chunk > It looks like I got the MP-14 sold on E-bay this morning. Now I > hope that 1 dozen roses = 1 aircraft engine. I'm finding it hard to > swallow. Now, I think I need a prop, an oil tank, an air tank, > fittings changeover, and a CAT scan. > > HELP! Kevin Kimball at www.jimkimballenterprises.com would be a big help for providing anything you need for that engine. He is very knowlegable and willing to provide advise. They are the Pitts Model 12 kit people. Rod Smith #246 +++ #15469 From: "areyouretarded" Subject: Alternator Information > I just purchased and brought home the John Deere altenator and > Voltage regulator as suggested in the BearTracks Newsletter. After I > got home, I realized that there are no wiring diagrams for either. > Has anyone else used this and figured out the wiring? Mike, can you > check with the Bob and find out if he as the wiring diagram? Here is the link for the alt. info you need. http://home.hiwaay.net/~langford/corvair/dynamo.html Thanks, Mike +++ #15499 From: "Dan Montee" Subject: engine noise While the exhaust rightly gets the bulk of attention when it comes to engine noise don't neglect the intake. SCCA invoked a 105dba at 50' rule. A competitor complained that he couldn't get under 106 with open exhaust while others were at 102 or 103. The difference was the others had K & N air filters and he was running without an air filter. Dan Montee # 415 +++ #15500 From: Russ and Penny Erb Subject: RE: Engine Thrustline > What is the best or projected thrustline for the engine. Because I > plan to use an auto engine to power my Bearhawk, I need to plan the > engine location as well as the height of the redrive (belt type of > course) It is mainly the fire wall forward arrangment I am concerned > about. Arnold Per the Jan 98 Bear-Tracks, the fuselage reference line shown on Drawing 1 and Drawing 16 is the thrust line. Russ Erb +++ #15911 From: "zipppydoggg" Subject: 6 cylinder engine CG? I've started down the road to install the M14P engine in the Bearhawk, a project the size of an elephant. I am working an a spreadsheet for comparative weights and CG locations. I am looking for the CG location of a representative 6 cylinder engine to "back it out" of the CG calculations that Bob has published in Beartracks. I can't find it in the newsgroup, CD or newsgroup archieves. Does anyone know? Also if anyone has actual wing weights (off aircraft) and weight of fuselage (at mains and tailwheel) without wings, it would be greatly appreciated. I think it would be nice to run a fuselage only weight and balance and also one with the complete aircraft. This will give addtional information about wing loads, etc. bd, I'm planing to come see you, to talk DesertHawk when I get a little more education / information. Rob "you eat an elephant one bite at a time" Gaddy +++ #15912 From: Budd Davisson Subject: Re: 6 cylinder engine CG? I can't find the file I was looking for but I seem to remember during my conversations with Bob on the same subject that the 0-540 CG was 22" from the firewall and the FWF weight is 540 pounds (that's a confirmed weight). With the shortest mount possible on the M-14 (14") which means putting the oil tank, air tank etc in the baggage compartment for CG that puts 629 pounds FWF (also confirmed), prop and all, 21" forward of the firewall. So you're 80 pounds heavier but an inch aft, so it's not that big a deal. There are some important structural mods (wing and fuselage) I'll talk to you about but the most critical ones have to do with the small distance between the landing gear attach points when you lengthen the gear a minimum of four inches and run bigger tires. I always assumed 8:50s to keep them in scale with the appearance of the airplane and for more prop clearance. This is going to make the spin-up loads going up the rear gear leg into the fuselage pretty high. The choice is to move that carryt hrough structure back or just put a bunch of steel in it. I vote for more steel. Not as efficient but to move the structure would cause lots of nightmarish changes. The smallest prop available for the Vendenyev is 94" with most being 96". The Whirlwind is the prop of choice. 1700 pounds of static trust on a 2500 pound airplane. Yeehah!!! Gimme a call, 602/971-3991. Burgers are on you :-) bd +++ #15983 From: "Bruce A. Frank" Subject: Re: diesels >My instructor likes the looks of this diesel engine: > >http://www.deltahawkengines.com/ > >Major disadvantage I see is that you need to refuel with diesel or >jetA, and not all airports carry the latter. True, but one of the advantages of diesel is the safety of transportation (regardless of what they say about empty center fuel tanks on certain airliners) and handling. Whereas one might hesitate to transport and fill their on plane's tanks with gasoline, automotive diesel or Jet A presents no such hazard. Overall, particularly in seaplane operation, diesel may be easier to find. Bruce A. Frank +++ #16012 From: John Mireley Subject: Re: [Bearhawk] Re: Aircraft Diesel This diesel has been flying awhile in England and a production unit has completed some European certification tests. http://www.wilksch.com/ +++ #16085 From: "Mark Conover" Subject: Bob's O-360 Pricing >> Does that include the core? > Yes. I wondered too, since 13k is a very good price. I asked Bob > whether he preferred to have the buyer provide the core, or not. He > replied that, in most cases, he provides the core. When I was on the phone with Bob Barrows yesterday, I asked about his price for an overhauled O-360, essentially as configured in the original Prototype. Not sure if it's been reported here before: Price: ~$13,000.00 Deposit: $100.00 Lead-in time: up to 11 months +++ #16091 From: Budd Davisson Subject: Re: Re: Bob's O-360 Pricing To clarify: this does include the core right? If so, that's a terrific price and it makes it hard to justify flying an engine that isn't overhauled. He quoted $17k for a NEW ECI 360. A factory-new 0-363 A1A from us is $22,400 w/factory warranty. bd +++ #16093 From: "Mark Conover" Subject: Re: Bob's O-360 Pricing Yep, that very good price does include the core. Mark Conover +++ #16114 From: Budd Davisson Subject: Re: Re: Bob's O-360 Pricing > Budd, ever ask pricing on Bob's 0-540 engine? With and without > supplied core? One of our guys just took delivery of one and it was $18,000 including core w/rebuilt jugs. bd +++ #16259 From: "bearhawk232" Subject: Re: Oil Coolers > Wondering what people are using or planning to use for oil coolers > on O-540 installations, brand, size etc. Pat, what are you using and > do you consider it adequate? Did you mount yours like Bob did on > Proto 2, behind the right rear clyinder? > > Rod Smith #246 Montrose, CO I used the Positech oil cooler. I went on their website to find which one is recommended for the O-540. I may have even ordered it from them as the one Spruce carried was too small, so I sent it back. During my EAA inspection, one of the tech counselors advised that Positech has had some problems with cracking and said I should have gone with another brand. Can't remember what that brand was, off hand, but Spruce carried them and they were made in Southern California. That said, my Positech doesn't appear to be leaking and it seems to be doing the job. Of course, it isn't summer yet, but oil temperatures run normally in the 120-150 range. I placed mine on the right side rear baffle, like Bob, but had to turn it around with the fittings on the inside for cowling clearance. Pat Fagan +++ #16260 From: Del Rawlins Subject: Re: Oil Coolers > That said, my Positech doesn't appear to be leaking and it seems to > be doing the job. Of course, it isn't summer yet, but oil > temperatures run normally in the 120-150 range. I placed mine on > the right side rear baffle, like Bob, but had to turn it around with > the fittings on the inside for cowling clearance. That may not be hot enough to burn off the crap that accumulates in your oil. Unless I am mistaken, 180 or so is usually considered normal. Where is your temperature sending unit located? -- Del Rawlins +++ #16277 From: "ken wardstrom" Subject: roverv8 Robert, the motor is a late 1996,wieghs 312 lbs. and cost $4500. The complete firewall forward weighs 446 lbs. , including prop and our investment so far is $15,000 and 1800 hrs. of labour. We did all our own fabricating and machining. Some things we have discovered on our journey: 1 auto-conversion will add considerable time to project(fly or build) 2 the new overhead cam motors are much heavier than pushrod motors. 3 the ford 3.8 and chev 4.3 have good power and backup knowledge 4 the bearhawk cowl is very tight for auto conversions,but had we moved our nosebowl ahead 4" we would have much more room and kept the sleek lines of the 180 prototype. - ken +++ #16279 From: "bearhawk232" Subject: Re: Oil Coolers > That may not be hot enough to burn off the crap that accumulates in > your oil. Unless I am mistaken, 180 or so is usually considered > normal. Where is your temperature sending unit located? Del, I stand corrected. I flew today and realized that normal temps I have been seeing are 150-180. I am not, and have never been, a "numbers" guy. I know what is right when I look at it, but when I sit at the computer my recall isn't that hot. So, new policy. No more numbers off the top of my head. If someone wants to know something specific, ask, and I will go find out and RIGHT IT DOWN. Budd can now relax as I will stop giving out potentially wrong figures. By the way, oil temp was at 200 after departing Rosamond today. The max I have ever seen was....can't say because I don't remember exactly (see new policy above). It is noted in my test flight log, but I didn't look it up. It was definitely below red line, (whatever that is). Pat "not a numbers guy, what kind of man are you?" Fagan +++ #16365 From: lisankejm@g...> Subject: O-470 M rotation? Does any one know whether an O-470 M is normal or reverse rotation? Any rotation info on other models would be appreciated as well. I believe Lycoming prefixes opposite rotation engines with an "L". Can any one verify this? TIA, Joe Lisanke +++ #16366 From: "Brian Cox" Subject: RE: O-470 M rotation? The rotation on the O-470M is right hand. The Type Certification Data Sheet (TCDS) is posted on the Bearhawk e-Group. Log in, click on Files in the left hand column, then select the file E-273.pdf. I had earlier downloaded the TCDS for several candidate Bearhawk engines from the FAA website and posted them on the Bearhawk e-Group. Brian Cox +++ #16369 From: "Brian Cox" Subject: RE: 0-540-L3C5 > anybody have anything that gives the weight of this engine? It's the > 235 hp wide deck and I have a base weight for the wide decks of > about 433 pounds plus electrics but need more specific information > and can't find my file on them. The TCDS for the O-540, E-273.pdf, is posted on the files section of the Bearhawk e-group. This includes data about the O-540 L3C5. You might be able to glean through it to get the info you need. For info about any specific engine, the FAA website has much data if you can go through the tedium to access it. Here's how to do it for an engine: go to www.faa.gov Under the Certification heading, click on "aircraft" Under Design Aprovals, click on "Engines, Propellers, & APUs" click on "TCDS Search" click on "By Product Type" click on "Engine" click on the subheading under Engine that reads "(No Subtype)" This will allow you to scroll through the engine types and cross reference to the TCDS. Similar process is available for Propellers and lots of other accessories. It's not the easiest info to access, but once you get to it there is a lot of helpful stuff there. Brian Cox +++ #16371 From: "t18cox" Subject: Re: 0-540-L3C5 The TCDS lists the L3C5D at 367 dry weight. Bill Cox +++ #16377 From: "t18cox" Subject: Re: 0-540-L3C5 That is one of the engines shown for the turbo skylane and the weight for the L3C5D is listed as 367 minus the starter and alternator. Bill +++ #16727 From: Budd Davisson Subject: Re: Hartzel prop > Some time ago you listed the engine and prop you have OEM on. > Naturally I've lost the info. Do you have the prop Model handy? Here's the prop/engine info. O-540 A4D5, 250 HP at 2575 RPM. $31.995 This model comes with two sixth order counterweights for use with the Hartzell "compact" series prop. Comes with: SkyTech lightweight starter, alternator, mags, carb, & engine driven fuel pump (which Bob says it doesn't need). O-360 A1A, 180 hp, similarly equipped. $22,400. Now for props: Prop For 0-540 Hartzell CS 84" 2 blade model (compact series) for O-540 #C2R00070 HC-C2YR-1RF/F8477/SM19 . $5,400. Spinner assembly for this prop is $695. Hartzell governor $2,025 Prop for O-360 (includes a dampener, $1,015 alone). A C3R00053 HC-C2YR-1BF/F8477-4/SM16. $6195. Spinner and governors fit both O-540's and O-360's. Three blade props are available, but weigh 20 lbs. more than 2-blades. Terms are 35% down at time of order, 65% due one week before ship date (Usually about 90 days after order is placed). Transportation and insurance are provided by buyer. +++ #16732 From: Budd Davisson Subject: Re: FI or not FI > What are the pros and cons of carberated vs fuel injection in the > Bearhawk. The only three draw backs I can think of are possible hot start problems, it's hard to hand prop an FI engine in case of a dead battery, and it complicates the fuel tank plumbing. bd +++ #16733 From: Russ and Penny Erb Subject: RE: Re: FI or not FI I've heard that fuel injection also requires a high pressure boost pump as a backup to the engine driven fuel pump--gravity feed is no where near enough. Can anyone confirm or deny this? The high pressure boost pumps in the Spruce Catalog ain't cheap. Russ Erb +++ #16734 From: AI Nut Subject: Re: Re: FI or not FI go to an automotive parts house and ask for the external electric fuel pump built by Masters, an E2000. Solid as a rock. I think one of the many vehicles it fits is an '89 F150. About $60. HTH, AI Nut +++ #16735 From: "rodsmith52" Subject: Re: FI or not FI That is true Russ. Also you need to have a high pressure engine driven pump, carburated engines come with a low pressure pump. Now for the benefits. If set up properly much better fuel distribution to each cylinder. If combined with 6 cyl egt the engine can be agressively leaned for a significant fuel savings. Airflow Performance's setup pretty much eliminates hot start problems. You turn on the boost pump and open a solenoid valve that pumps cool fuel from the tanks through the system, removing any trapped vapor. +++ #17024 From: 321Tim Subject: Superior XP-360 Oiling system changes (long)] Interesting comments on the Superior XP-360 from a Sun&Fun attendie. 321Tim From: Charles Kuss Date: Wed Apr 9, 2003 3:59 pm Subject: Superior XP-360 Oiling system changes (long) To: vansairforce@y..., bmarvel@c... While at Sun N' Fun, I attended Superior's forum on the XP360. From what I learned there, the engine sounds great. Sunday afternoon, I stopped by the Superior tent. I asked the alleged (the guy's lack of knowledge about his product bordered on criminal) salesman to show me how and where Superior had modified the oiling system to achieve "balanced" oil flow. The salesman attempted to explain the oiling system to me. It became apparent to me within 30 seconds that this individual had no clue what he was talking about. I waited around and spoke to Superior's engineer when he came back to the tent. While I waited, I tried to separate the display case halves in the tent. No go, they were bolted together. I wanted to determine exactly WHAT Superior had done to achieve their claim of "balanced" oiling. By groping with my fingers, I was able to determine that all Superior had done, was to move the oil source for the forward and middle camshaft journals from the right side oil galley to the left side. When the engineer returned, he confirmed this. I asked him if he was aware of the complaints that Bill Marvel and Bill Scott had published regarding Lycoming's oiling system. See http://eaga.home.mindspring.com/valves.html to get up to speed on this issue. The engineer told me that it was after reading these articles, that he decided to see if something could be done to improve the situation. I asked if Superior had done any testing to verify that they had achieved a "balanced" oiling system to the cylinder heads. He told me that they had NOT done any scientifically accurate tests. They had simply removed the valve covers on the XP 360, run the engine and collected the oil which drained out of the cylinder head area into coffee cans. He stated that visually the flow appeared to be fairly equal. They left it at that and did not do any further testing. I appreciate his honesty and candor. However, his answer did not fill me with confidence. It seems odd to me that a company would deviate from Lycoming's oiling system based on Mr. Marvel's and Mr. Scott's testing. YET, not do verification testing as detailed as Mr. Scott/Marvel did in the first place, to determine if the modifications had succeeded. Superior seems to have used the TLAR (that looks about right) method of verification testing. The gentleman I spoke to (I've forgotten his name) told me that Superior's testing of the 360 cu. in. Lycoming indicated that there was a fair amount of "pulsation" of the oil pressure on the right side oil galley. He stated that the modifications that Superior made, have improved this situation. Would anyone with a flying XP-360 be willing to make their engine available to Mr. Scott for verification testing? Would Misters Marvel and Scott be willing to test Superior's claims? For my own edification, this afternoon I examined the crankcases of my own O-360-A4K engine. This is a 2nd design 360 crankcase (1978). I was told by my local engine overhaul facility (AirMark at FXE) that Lycoming has since changed their crankcase design again. (3rd generation). My crankcase has oil feed holes to all 3 camshaft bearing surfaces originating from the right side, as mentioned by Misters Scott and Marvel. My crankcase ALSO has an oil feed hole supplying oil from the left crankcase half to the forward most journal surface. From this observation, there are only 2 differences between my Lycoming 2nd generation crankcase set and Superior's new crankcase design. My #1 (forward most) camshaft journal is oiled from both case halves. The Superior is oiled only from the left. My #2 camshaft journal is oiled from the right. The Superior cases supply oil only from the left. While I may be wrong, this minor change seems insufficient to me, to create a "balanced" oiling system. Tomorrow morning my friend Eric Hensen and I will continue our re-assembly of his 1967 IO-320 engine. I will examine his oiling system very carefully. I want to see if there are differences between my 1978 engine and his 1967 engine's oiling system. I would also greatly appreciate it if anyone could enlighten me as to any changes that Lycoming has made with it's 3rd generation crankcase design. I would greatly appreciate the comments of all who can further enlighten me on this subject. Charlie Kuss RV-8A cockpit systems stuff PS I had a great time volunteering at Sun N' Fun. +++ #17076 From: "ken wardstrom" Subject: #357 psru FRED, our reduction unit is our own design, but incorperates design idea's from other existing unit's.Some of the spec's are: -ratio 2:1 small pulley-30 tooth big pulley-60 tooth -pulley's are 6061 t6 hard anodized -belt is polychain gt2 14mm tooth x 37mm wide -lower shaft is held between two bearings and splined to fit corvette clutch spring center section -the prop shaft and flange is hollow and machined from a single 6.5" dia. piece of 4140 steel -we made the patterns for the propshaft bearing houseing and had that cast in almag -the houseing has an eccentric ring for tightening the belt So far we have 20 hrs. of running ( 10@ 70% and 5@100% ) while we have been doing static tests to check the cooling system and other components of our auto conversion. So far everything is okay but only time will tell - ken +++ #17214 From: "t18cox" Subject: MP14 weight There is a lot of discussion here from time to time about the MP14. Recently at the http://www.gf24.de/biplane/ website the engine weight thing came up and a detailed breakdown of Kevin Kimbal's fwf was included. 689 pounds. ... Bill Cox #303 +++ #17656 From: "ken wardstrom" Subject: #357 weight Russ, as near as we can make out our motor & prop package is within 10 lbs. of the 540 pkg. ( hard to tell tho, all the air cooled guys lie so much). Some of the things that have added weight are : - bottom skins .032 - full epoxy primer inside wing skins ( everywhere ) - 1.5' cap strips - full hot water heater and defroster system - dual high and low pressure fuel pumps - 13lb. alt. - dual msd-6a ign. boxes -dual ecu's - extra gauges for the auto pkg. ( and our own testing info. ) Pat, neither of us will be doing the test flight, that will be done by Mike Langford with dad as the flight engineer. Dad has just passed his medical to reinstate his licence and Mike is going to use the bearhawk to give dad some dual time and recertify him. The only licenc i have at this time is my hovercraft licence ( for vertically challenged pilots = 1/2" above the water ), but now that the plane is basically finished i will begin the full program - ken +++ #17824 From: charles.k.scott@d... Subject: New GA engine > At the risk of getting you (re)started--why do you say a "basic > automotive source engine"? Is that because of the economy of scale > of using something built in large numbers instead of low volume > purpose-designed "aircraft" engines? This is a really complicated subject. Current aircooled direct drive GA engines are a bundle of compromises. So are airframes and just about everything that has to do with an airplane. Let's just start with the prop. A direct drive prop limits the engine to a relatively low rpm because spinning it too fast makes a lot of noise and reduces efficiency. Reduction of max rpm reduces the power the engine can produce. The only way to make more power, given the rpm limitation is to make it bigger, or supercharge it. Supercharging is super expensive so making it bigger is how things have gone so far. All the high horsepower military engines used in WWII were NOT direct drive. This went for the inline engines as well as the big radials. Using a reduction unit allows the engine to run faster which means the cubic inch displacement can be reduced. Reducing the CID allows everything to be made lighter. The only thing that isn't better with smaller engines is the BSFC. For this, very large, extremely slow engines normally turn in the best figures. But PSRU's are complicated, expensive and add weight. This is getting to be a "YEAH"/"BOO" kind of monolog. There's not much wrong with the current automotive V-6's. They are designed and tested under a testing schedule that is so much more severe than what is specified for a certified aircraft engine that it amounts to hellish destruction. They are compact, efficient and lightweight. They are designed from the ground up for great oil and coolant circulation and most these days incorporate things like roller lifters and roller tappets. Or overhead cams. And they are produced in the millions each year. Think of that, millions of different V-6's produced each year. You can buy a high performance short block for $3K. That's an engine with everything in it but the intake manifold and the water pump and ignition system. And that's retail. The crank ALONE for a typical 0-360 will run you some $6,000 to $8,000. The figures are really tantalizing, but it's almost impossible to make money doing an auto conversion. Bud's right, the economics just aren't there and probably never will be unless some filthy rich aviation crazy philanthropist decides to create the everyman's aircraft engine and gives them away for $10,000. Then, he'd probably be sued into his grave when the first one goes down for whatever reason. Corky Scott +++ $Id: 2.7b-FirewallFwd,v 1.1 2003/05/22 03:41:33 bentonh Exp $