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Aviation Forum / General / Homebuilt / February 2005Cozy, Long ezy, and diesel engine.
Please excuse my ignorance, but I've been reading a lot of hoopla over 2 stroke diesel aircraft engines. Has anybody tried one of these in a Cozy or Long Ezy? It sounds to me like that may make for a very fuel efficient aircraft with good performance. Any reason why it can't be done? If the aircraft is home built, could it burn standard diesel even though it hasn't been approved by the FAA? Is there a good reason not to use standard diesel other than fuel congealing at cold temperatures?  Signature"Don't be misled, bad company corrupts good character." www.LCTPaintball.com www.LCTProducts.com > Please excuse my ignorance, but I've been reading a lot of hoopla over 2 > stroke diesel aircraft engines. Has anybody tried one of these in a Cozy or > Long Ezy? I am no expert, but I'll give it a shot. Problem number one, they are all in test phase, or prototype, and not available, AFAIK. >It sounds to me like that may make for a very fuel efficient > aircraft with good performance. Any reason why it can't be done? Nope, and when they are out there at reasonable costs, lots of people will be wanting to get ahold of them. Problem now is, they have been going to be available to the public in the next six months, for the last five years. Get my drift? Some people are home-brewing 4 stroke diesels, from cars, and had pretty good luck. I recall one being in a pusher. > If the aircraft is home built, could it burn standard diesel even though it > hasn't been approved by the FAA? For experimental, you could burn peanut oil, as far as the FAA cares. >Is there a good reason not to use standard > diesel other than fuel congealing at cold temperatures? Sounds like a damn good reason to me! :-) One of the big reasons that people want diesels, is that they could burn the jet fuel that is at all major airports, and lots of minor ones. <g> SignatureJim in NC "> >>It sounds to me like that may make for a very fuel efficient >> aircraft with good performance. Any reason why it can't be done? [quoted text clipped - 4 lines] > available to the public in the next six months, for the last five years. > Get my drift? You're saying that they just aren't available, not that they wouldn't be efficient when they're available, right? > Some people are home-brewing 4 stroke diesels, from cars, and had pretty > good luck. I recall one being in a pusher. I thought those had some weight issues. > Sounds like a damn good reason to me! :-) True, but that issue can be fixed. > One of the big reasons that people want diesels, is that they could burn > the > jet fuel that is at all major airports, and lots of minor ones. <g> Yea, but standard diesel is much cheaper. > "> > >>It sounds to me like that may make for a very fuel efficient [quoted text clipped - 8 lines] > You're saying that they just aren't available, not that they wouldn't be > efficient when they're available, right? Right > > Some people are home-brewing 4 stroke diesels, from cars, and had pretty > > good luck. I recall one being in a pusher. > > I thought those had some weight issues. Some have done a pretty good job of keepng the weight down, and it really matters what you start from. > > Sounds like a damn good reason to me! :-) > > True, but that issue can be fixed. That comment was about fuel jelling. What are your fixes? Will it end up making the cost higher? What happens when you go to other airports that don't have auto diesel fuel? > > One of the big reasons that people want diesels, is that they could burn > > the > > jet fuel that is at all major airports, and lots of minor ones. <g> > > Yea, but standard diesel is much cheaper. SignatureJim in NC >> True, but that issue can be fixed. > > That comment was about fuel jelling. What are your fixes? Will it end up > making the cost higher? What happens when you go to other airports that > don't have auto diesel fuel? The first fix would be to pump extra fuel through the system so that it can be warmed by the engine, then returned to the tank. Perhaps you could even run it through the oil cooler before sending it to the engine. There are also additives that are routinely used to keep the fuel from jelling. My understanding is that these engines are actually multifueled. You could run them from diesel fuel, Jet-a, or any combination of the 2. If I understand the issues correctly, the turbo charged diesel engines retain most of their power even at high altitudes (around 25K). And, they give about 30% improvement in fuel efficiency over av gas. Please understand you're speaking to a complete novice here. I was hoping to glean knowledge from you guys. > >> True, but that issue can be fixed. > > [quoted text clipped - 6 lines] > run it through the oil cooler before sending it to the engine. There are > also additives that are routinely used to keep the fuel from jelling. The additives will be the best bet, but expensive, when you add that to the price for fuel. Truckers use it, but they are only dealing with negative in the teens, not 20 to 30 below, with a huge moving air factor, around the fuel. All that fuel, basicly in direct contact with the air, with Al's great thermal conductivity. You would need to insulate the tank. Not easy, and more weight. Now add in whatever fuel heat exchangers, lines, and pumps, and more weight, and also, complexity. (read ways to bring you down before you wanted to) I didn't do any calcs, but you would need to capture almost all of the engine's waste heat to do this without additives. I realize that you would not be in that kind of temperatures all of the time, but all you need is one time where things were colder than you thought, and...... Many around here will talk about the hassles of using your own auto fuel, and what happens when you travel away from home. That is what the airplane you are describing will be good at; great economy, and legs. Shoot, one nutcase that hangs out around here even made his own fuel truck to feed his habit. <g> The old saying about asking how much fuel that yacht burns? If you have to ask how much fuel it burns, you can't afford the boat. Same thing here. Jet fuel is not that bad, it will give you great economy, and it is available, and won't end up killing you. Just my humble opinions. SignatureJim in NC > > >> True, but that issue can be fixed. > > > [quoted text clipped - 35 lines] > Same thing here. Jet fuel is not that bad, it will give you great economy, > and it is available, and won't end up killing you. Just my humble opinions. You could use the fuel as an engine coolant in a liquid cooled diesel like the Deltahawk. With a wet wing, you'd get hot wing anti-ice capability and a skin radiator in the bargain. 'Course, it wouldn't work if you ran out of fuel.....:) Bill Daniels >You could use the fuel as an engine coolant in a liquid cooled diesel like >the Deltahawk. > >With a wet wing, you'd get hot wing anti-ice capability and a skin radiator >in the bargain. 1960's vintage Allis Chalmers crawlers using the diesel fuel as a cooling medium and working medium for the torque converter. Worked well. tom > >You could use the fuel as an engine coolant in a liquid cooled diesel like > >the Deltahawk. [quoted text clipped - 5 lines] > medium and working medium for the torque converter. Worked well. > tom would a mazda/wankle-rotary run on Jet-A, JP-4, etc? No. The Mazda rotary engine is an Otto cycle engine, the same cycle used in a piston engine. Jet fuel has too low an octane rating for an Otto cycle engine, you would get pre-ignition. You would have to convert it to direct fuel injection to use these low octane fuels. You wouldn't gain much efficiency unless you also found a way to significantly increase the compression ratio as well. > would a mazda/wankle-rotary run on Jet-A, JP-4, etc? SignatureBryan Martin Compression ignition Wankel-type rotaries have been built and run. Bill Daniels > No. The Mazda rotary engine is an Otto cycle engine, the same cycle used in > a piston engine. Jet fuel has too low an octane rating for an Otto cycle [quoted text clipped - 4 lines] > > > would a mazda/wankle-rotary run on Jet-A, JP-4, etc? True, but not by Mazda. > Compression ignition Wankel-type rotaries have been built and run. > [quoted text clipped - 9 lines] >> >>> would a mazda/wankle-rotary run on Jet-A, JP-4, etc? "Dan Nafe" <dan@scuba-training.net> wrote > > > > > >You could use the fuel as an engine coolant in a liquid cooled diesel like > > >the Deltahawk. [quoted text clipped - 7 lines] > > would a mazda/wankle-rotary run on Jet-A, JP-4, etc? If it did, it would come the closest chance of having waste heat deice the wing. Wankel engines do not have a high enough compression ratio, I believe. The other issues have been kicked around before. 1.) Wings make poor radiators. The boundary layer of air does not move enough, to carry the heat away efficiently. It was tried, even in the early years of air racing. 2.) Internal combustion engines do not produce enough waste heat to deice a wing, even if 100% of the exhaust heat and engine cooling heat was captured, and put onto the wing. 100% will never happen, and that makes the possibilities even more unlikely. SignatureJim in NC > "Dan Nafe" <dan@scuba-training.net> wrote > > > > > > [quoted text clipped - 27 lines] > and put onto the wing. 100% will never happen, and that makes the > possibilities even more unlikely. Seems counter to say that a skin radiator won't cool an engine but won't de-ice either. Last I checked, ice melted at 32F and coolant is usually 180-200F. If the skin radiator won't transfer heat to the airstream, it'll get damn hot. If the heat won't melt ice, it's going somewhere. I'd bet a 180F wing would melt ice pretty damn well with an OAT of 28F. Actually, the golden air age racers with skin radiators worked pretty well. BTW, if heat won't transfer through a wing boundary layer, why should it transfer through the boundary layer on a cooling fin? Bill Daniels > Seems counter to say that a skin radiator won't cool an engine but won't > de-ice either. Last I checked, ice melted at 32F and coolant is usually > 180-200F. If the skin radiator won't transfer heat to the airstream, it'll > get damn hot. If the heat won't melt ice, it's going somewhere. It takes a lot of energy to melt ice. What is it, specific heat? I can never remember if it is that, or latent heat, from my high school chemestry. Ever notice how small the radiators are, in a auto engine homebuilt? Lots of the 4.3 Liter V-6's are using 2 Chevy air conditioner evaporators. How much surface area, if it were all spread out? 3 or 4 square feet would be my guess. Now take the wing of of a RV. What are they, 100, 120 sf? That makes it 200 or 240 square feet, top and bottom. Oh, let's take off 20% for ailerons and flaps... 190 or so. 47 times more surface on the wing, than the radiator. How hot do you think that will get, with all of that air zooming by at 150 + MPH. Yes, if you made the whole wing a radiator, the coolant will get cooled. How much will all of it weigh? Some time ago, someone in the group did some calculations, that pretty much proved the case. They used the efficiency of an IC engine, then assumed that all the rest of the BTU's produced by burning, say 10 gal/hr, that were not used for HP went into the wing. They started with a thin layer of ice over a given surface area, and calculated how much heat it wuld take to melt that ice. The waste BTU's in that gas were far short of melting all of it. > I'd bet a 180F wing would melt ice pretty damn well with an OAT of 28F. If you put the heat in a small surface area, say the first 6" of the leading edge, yes. What happens after it runs back and re-freezes? Seems to me, a commuter plane model had a problem with that type of thing, and a couple crashed, a few years back. If the wing was 180 without the ice, how well would the engine be cooling. (or overheating) > Actually, the golden air age racers with skin radiators worked pretty well. Cites? > BTW, if heat won't transfer through a wing boundary layer, why should it > transfer through the boundary layer on a cooling fin? > > Bill Daniels I am not an aerodynamoisist, but I think there is something you are not understanding, here. I do not believe boundry layers apply, when the air is being forced past the surface, with nowhere else to go, with a pressure differential. Ever notice the lip on the cooling intake of a P-51? It is away from the surface of the belly by a few inches, away from the boundry layer, to get to where the air is flowing fast, and energetic, and pressure can be developed, due to ram effect. The other big part of the equation is the negative pressure behind the lip of the outlet. How does your cite of boundry layer apply to a radiator? For my final argument, why are wing radiators not commonplace? If you could get the engine cooled, for no drag penalty, why is it not being done? Surely Dick Rutan would have used it in Voyager, to eliminate the cooling drag. What is cooling drag in a piston airplane? I seem to recall around 20% on most designs. 20% on Voyager would have been HUGE! SignatureJim in NC >>Seems counter to say that a skin radiator won't cool an engine but won't >>de-ice either. Last I checked, ice melted at 32F and coolant is usually [quoted text clipped - 16 lines] > zooming by at 150 + MPH. Yes, if you made the whole wing a radiator, the > coolant will get cooled. How much will all of it weigh? I don't know the area of a typical car radiator either, but I'm betting it is much more than 3-4 square feet. Also, keep in mind that you only need to de-ice the leading edge of the wing (look at how much boots cover). So the area is probably closer to 2' times the wingspan which means 50-80 sq. ft. one a typical light airplane. And you don't need to coolant at 180F+ to deice a wing, so you can push the coolant through a lot more area than a radiator and still keep sufficient temperature to melt or prevent ice. > Some time ago, someone in the group did some calculations, that pretty much > proved the case. They used the efficiency of an IC engine, then assumed > that all the rest of the BTU's produced by burning, say 10 gal/hr, that were > not used for HP went into the wing. They started with a thin layer of ice > over a given surface area, and calculated how much heat it wuld take to melt > that ice. The waste BTU's in that gas were far short of melting all of it. Preventing it is easier than melting an accumulation to be sure. This holds with other systems such as TKS as well. > For my final argument, why are wing radiators not commonplace? If you could > get the engine cooled, for no drag penalty, why is it not being done? > Surely Dick Rutan would have used it in Voyager, to eliminate the cooling > drag. What is cooling drag in a piston airplane? I seem to recall around > 20% on most designs. 20% on Voyager would have been HUGE! I'd guess cost and complexity would be two big reasons. Matt >>>Seems counter to say that a skin radiator won't cool an engine but won't >>>de-ice either. Last I checked, ice melted at 32F and coolant is usually [quoted text clipped - 58 lines] > > Matt Could you add cooling fins to a wing? Would a serious set of vortex generators add enough area? > I don't know the area of a typical car radiator either, but I'm betting > it is much more than 3-4 square feet. Yes, car radiators are much larger than 3 or 4 square feet. Car radiators have to sit in traffic, not moving, in 110 degrees. Also, they have even hotter air blowing past them, from the AC radiator in front of it. Automatic transmission cars also have to cool the tranny fluid, by running it through the radiator. That represents a huge amount of heat. Most water cooled homebuilts do not tolerate sitting on the taxiway more than a few minutes. How do I know that? By talking to the owners of them, when they are deciding about when to taxi, and how long they can stand it. There are exceptions; some have figured out how to cool their engines, sitting on the ground for a long time. They are the exception, in the homebuilt world. So really, that is how they get away with such small radiators. Lots of cool fast moving air. > Also, keep in mind that you only > need to de-ice the leading edge of the wing (look at how much boots > cover). Different princples at work. If you *melted* the first few inches of ice, it would run back and re-freeze, before it got off the wing. Bad thing. VERY bad thing, as in guaranteed crash, after about 1/4" of ice. > So the area is probably closer to 2' times the wingspan which > means 50-80 sq. ft. one a typical light airplane. Nope, see above. Good for crashing, if it did stay hot enough to melt ice. > And you don't need to coolant at 180F+ to deice a wing, so you can push > the coolant through a lot more area than a radiator and still keep > sufficient temperature to melt or prevent ice. You will have to add another pump (more weight) to move that "cooler" water, then. ALL of the water that comes out of the engine is at 180 degrees. > Preventing it is easier than melting an accumulation to be sure. This > holds with other systems such as TKS as well. Different, once again. Preventing it from forming on the leading edges, and letting it freeze further back does no good. TKS keeps everything that runs back from freezing, because the antifreez has mixed with all of the water running back, to make a mixture that is above freezing. If you melt it at the front of the wing with heat, the water must stay hot enough to run ALL OF THE WAY back, and off of the wing. Jet engines have enough waste heat to do that. IC engines DO NOT. Get that through your head! It is not done, because it CAN NOT be done! Get it? > > For my final argument, why are wing radiators not commonplace? > I'd guess cost and complexity would be two big reasons. Yes, but you missed the biggest one. Weight. Weight. Weight. If it were cost and complexity, someone would still do it. They *will not* sacrifice the weight. SignatureJim in NC >> Also, keep in mind that you only >>need to de-ice the leading edge of the wing (look at how much boots [quoted text clipped - 3 lines] > it would run back and re-freeze, before it got off the wing. Bad thing. > VERY bad thing, as in guaranteed crash, after about 1/4" of ice. I couldn't find any definitive references with a quick search, but I'm pretty sure that jets with heated wings, only heat the leading edge, not the entire wing surface. I suspect that the ice melts slowly enough that it evaporates (or sublimates) long before it can run back over the wing. >>So the area is probably closer to 2' times the wingspan which >>means 50-80 sq. ft. one a typical light airplane. [quoted text clipped - 20 lines] > enough waste heat to do that. IC engines DO NOT. Get that through your > head! It is not done, because it CAN NOT be done! Get it? Sorry, I've not seen any data that supports this conclusion. I don't think Jet engines are that much less efficient than piston engines, especially given that amount of heat they directly eject out the tailpipe. >>>For my final argument, why are wing radiators not commonplace? > [quoted text clipped - 3 lines] > cost and complexity, someone would still do it. They *will not* sacrifice > the weight. Yes, I'm sure weight is another reason, although this could be minimized if the coolant channels were formed integrally with the leading edge skins. However, that would then bring back the cost issue. Matt > Sorry, I've not seen any data that supports this conclusion. I don't > think Jet engines are that much less efficient than piston engines, > especially given that amount of heat they directly eject out the tailpipe. Pure volumes of fuel burned, is the all important factor. What does a modern airliner burn per hour. Doug, or other jet qualified dude? 50 galons per hour for a regional turbo prop? 100 or more for a smaller turbofan? Compared to 20 or 25 for a piston. Not even in the ballpark. Not enough energy avaliable. That many gallons being burned is a lot of energy available, and a percentage can be used for anti ice. It is no free lunch, and the jets burn more fuel when the anti ice is on. I don't know how much, but it is a large enough factor to have to be calculated, AFAIK. Bleed air is used, and that is capable of a tremendous volume, at a high temperature. An airplane piston engine might be able to make that much heat and volume from comperssed air, if it ran a rotary comperssor, and didn't have to mess with a propellor. It would not fly very good without a prop! <g> You also mentioned the water running back, only being heated from the front with jets. OK, but they can heat it hot enough to evaporate some of it, and get the rest hot enough that it does not refreeze before running off. The piston engines could not put enough heat out, like the turofans. Even the turboprops have to use boots. > Yes, I'm sure weight is another reason, although this could be minimized > if the coolant channels were formed integrally with the leading edge > skins. However, that would then bring back the cost issue. > > Matt If it would work, someone would have done it, with the cost not being an object. The weight issue is too much to overcome, along with the complexity. Still, the whole thing comes back around to the fact that it demands more energy than is available. Give it up. I know you won't; you just want to tilt at windmills. That's OK, if that is your thing. It is not mine. I'm done here. Good luck. SignatureJim in NC > If it would work, someone would have done it, with the cost not being an > object. The weight issue is too much to overcome, along with the [quoted text clipped - 3 lines] > Give it up. I know you won't; you just want to tilt at windmills. That's > OK, if that is your thing. It is not mine. This is nonsense of the highest degree. Everything that has ever been done has been done a first time. In the piston world, no one is going to throw a lot of money at this unless they think they can do it cheaply. Otherwise, they are wasting their money. So to say that someone would have done it regradless of cost seems wrong to me. The market potential is pretty small, so unless something is obvious, it won't get done for profit. It will get done by someone who wants to know how, why, or what if. If you know how a jet can do it, then all you have to do is find out how much you have to lighten the system, and how much energy you need to add to the system. You are helping by pointing out the problems that need solving, but not by saying they are unsolvable. This has been very interesting to me, a novice. But, my original intent was to create enough heat to keep the fuel from jelling, not to de-ice the wings. With that goal in mind, the wings could actually be insulated to help hold the heat. There would be very little added cost, or weight. A fuel pump (which is already on the aircraft) could simply pump more fuel that is needed to the engine. Some of the fuel would be burnt, while some of the fuel would run through a heat exchanger from the radiator, or engine oil, then simply return to the tanks. > This has been very interesting to me, a novice. But, my original intent was > to create enough heat to keep the fuel from jelling, not to de-ice the [quoted text clipped - 4 lines] > fuel would run through a heat exchanger from the radiator, or engine oil, > then simply return to the tanks. Sorry you got lost in the rush of absurdity. Your problems are solveable. Yes, the fact that the tanks you are using will be fiberglass over foam, instead of aluminum, would give you a pretty good chance of your idea working. Keep in mind that you will not always be able to get auto diesel. Be sure that your engine will be able to burn jet A. There was some talk about auto engines, and jet A. Seems the injection pumps on most auto engines can not stand up to jet A. The auto diesel has good lubrication qualities, while jet A has no lubricating qualities. The seals wear completely out, and the pump stops injecting. The diesel engines now flying, like the Thielert, (or however it is spelled) have seals that do not depend on lubrication from the fuel, so no problem. I recall that it can burn auto fuel, also, but I'm not sure on that one. Perhaps someone out there knows that answer. If I were going to do what you are thinking about, I would put a thermometer in the tank(s), and also include a heat exchanger bypass, so when you are burning jet fuel, you can stop heating the fuel. SignatureJim in NC . I recall that it > can burn auto fuel, also, but I'm not sure on that one. Perhaps someone > out > there knows that answer. The Thielert can run auto diesel in europe, but the american mixtures are not recommended due to high sulfur and other contaminants. This will likely change in 2006. > Sorry you got lost in the rush of absurdity. Your problems are solveable. I'm not sorry. I haven't been around long enough to even ask good questions, so this kind of discussion really gets me thinking. I love to invent new things. I have the skills and tools to do so, but I don't have the expertise in the aircraft industry, yet. > Yes, I'm sure weight is another reason, although this could be minimized > if the coolant channels were formed integrally with the leading edge > skins. However, that would then bring back the cost issue. > > Matt Heh, Matt. Why build the complexity of a channel. Use a coolant that doesn't evaporate and just spray the coolant on the inside of the wing. Collect it in a sump at the wing root. Considerable dihedral would be beneficial. >Heh, Matt. Why build the complexity of a channel. Use a coolant that >doesn't evaporate and just spray the coolant on the inside of the wing. > Collect it in a sump at the wing root. Considerable dihedral would be >beneficial. Seems like there'd be considerable danger of sucking air into the sytem during an ucoordinated turn though, unless you had a LOT of extra coolant in the system. Mark Hickey :>Heh, Matt. Why build the complexity of a channel. Use a coolant that :>doesn't evaporate and just spray the coolant on the inside of the wing. [quoted text clipped - 4 lines] :sytem during an ucoordinated turn though, unless you had a LOT of :extra coolant in the system. The coolant you spray and collect in the wings couldn't be pressurized, and the coolant in your engine pretty much has to be (OK, it doesn't HAVE to be, but it's much more effective if it is) So you'd want to collect the wing coolant with a low power, high volume pump, and run it through a fluid to fluid heat exchanger to cool the real engine coolant. More complex, and likely heavier, but you were really able to eliminate cooling drag it might be worth it. > I don't know the area of a typical car radiator either, but I'm betting > it is much more than 3-4 square feet. Also, keep in mind that you only > need to de-ice the leading edge of the wing (look at how much boots > cover). So the area is probably closer to 2' times the wingspan which > means 50-80 sq. ft. one a typical light airplane. I do. The radiators that several guys have been using to cool their 13B rotaries have about 14,000sq.in. of radiator surface area. That nearly 100sq.ft. There are alot of very thin fold of aluminum sheet that are exposed front and back. You'll need both sides of your wings and the fuselage belly. Add to that, the radiator is design to turbulate the air in order to mix it up. A wing is designed to keep the air smooth, and won't fly if you mix it up enough to to make it a decent radiator. If you melt the ice on the leading edge, it will refreeze just behind the leading edge, unless you can keep the laminar layer warm enough. There could possibly be some benefit to heating the bottom of the wing. The laminar layer is much thinner, and the heated air would add some lift energy. But the weight penalty of containing the coolant would be prohibitive. Maybe you could have an open system. A hose would spray coolant or engine heated oil on the inside of the wing skin and then flow back to a collector. Wouldn't deal with all the engine heat, but it could take a fair amount of it away. > The radiators that several guys have been using to cool their 13B > rotaries have about 14,000sq.in. of radiator surface area. That nearly > 100sq.ft. What kind of radiator is it? A custom racing job? I would be interested. How does it do on extended ground idle? You know what I was talking about, with the GM AC condensers, right? I believe that is what Tracy is running with his Mazda pusher. How much area would you suppose is in one of those? SignatureJim in NC >>The radiators that several guys have been using to cool their 13B >>rotaries have about 14,000sq.in. of radiator surface area. That nearly [quoted text clipped - 6 lines] > believe that is what Tracy is running with his Mazda pusher. How much area > would you suppose is in one of those? Those are the ones I'm talking about. I got the numbers from measuring a sample area in the radiator I have and calculating what that would be over the entire radiator surface. If you're really interested, the FlyRotary mailing list archives will reveal that quite a few planes are flying with this setup now. Unfortunately, I'm not one of them yet. Most had overheating problems initially, and had to make a modification or two to get things under control, but there are now quite a few examples of how to get 170Hp out of a rotary without overheating using a couple GM condenser cores. It the last few to report first flights have not had heating problems. > If you're really interested, the FlyRotary mailing list archives will > reveal that quite a few planes are flying with this setup now. [quoted text clipped - 3 lines] > of a rotary without overheating using a couple GM condenser cores. It > the last few to report first flights have not had heating problems. Wow, I never would have guessed that they have that much area. I'm actually a little bit skeptical. <g> I'm curious. Other than availability, why has that GM condenser become so popular? Any clues? SignatureJim in NC >> If you're really interested, the FlyRotary mailing list archives will >> reveal that quite a few planes are flying with this setup now. [quoted text clipped - 6 lines] >Wow, I never would have guessed that they have that much area. I'm actually >a little bit skeptical. <g> Look *closely* at a radiator. Notice how many of the 'vanes' there are in a linear inch. Now, consider how _deep_ the section is. Making up numbers out of thin air, if there are 6 vanes/inch, and depth of the assembly is 3 inches, you've got 18 inches of radiating surface for each square inch of 'frontal' area. For a 2'x3' frontal area, this comes out to 108 sq ft of radiating surface. 2'x 3' = 6 sq. ft frontal, * 18x for 'radiating' surface area >>If you're really interested, the FlyRotary mailing list archives will >>reveal that quite a few planes are flying with this setup now. [quoted text clipped - 9 lines] > I'm curious. Other than availability, why has that GM condenser become so > popular? Any clues? Tracy Crook used a couple from a junkyard, 'cause he got them for $5 each. He was going to just use them for sizing purposes, but they had the unfortunate quality of working very well, so he just kept them. Most builders have just sort of followed a proven design. It's cheap. It fits. It's lightweight. It works. I don't know if there is a better deal in aviation. > Tracy Crook used a couple from a junkyard, 'cause he got them for $5 > each. He was going to just use them for sizing purposes, but they had [quoted text clipped - 3 lines] > It fits. It's lightweight. It works. I don't know if there is a better > deal in aviation. Yea, makes sense. Don't break it if it ain't fixed! <g> I got to talk to Tracy a couple years ago, at OSH, and checked out his setup. Can't beat success. I was also impressed with some of his solutions of sealing and strengthening the hose attach fittings on the GM AC condensers. <g> SignatureJim in NC :would a mazda/wankle-rotary run on Jet-A, JP-4, etc? Google "Wankle Deere SCORE" > :would a mazda/wankle-rotary run on Jet-A, JP-4, etc? > > Google "Wankle Deere SCORE" Ah, that ugly little factor of weight and diesel engines, rears it's ugly head again. ;-) SignatureJim in NC > With a wet wing, you'd get hot wing anti-ice capability and a skin radiator > in the bargain. > > 'Course, it wouldn't work if you ran out of fuel.....:) > > Bill Daniels Couple years back, someone did a pretty good set of calculations on that. If you captured 100% of the engine waste heat, It wouldn't be even close enough to de-ice a wing. Turbines do it, cause they burn tons of fuel. IC engines don't come close. SignatureJim in NC > fuel. All that fuel, basicly in direct contact with the air, with Al's > great thermal conductivity. You would need to insulate the tank. Not > easy, > and more weight. Now add in whatever fuel heat exchangers, lines, and Cozies and Long ez's aren't aluminum. I haven't studied what the wings look like on the inside, but don't they already have foam in them? Do you still think they would loose too much heat? > pumps, and more weight, and also, complexity. (read ways to bring you down > before you wanted to) The fuel pumps are already there, and so are the fuel lines. The only thing you would be adding is a device to transfer the heat from the engine oil, or radiator to the fuel. I would think (read I'm not smart enough to do the calculations) that the improved airodynamics of not having to have a radiator in the wind would offset the extra weight of the heat exchanger. > Many around here will talk about the hassles of using your own auto fuel, > and what happens when you travel away from home. That is what the > airplane > you are describing will be good at; great economy, and legs. My understanding is that they run equally well off Jet-a. If there's not any diesel around, just filler up with Jet-a. > The old saying about asking how much fuel that yacht burns? If you have > to > ask how much fuel it burns, you can't afford the boat. That is a good statement for me. Money is always an issue. I have been known to spend $1,000 so I can save $100. ;) > Same thing here. Jet fuel is not that bad, it will give you great > economy, > and it is available, and won't end up killing you. Just my humble > opinions. I like that not killing me part. It's a rule that I try to live by. I also like opinions. They make me think..... > Cozies and Long ez's aren't aluminum. I haven't studied what the wings look > like on the inside, but don't they already have foam in them? Do you still > think they would loose too much heat? Right, I forgot that this was all about a long. Less loss, but it still is zipping through the air, to help. How much? I don't know. > The fuel pumps are already there, and so are the fuel lines. The only thing > you would be adding is a device to transfer the heat from the engine oil, or > radiator to the fuel. I would think (read I'm not smart enough to do the > calculations) that the improved airodynamics of not having to have a > radiator in the wind would offset the extra weight of the heat exchanger. If it did hold the heat real well, you might overheat the fuel, and have no way to cool the oil. Very bad. If this is a new tec engine, there is already a real big unknown added to your plane. The old experience around here says not to add too many new things to the mix, all at once. It adds to the chance of something going wrong. It will go wrong, you just have to hope not too bad. Nice thoughts, but I think it is valid to try to keep it simple. SignatureJim in NC > Please excuse my ignorance, but I've been reading a lot of hoopla over 2 > stroke diesel aircraft engines. Has anybody tried one of these in a Cozy > or Long Ezy? It sounds to me like that may make for a very fuel efficient > aircraft with good performance. Any reason why it can't be done? No, so long as the power is there to take off before the end of the runway. > If the aircraft is home built, could it burn standard diesel even though > it hasn't been approved by the FAA? Is there a good reason not to use > standard diesel other than fuel congealing at cold temperatures? US diesel is full of crud (someone else can tell you exactly what). If you could filter it, it may be okay, but for me, I would just as soon go with Jet A for the price. > "Don't be misled, bad company corrupts good character." > www.LCTPaintball.com > www.LCTProducts.com >Please excuse my ignorance, but I've been reading a lot of hoopla over 2 >stroke diesel aircraft engines. Has anybody tried one of these in a Cozy or [quoted text clipped - 4 lines] >hasn't been approved by the FAA? Is there a good reason not to use standard >diesel other than fuel congealing at cold temperatures? Go to http://www.deltahawkengines.com/ for the latest information and updates. Corky Scott Thanks, that is a cool sight! Apparently they will have the engines for sale next month. Signature"Don't be misled, bad company corrupts good character." www.LCTPaintball.com www.LCTProducts.com >>Please excuse my ignorance, but I've been reading a lot of hoopla over 2 >>stroke diesel aircraft engines. Has anybody tried one of these in a Cozy [quoted text clipped - 12 lines] > > Corky Scott "LCT Paintball" <nospampleasemnotlyon@mchsi.com> wrote in message > Thanks, that is a cool sight! Apparently they will have the engines for sale > next month. Good sig line. Tell you what. Get out your planner, then write down in one month, to check and see if the engines are shipping, right then. If not, write it down to check in a month. Repeat as necessary. There is some Latin saying about my attitude, but I don't remember it. SignatureJim (I'm really from Okalahoma; show me) in NC > Tell you what. Get out your planner, then write down in one month, to > check > and see if the engines are shipping, right then. If not, write it down to > check in a month. Repeat as necessary. I think I get your point. ;) > > Tell you what. Get out your planner, then write down in one month, to > > check > > and see if the engines are shipping, right then. If not, write it down to > > check in a month. Repeat as necessar > > I think I get your point. ;) Also known as the "Zoche syndrome." www.Zoche.com Ah, yes, I remember it well..........being excited by Michael Zoche's "pitch" back in....... I think it was 1980 !!! Neal > Tell you what. Get out your planner, then write down in one month, to > check > and see if the engines are shipping, right then. If not, write it down to > check in a month. Repeat as necessary. No doubt, the Liberty airplane has been ready to ship in 2 to 3 months for 2 to 3 years! Believe it or not, the jack a.s that sold all those useless orders is still selling airplanes. |
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