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#11
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SLOL/LSA Expectations
"aerojones" wrote in message ... Hi I'm conducting a survey for my aeronautics course and I was hoping you all could help me out. I'm focusing on smaller single reciprocating, nonturbine engine aircrafts and I wanted to know what are the most important features/expectations when considering a STOL and/or Light Sport aircraft? Whether you are looking to buy, build, or just fly. Any and all opinions are appreciated. Thanks -- aerojones price Safety usability (ie flyable in moderate wind) standard parts (lower cost of ownership) |
#12
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SLOL/LSA Expectations
Morgans wrote:
"Rocky" wrote I am going to use a Suzuki 1300cc (70 hp) with a belt reduction unit. I had a Samurai for 14 years with this exact engine in it. On the freeway its almost full throttle and turning 36- 3800 RPM hour after hour. Will be the same RPM in the plane at cruise. All up engine wt is about 50 lbs LESS than the VW. I am still welding the fuse so have few pics Sounds cool. I would love to see it, if and when you put some pictures somewhere we can see them. I have to admit having given that engine some consideration. Now, I have been thinking about the Chevy engine they are putting in the Cobalts. They have a model that is turbocharged that would make a really cool turbo normalized setup. Good thing, if you put it into a LSA, and put a steep enough prop to keep it under speed at low altitudes, and let it crank up at altitude. Zoom! g I wonder how the final cost and weight would compare to a Rotax 914??? |
#13
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SLOL/LSA Expectations
On Feb 4, 4:36*am, cavelamb wrote:
I wonder how the final cost and weight would compare to a Rotax 914??? Based on a quick internet search the Rotax is about 40 pounds less and between 2 and 3 times the price. http://www.ultralightnews.ca/rotaxengineprices/6.html http://www.raven-rotor.com/ http://www.rotaxservice.com/rotax_en...tax_914ULs.htm I can second the statement that the 1300 in a Samurai is operated at an aircraft power profile while on the interstate. Pedal to the floor and shift down on hills when the rpm drops below peak torque is normal operating procedure. In my case it was a necessity to keep the speed up. Dropping below 60 meant the onset of divergent shimmy about the lateral axis until the speed dropped below 40 or so. |
#14
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SLOL/LSA Expectations
As for the original thread -
Along with being reasonable to purchase and operate, implying a "take home" plane, it should not be so fragile that ground handling becomes a problem. Another factor that I think is going to become even more important ............. it should have a power plant that can operate on standard auto fuel - alcohol and all. If snowmobiles and 4 wheelers can operate at 14,000+ ft density altitudes on auto fuel there must be a way to make LSA's do the same? =========================== Leon McAtee |
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SLOL/LSA Expectations
On Feb 3, 6:32 pm, "Morgans" wrote:
wrote 3600 or 3800 RPM on the highway is a LOT different than 3600-3800 in the air. The highway vehicle is using about 25-35% of its power capacity. Its throttle is maybe half open at the most. Check yours again and see. In the airplane, 75% is more like it and the throttle is three-quarters of the way open. Not necessarly true in the case of the Sameri. It is a boxy little car, with tons of drag, and a little engine. He said it was near wide open, and that would not surprise me. That said, Raven Redrives have a couple of Suzuki conversions. It seems to have proven itself, fairly well, in airplanes. -- Jim in NC I should have addressed the RPM issue a little further. What's the redline RPM of that engine? Around 6000, I think. So at 36 or 3800 RPM, even at full throttle, we're not pushing it to anywhere near max power output, which we'd prefer from such a tiny engine in an airplane. We might be getting max torque from it, but HP consists of both torque and RPM, and at high RPM and full throttle there will be much more stress on the engine and more waste heat generated. Raven says they run theirs at around 4000 so they're giving up some power in the interest of longevity, but they end up with a poorer power-to-weight ratio. Dan |
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SLOL/LSA Expectations
wrote in message ... As for the original thread - Along with being reasonable to purchase and operate, implying a "take home" plane, it should not be so fragile that ground handling becomes a problem. Another factor that I think is going to become even more important ............. it should have a power plant that can operate on standard auto fuel - alcohol and all. If snowmobiles and 4 wheelers can operate at 14,000+ ft density altitudes on auto fuel there must be a way to make LSA's do the same? =========================== Leon McAtee The more frustrating problem might be to make it run on av-gas, although echanics have also told me that may be a non-issue as well. Basically, if you are willing to accept the as delivered reliability of the automotive FADEC systems, which have become very good, then the primary issue would be lead fouling of the oxigen sensor--the the mechanics have told me that the oxigen sensors do not fail in the conventional sense, due to lead fouling; but only become slow in their operation. Since aircraft engines are normally operated at continuous output levels, and the FADEC systems are capable of operating with enriched mixture in open-loop mode when at maximum power and also while the oxigen sensor catches up, the lead fouling problem may be trivial in most cases. Just a thought, for what it's worth and withh the understanding that I am not really taking a position. In fact, there appears to be mounting evidence that the total cost of a conversion might not be much of a saving over the purpose built aircraft engines. Peter |
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SLOL/LSA Expectations
"cavelamb" wrote I wonder how the final cost and weight would compare to a Rotax 914??? It could be as much as a boat anchor more than a Rotax 914, and twice the cost, and I would still prefer it. -- Jim in NC |
#18
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SLOL/LSA Expectations
Peter Dohm wrote:
... if you are willing to accept the as-delivered reliability of the automotive FADEC systems, which have become very good, then the primary issue would be lead fouling of the oxygen sensor... Peter Yes. It is not contentious to mention that the longevity of auto engines has increased by leaps and bounds since the advent of FADECs. Longevity does not equate to reliability exactly, but electronic ignition has been helpful, I believe crucial in fact, and mechanical design of self adjusting lifters is no longer a black-art. It seems to me that the water-cooled engine can be made to cope with the high rejected-heat associated with high throttle operation. There is still a question in my mind about the heat-shedding arrangements for lube oil but an oil radiator is nothing new, and exhaust valves would benefit from some premium qualities. Brian W |
#19
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SLOL/LSA Expectations
Morgans wrote:
"cavelamb" wrote I wonder how the final cost and weight would compare to a Rotax 914??? It could be as much as a boat anchor more than a Rotax 914, and twice the cost, and I would still prefer it. Care to share the "why", Morgans? I've flown the 912 and liked it a lot. Haven't had the opportunity to fly a 914 tho. |
#20
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SLOL/LSA Expectations
On Feb 4, 6:16*pm, Brian Whatcott wrote:
Peter Dohm wrote: ... if you are willing to accept the as-delivered reliability of the automotive FADEC systems, which have become very good, then the primary issue would be lead fouling of the oxygen sensor... Peter * Yes. It is not contentious to mention that the longevity of auto engines has increased by leaps and bounds since the advent of FADECs. Longevity does not equate to reliability exactly, but electronic ignition has been helpful, I believe crucial in fact, and mechanical design of self adjusting lifters is no longer a black-art. *It seems to me that the water-cooled engine can be made to cope with the high rejected-heat associated with high throttle operation. There is still a question in my mind about the heat-shedding arrangements for lube oil but an oil radiator is nothing new, and exhaust valves would benefit from some premium qualities. Brian W You are right in your thoughts,,, I fly one almost every day to prove your point.... Ben www.haaspowerair.com http://video.google.com/videoplay?do...50730841&hl=en |
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