Hi everyone,
I'm quite new to this forum, I posted once before inquiring about plans built 4 place aircraft. However I'm on a fairly tight budget, and after thinking about it for a while I think that the cost of an engine for a 4 place airplane, and the operating costs for a 4 place airplane will be too high for my limited budget. So now I am considering 2 place aircraft.
Let me tell you a bit about myself. I'm not a pilot yet. I was taking flying lessons a couple of years ago, but then I had a snowmobile accident and had to put my lessons on hold and I haven't resumed them. I've got about 25 hours in a C172 and a Citabria though. I've always been interested in planes and aviation and it's always been my dream to have my pilot's license and my own plane. I'm a born experimenter, I love fabricating things and doing things differently than most people, which makes homebuilding a natural fit for me. To give you an example, I basically built my own snowmobile (I used mostly off the shelf parts though), installing every rivet and bolt myself, and then added an automotive turbocharger to the two stroke engine. This involved redesigning the fuel system, exhaust, intake system, ignition, and installing a pressurized oil system to lubricate the turbo. If you're interested in seeing pictures of the project you can click on this link.
http://s112.photobucket.com/albums/n186/AB_Summit/Snowmobile project/
As I said, I'm considering building a 2 place airplane from plans. The aircraft I am leaning towards is the Zenith STOL CH-701. To me the advantages are it's all metal, meaning storage and maintenance costs will be low, and it appears to be quite simple to build, and plans are available for it.
The only big downside to the 701 is the high cost of the Rotax 912, so I've been looking into alternatives to the 912. From looking around on the net, I have seen quite a few different kinds of engines installed in the 701, here are the alternatives I have come up with:
a)the Rotax 582
Pros: great power to weight ratio would give good useful load, cheap to buy, already comes with a redrive, so no engineering/conversion required, motor mount/FWF is available from Zenith.
Cons: two stroke, so reliability is questionable, high fuel consumption, TBO only 300 hours, would need careful attention to jetting, EGT's, etc to be semi-reliable, a little low on horsepower.
b)GEO/Suzuki 1.0L or 1.3L
Pros: cheap to buy, good fuel consumption, cheap to rebuild, can have EFI
Cons: heavy, would cut into useful load, needs aftermarket redrive, need to fabricate/engineer motor mount/FWF/cooling system, etc.
c)Subaru EA81 or similar
Pros and cons similar to Suzuki but I think the Subaru engine is even heavier so useful load would be minimal.
d)Continental 65 horsepower
Pros: simple, reliable, familiar to aircraft mechanics, no liquid cooling required, motor mount available from Zenith, good fuel consumption.
Cons: heavy, low useful load, might be short on horsepower.
e)VW conversion w/redrive
Pros: cheap compared to 912
Cons: heavy, low on horsepower
f)Corvair
Pros: cheap compared to 912
Cons: too heavy for 701, useful load would be low, performance would not be great due to direct drive.
g)HKS 700E
Pros: cheap compared to 912, lightweight would give good useful load.
Cons: short on horsepower at 60HP.
h)my own home-brewed design: what I'm thinking of doing is taking a Yamaha 4 stroke, 4 cylinder snowmobile engine and adapting a Rotax C gearbox to it to get the RPM's down to where they are usable on an airplane. This engine weighs 118 lbs dry and puts out 140 to 150 HP at 10,500 rpm. I would derate it for aircraft use and limit the RPM to maybe 7000 or 8000, but I think the horsepower would still be over 100. With the weight of the redrive and coolant/oil etc, I think the weight would be slightly more than the 912 but not by much, I would estimate the installed weight at maybe 150 lbs.
Pros: performance could be equal or better to 912, cost much cheaper than 912, good fuel consumption, decent useful load, cheaper to rebuild.
Cons: a huge amount of engineering required (attaching the redrive to the engine, designing an engine mount, cooling system, etc.), unproven design, unknown reliabilty
That's about all I can think of, other than a few other 2 stroke engines that would be similar to the 582 - Hirth, Simonini, MZ, etc.
I'll be using this plane for exploring the great outdoors - scoping out snowmobiling areas, checking out canoe routes, scouting for game, etc. so reliability and useful load are important. I want it to be reliable enough to fly into a remote area without worrying about a mechanical failure, and I need enough useful load to carry a reasonable amount of survival gear.
Am I better off saving up for a while longer and going the proven, factory supported route of the Rotax 912? Or would one of the above mentioned alternatives acheive the same goal for less money? I've pretty much ruled out the Subaru and the Corvair due to useful load considerations, but what are your thoughts on the other options?
Thanks in advance for your input,
Randy
I'm quite new to this forum, I posted once before inquiring about plans built 4 place aircraft. However I'm on a fairly tight budget, and after thinking about it for a while I think that the cost of an engine for a 4 place airplane, and the operating costs for a 4 place airplane will be too high for my limited budget. So now I am considering 2 place aircraft.
Let me tell you a bit about myself. I'm not a pilot yet. I was taking flying lessons a couple of years ago, but then I had a snowmobile accident and had to put my lessons on hold and I haven't resumed them. I've got about 25 hours in a C172 and a Citabria though. I've always been interested in planes and aviation and it's always been my dream to have my pilot's license and my own plane. I'm a born experimenter, I love fabricating things and doing things differently than most people, which makes homebuilding a natural fit for me. To give you an example, I basically built my own snowmobile (I used mostly off the shelf parts though), installing every rivet and bolt myself, and then added an automotive turbocharger to the two stroke engine. This involved redesigning the fuel system, exhaust, intake system, ignition, and installing a pressurized oil system to lubricate the turbo. If you're interested in seeing pictures of the project you can click on this link.
http://s112.photobucket.com/albums/n186/AB_Summit/Snowmobile project/
As I said, I'm considering building a 2 place airplane from plans. The aircraft I am leaning towards is the Zenith STOL CH-701. To me the advantages are it's all metal, meaning storage and maintenance costs will be low, and it appears to be quite simple to build, and plans are available for it.
The only big downside to the 701 is the high cost of the Rotax 912, so I've been looking into alternatives to the 912. From looking around on the net, I have seen quite a few different kinds of engines installed in the 701, here are the alternatives I have come up with:
a)the Rotax 582
Pros: great power to weight ratio would give good useful load, cheap to buy, already comes with a redrive, so no engineering/conversion required, motor mount/FWF is available from Zenith.
Cons: two stroke, so reliability is questionable, high fuel consumption, TBO only 300 hours, would need careful attention to jetting, EGT's, etc to be semi-reliable, a little low on horsepower.
b)GEO/Suzuki 1.0L or 1.3L
Pros: cheap to buy, good fuel consumption, cheap to rebuild, can have EFI
Cons: heavy, would cut into useful load, needs aftermarket redrive, need to fabricate/engineer motor mount/FWF/cooling system, etc.
c)Subaru EA81 or similar
Pros and cons similar to Suzuki but I think the Subaru engine is even heavier so useful load would be minimal.
d)Continental 65 horsepower
Pros: simple, reliable, familiar to aircraft mechanics, no liquid cooling required, motor mount available from Zenith, good fuel consumption.
Cons: heavy, low useful load, might be short on horsepower.
e)VW conversion w/redrive
Pros: cheap compared to 912
Cons: heavy, low on horsepower
f)Corvair
Pros: cheap compared to 912
Cons: too heavy for 701, useful load would be low, performance would not be great due to direct drive.
g)HKS 700E
Pros: cheap compared to 912, lightweight would give good useful load.
Cons: short on horsepower at 60HP.
h)my own home-brewed design: what I'm thinking of doing is taking a Yamaha 4 stroke, 4 cylinder snowmobile engine and adapting a Rotax C gearbox to it to get the RPM's down to where they are usable on an airplane. This engine weighs 118 lbs dry and puts out 140 to 150 HP at 10,500 rpm. I would derate it for aircraft use and limit the RPM to maybe 7000 or 8000, but I think the horsepower would still be over 100. With the weight of the redrive and coolant/oil etc, I think the weight would be slightly more than the 912 but not by much, I would estimate the installed weight at maybe 150 lbs.
Pros: performance could be equal or better to 912, cost much cheaper than 912, good fuel consumption, decent useful load, cheaper to rebuild.
Cons: a huge amount of engineering required (attaching the redrive to the engine, designing an engine mount, cooling system, etc.), unproven design, unknown reliabilty
That's about all I can think of, other than a few other 2 stroke engines that would be similar to the 582 - Hirth, Simonini, MZ, etc.
I'll be using this plane for exploring the great outdoors - scoping out snowmobiling areas, checking out canoe routes, scouting for game, etc. so reliability and useful load are important. I want it to be reliable enough to fly into a remote area without worrying about a mechanical failure, and I need enough useful load to carry a reasonable amount of survival gear.
Am I better off saving up for a while longer and going the proven, factory supported route of the Rotax 912? Or would one of the above mentioned alternatives acheive the same goal for less money? I've pretty much ruled out the Subaru and the Corvair due to useful load considerations, but what are your thoughts on the other options?
Thanks in advance for your input,
Randy
