Rotary Aircraft
#4
Rotary Enthusiast
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They are actually pretty reliable.
The engines for those aircraft only need low 100hp so the engines are de-tuned and they only rev to about half what they do in a car. They are actually pretty popular...low weight, no vibration, etc.
Chris
The engines for those aircraft only need low 100hp so the engines are de-tuned and they only rev to about half what they do in a car. They are actually pretty popular...low weight, no vibration, etc.
Chris
#7
The rotary is great in an airplane. They run a gear reduction unit to keep the prop speed low. I'm not sure but I think they are 2:1 so the engine runs about 5K. Besides the accessories outside the engine the biggest common problem would be losing an apex seal. If that happens you still have 2/3 the power (or 1/2 the power with two seals on one rotor gone). Figure that plane will stay airborn with about 35hp(maybe even less) and you can find an airport pretty easy in a plane that still wants to fly.
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#13
nor-cal
I'm up in the SF north bay.
Currently the engine mount is on the firewall, engine is built but none of the systems are in.
Once I get the cowling everything will start coming together.
Currently the engine mount is on the firewall, engine is built but none of the systems are in.
Once I get the cowling everything will start coming together.
#14
forgot... it's on a Van's RV-7. Two place low wing. Find them at www.vansaircraft.com
#15
Paul's site.
#16
The rotary is great in an airplane. They run a gear reduction unit to keep the prop speed low. I'm not sure but I think they are 2:1 so the engine runs about 5K. Besides the accessories outside the engine the biggest common problem would be losing an apex seal. If that happens you still have 2/3 the power (or 1/2 the power with two seals on one rotor gone). Figure that plane will stay airborn with about 35hp(maybe even less) and you can find an airport pretty easy in a plane that still wants to fly.
i have no idea why people use that as an excuse to run these engines in aircraft anymore, i used to agree until i thought about it. even in limp mode it would barely carry the weight of a light craft at altitude for long as you then have to push the engine to maintain and also use twice as much fuel over the same distance so hopefully you aren't mid atlantic when it happens or have a way to cut fuel to the offending rotor.
Last edited by RotaryEvolution; 06-14-12 at 07:38 AM.
#17
Banned. I got OWNED!!!
iTrader: (11)
i dont think that many people try to cross the atlantic in single engine prop planes anymore. 1/4 the power available is still better than 0/4 available and if you have a failure, its not like you are just going to continue on your merry way. most light aircraft trips are 2-3 hours? and puddle jumpers so in reality, youre never far from an airport or somewhere appropriate to stick the plane unless you live in the klondike.
#18
true, just don't want people getting the wrong impression from these motors. yes a single seal failure is quite a bit more desirable than losing a whole rotor but they still both cause power to nosedive quite heavily.
try racing a 35hp volkswagen bug when you lose a rotor, vw would win... lol
try racing a 35hp volkswagen bug when you lose a rotor, vw would win... lol
#19
I've lost seals on the street and during races. The engine pretty much will run until it is shut off then never start again. Any power is WAY better than no power when it comes to trying to stretch a glide. It's all about time and altitude when you have a problem in the air. 35-40hp will buy you a lot of time.
Just keep flying, hit the NRST button on the Garmin and see how far the closest airports are and declare PAN-PAN on the radio.
Just keep flying, hit the NRST button on the Garmin and see how far the closest airports are and declare PAN-PAN on the radio.
#20
piston engined airplane engines have been known to fail too
it's just more spectacular to have a crankshaft fail or a valve or valve seat to lunch. Jugs separate, con-rods fail... many more parts. Why do I have to even say any of this stuff. ![scratch](https://www.rx7club.com/images/smilies/scratchhead.gif)
I know that an o-360 is meant to run all day long at 75% power and it doesn't have any extra systems to fail, no coolant to lose, no external power required to continue running and no electrical driven fuel pump. no gear reduction drive.
I just want to put this engine in, I'm already committed. How about some words of encouragement or some tips for longevity or reliability.
I don't know.
![scratch](https://www.rx7club.com/images/smilies/scratchhead.gif)
I know that an o-360 is meant to run all day long at 75% power and it doesn't have any extra systems to fail, no coolant to lose, no external power required to continue running and no electrical driven fuel pump. no gear reduction drive.
I just want to put this engine in, I'm already committed. How about some words of encouragement or some tips for longevity or reliability.
I don't know.
#21
Don't fret Bill, these guys understand all the things that will go wrong with a rotary and 95% of them have never had one apart, let alone deal with a fresh/new one. Karack has but he also hasn't thought much about everything that can, and does, go wrong with the certified engines usually hung on an airframe. Especially turbo ones if you want that kind of power.
So are you going for big power with the turbo or just normalized? I would use ceramic seals if you are looking for any kind of HP. What gear reduction unit are you going to use? My friend had issues with the first one he got and it tore up the planetary gear set. After spinning it by hand you could see how some runout caused all the trouble. What will your cruise RPM be on the engine, below 6K and the engine will last a looooong time.
I would be worried more about what you use for electronics for the injection, I haven't looked into what has been coming out in the last 5 or 6 years. Going FADEC?
So are you going for big power with the turbo or just normalized? I would use ceramic seals if you are looking for any kind of HP. What gear reduction unit are you going to use? My friend had issues with the first one he got and it tore up the planetary gear set. After spinning it by hand you could see how some runout caused all the trouble. What will your cruise RPM be on the engine, below 6K and the engine will last a looooong time.
I would be worried more about what you use for electronics for the injection, I haven't looked into what has been coming out in the last 5 or 6 years. Going FADEC?
#23
I have been an aircraft mechanic for the last 14 years. Also a Mazda rotary builder for almost 16. The chances of a Rotax engine (used in ultra lights) geting completely fucked since the oil premix fail 60 to 80 percent of the time just like a jetski. than loosing one rotor in the air and you still have 1/2 of the power to land safely. BTW. Theres nothing wrong with the propeller reduction gear box of that wankel. Not too different from a Cessna 172. Awesome project!!! Remember your engine will love AVGAS 100 Low Lead.