Subject: your opinion
From: "rotaryeng@earthlink.net" <rotaryeng@earthlink.net>
Date: 4/29/2016, 10:49 AM
To: A10-me-earthlink


 Hi Paul,

 As far as I know, Rotamax rotary engines do not have any oil sump,
 they work with oil direct injection. In your opinion, is that a good
 thing or not? Would you recommend oil sump or oil direct injection?
 I am looking to get 350 Hp out of a 2 Rotor engine, in all aluminum.

 please see following picture of a Rotamax engine.

 http://www.indysportaviation.com/Oshkosh2008/rotamax120hp.html


 Thank you Andy Mangold

 It is called charge cooling and it is inadequate for an aircraft
 engine called on the generate over 50% power for long periods of
 time.

 You will need a high pressure oil system with oil cooled rotors. In
 other words a Mazda.

 Paul Lamar

 Paul, Thank you very much for the info. I am planing to run the two
 engines only on 50%, even for take off. Only in case of emergency,
 when one engine is failing, the remaining engine has to go up to
 100, but only for about 5 minutes. In a case like that, would you say
 it is OK?

 Andy Mangold

 Good luck. Might work.

 The rubber coupling they used also failed causing a crash.

 Paul Lamar


 The charge cooled rotary engine and the 2 stroke piston ignition
 engine seem to suffer the same defects : - low fuel efficiency, -
 large amount of oil in exhaust gas, - not suitable for high charge
 base load operation. - not suitable for turbocharging (and
 turbocompounding, of course)

 and also share some good points : - simpler and lighter than their
 counterparts, - automatically lubricated in any position.

 So they are suitable for the same applications that require low
 power for limited time and high peak power to weight ratio as RC
 models, chainsaws,...

 Philippe Dejean (France)


 Guys. thanks for all the info.

 Does anyone know the weight difference between an all aluminum two
 rotor engine and a engine with iron cast side housings?

 Also does anyone know if I can mount the two rotor engine just on
 the Bell Housing?

 Andy Mangold

 The bare cast iron Mazda weighs 190 pounds. The bare all aluminium
 Mazda weighs about 110 pounds.

 It is possible to mount it with the bell housing but probably would
 require some tig welding on the bell housing. Send me a sketch of
 what you have in mind.

 Do you have a gear box?

 Paul Lamar



 Again thanks for the info.

 About the mount, you can see two PDF drawings in the attachment.

 I do not have a Gear Box. I could mount the engine right at the front
 of the Block. The engine will be hooked up direct to the drive shaft
 with a flex coupling between. Then the driveshaft goes on to a center
 gear with a reduction for the propeller. The same on the opposite
 side. The drawings are with the Rotamax engines and those have
 mounting points on the belly and on the top.

 That is the reason why I am asking, if I can mount them just on the
 front/ to the Block on the Shaft side. That strange form around the
 engine is made out of carbon fibers and serves as Engine mount and
 also for the landing gear, which you can not see on these drawings.

 Andy

 That will work but you only need two rubber bushings on that end of
 the engine. One on the other end. That is all you need to locate an
 object in space. The two rubbure bushing react the torque from the
 engine.

 Read this.

 Hi Paul, As far as I know, Rotamax rotary engines do not have any
 oil sump, they work with oil direct injection. In your opinion, is
 that a good thing or not? Would you recommend oil sump or oil direct
 injection? I am looking to get 350 Hp out of a 2 Rotor engine, in all
 aluminum. please see following picture of a Rotamax engine.
 http://www.indysportaviation.com/Oshkosh2008/rotamax120hp.html Thank
 you Andy Mangold It is called charge cooling and it is inadequate for
 an aircraft engine called on the generate over 50% power for long
 periods of time. You will need a high pressure oil system with oil
 cooled rotors. In other words a Mazda. Paul Lamar Paul, Thank you
 very much for the info. I am planing to run the two engines only on
 50%, even for take off. Only in case of emergency, when one engine is
 failing, the remaining engine has to go up to 100, but only for about
 5 minutes. In a case like that, would you say it is OK? Andy Mangold
 Good luck. Might work. The rubber coupling they used also failed
 causing a crash. Paul Lamar The charge cooled rotary engine and the 2
 stroke piston ignition engine seem to suffer the same defects : - low
 fuel efficiency, - large amount of oil in exhaust gas, - not suitable
 for high charge base load operation. - not suitable for turbocharging
 (and turbocompounding, of course) and also share some good points : -
 simpler and lighter than their counterparts, - automatically
 lubricated in any position. So they are suitable for the same
 applications that require low power for limited time and high peak
 power to weight ratio as RC models, chainsaws,... Philippe Dejean
 (France) Guys. thanks for all the info. Does anyone know the weight
 difference between an all aluminum two rotor engine and a engine with
 iron cast side housings? Also does anyone know if I can mount the two
 rotor engine just on the Bell Housing? Andy Mangold The bare cast
 iron Mazda weighs 190 pounds. The bare all aluminium Mazda weighs
 about 110 pounds. It is possible to mount it with the bell housing
 but probably would require some tig welding on the bell housing. Send
 me a sketch of what you have in mind. Do you have a gear box? Paul
 Lamar

 Again thanks for the info.

 About the mount, you can see two PDF drawings in the attachment.

 I do not have a Gear Box. I could mount the engine right at the front
 of the Block. The engine will be hooked up direct to the drive shaft
 with a flex coupling between. Then the driveshaft goes on to a center
 gear with a reduction for the propeller. The same on the opposite
 side. The drawings are with the Rotamax engines and those have
 mounting points on the belly and on the top.

 That is the reason why I am asking, if I can mount them just on the
 front/ to the Block on the Shaft side. That strange form around the
 engine is made out of carbon fibers and serves as Engine mount and
 also for the landing gear, which you can not see on these drawings.

 Andy Mangold

 You only need 2 rubber bushings on one end of the engine. You need at
 least one on the other end. Otherwise there will be a lot of bending
 on the plate.

 I am curious. Where did you find 2 rotamax engines?

 Is it a one rotor or two rotor?


Paul,
coming back again about all aluminum rotary. Is an all aluminum two rotor
engine with oil cooled rotors suitable/doable to be turbo charged with up
to 10lbs pressure and producing about 350Hp? And is a configuration like
this still reliable?

Andy Mangold

Are you kidding? :-)    Where have you been? :-)

Try 650 HP.

Haven’t you heard about our time to climb project?

Yhe turbo compound rotary is going to replace the small
turbo prop engine.

Paul Lamar


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