Subject: your opinion
From: "rotaryeng@earthlink.net" <rotaryeng@earthlink.net>
Date: 4/29/2016, 4:49 PM
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


Wow, I like to hear that, it lets my heart pump faster!

In your experience, to gain 350Hp out of a two rotor engine, how much turbo
boost will be necessary? Or is it possible to reach that even without a
turbo?
I am asking because Adam from rotaryengine.com has concerns running a all
Aluminium Engine with more than 6psi boost. For 10psi boost he would put
more studs in.

Andy Mangold

In P port form it will generate up to 300 HP at 9 or 10,000 RPM.
We are running about 25 to 30 inches of boost.
The engine is robust to say the least.

Usually people use 1/2 inch tension bolts. If you want to save weight
you can use titanium tension bolts. Check out Mazdtrix on google.

Paul Lamar


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