Got an email from Poul Woelfle on their new ultra lite
rotary engine. PL


"We have in the meantime finished our single-rotor aircraft engine, and we
are just speaking to the first customers. Since Rotax has apparently stopped
production of the 447, it seems that its a good time to enter the aviation
market. Attached you find a data sheet of the engine.

The main objective for now was to make it run well, and it does that. It
starts with a 3Ah battery and has clean idle (slight torsional vibration
with a propeller due to the belt drive). The throttle responsiveness is also
good since we replaced the vacuum actuator for the direct intake (P-port)
with a mechanical device that only opens on the last ¼ of carburettor
opening. Also (as suggested by a Paramotor customer in France) we made the
V-belt pulley auto-ventilated, and this has eliminated any heat issues we
have had with some belt types. A customer in England has flown the engine in
this final design and is really excited about it.

Also fuel consumption is not the best
in the world, but compared to 2-stroke data I could find, we seem to be
doing quite well. I can also send you a CAD file of the engine if you want
to see the outside dimensions.

We would be curious to hear your opinion and of course any criticism or
suggestions for improvement.

Best Regards  also from my father,

Poul

Poul Henrik Woelfle

Woelfle Engineering GmbH

Randstraße 109

D - 47804 Krefeld
Tel. +49 2151 151020
Fax +49 2151 151019
www.woelfle-engineering.com
HRB 7369, Amtsgericht Krefeld
Geschäftsführer: Paul A. Woelfle


Thanks Poul,

Sounds great and please send the CAD dwg.
The fuel consumption is not an issue for ultralights
in this country and Canada as they are only used maybe once a
month for a couple of hours of low and slow recreational flying.
It is about 20% lower than a 2 cycle however.

All rotaries have a certain amount of torsional vibration.
Your upcoming two rotor will be even smoother.

I suggest you use the ceramic bearings and up the  take off
RPM and HP for five minutes. Typical of all aircraft engines. I think
customers will be more impressed with higher HP and you will sell
more engines.

When I get this multi-strike CD ignition system finished I'll ship
you one and you can test it on the dyno to see if it improves
the BSFC.

Paul Lamar