Keith Wood wrote:

Okay, time for more wargaming.

Which would you guys pick, the Rotamax one-rotor, or a one-rotor conversion of a 13B, and why?

I'm leaning toward the Rotamax (for weight and for the less-experimental nature of buying a whole, running engine), but I HAVE a 13B that is most of the way through an overhaul, and could be made into a more-powerful one-rotor for half the cost of the Rotamax.

. . .what I REALLY want is for the Rotamax guys to loan me one to do extensive flight testing on my ultralight, but I'm not holding my breath . . .

Keith Wood

I agree but there is yet to be a gear box available for the Rotamax. As soon as that
happens it should be viable option. Are you willing to build a gar box or belt
drive? If you are they might loan you one.

> Paul Lamar

I'm figuring that it would be simple to make an adapter for existing
gearboxes.  My Notax has a factory-made adapter between the Provision 3
engine and the Provision 4 gearbox.

I'm also trying to find a belt-drive unit and solve all the problems at
once.

Keith

Richard Sohn adapated a Rotax or some other 2 cycle engine gear box to a
one rotor and has some bench test hours on it.
Richard Sohn <unicorn@gdsys.net>

Eric, get in touch with this guy. He can help you out real quick.

-- 
Paul Lamar ...No rotor no motor.

hi  all,    i have a couple single rotor OMC engines and have spent considerable time studying them.  i have modified one but have not aquired an airframe to try it on. this is the engine where Moller and Rotamax began.  i feel it is no contest, the mazda will deliver much more power without failure because of the oil cooled rotors.  the charge cooled rotor will never be able to deliver the power without overheating. like all aircooled engines , there is a definet ceiling, with the mazda we have not found it yet.  that is one old A&Ps opinion,  wyo. walt.

The Rotamax is water-cooled.

Keith Wood

Not the rotor. Walt is correct the rotor is charged cooled.
http://rotarynews.com/node/view/667
http://www.freepatentsonline.com/6325603.html
http://www.patentstorm.us/patents/6325603.html
http://www.wipo.int/pctdb/en/wo.jsp?wo=2000036286

Wankel Gmbh Germany also used a charged cooled rotor.
I also think Sachs used one as well.

Paul Moller mentions it in this pdf.
He also mentions turbo compounding but he dismisses it
as not practical because of the need to reduce the RPM
of the turbo charger turbine from 200,000 to 5,000 RPM.
He was off on his turbine speed by a factor of two.
On a Mazda sized engine the turbo charger turbine speed is only 100,000 RPM.
Not a problem if a friction drive is used. Friction drives
with 100,000 RPM are available off the shelf.


Keith is your ultralight flying at the present time?