david mccandless wrote:
Hi Paul, I've made contact with Don Dunbar, we are in the same club, he
knows my Stinson,his friend shares my hangar but I've not yet met Don;
it would appear. Anyways, Don thinks that I might achieve my 120HP/260
lbs by using a 88 series 4,turbo,(hi torque-3000) with no redrive.I
spoke to my prop man, he has made a successful prop (200mph) for a O200
turning 3600rpm in a Cassutt, so 120HP/ 3000-3500 for the Wankle should
OK. He thinks that he can do me a 2 blade prop to handle these
parameters, with a narrow cowl behind the the spinner, so we can run a
60" dia prop with a wide chord. I'm shying away from the single rotor
idea after comments on this web site; seems that dropping just a rotor
and an alum rotor housing plus a bit of E shaft does not lose much
weight.
Problem is, I can't see how I can just hang a prop on the end of the
engine with no support, and anything suitable would end up pretty much
the guts of a redrive. Have I got the picture or am I missing something
here ? Request your comments., ref torque and HP 3000-3500, and anything
else you might see. I can't believe I'm the first to think of this.
I have enjoyed reading your analysis on cooling requirments and I think
I now have a much better appreciation of the problems and solutions, and
I feel it can be handled. Previous to this I had little confidence in
beating the Wankle cooling problem for aircraft, after reading tales of
woe in Contact down the years. You will have noticed that I prefer the
name Wankle, I think that we should give credit to the genius who
designed it, and besides " rotary' was the name given to an ass-
backwards radial, hardly fitting the jewel we all admire. Cya,Dave McC
Hanging a prop off the engine appears to be no problem.
You might have problems with the prop thrust.
Perry Mick is running into that lately. You may have to beef
up the thrust bearing. Here is a the HP curve for a 90 turbo.
Almost the same as the 88 turbo engine.
Paul
Is there any advantage in using a smaller turbo
here to get the boost higher earlier,then run out of puff sooner to
delete the wastegate? DMcC
Yes for direct drive.
The stock turbo is smaller and does that already. You might
try a bigger compressor section to enhance that feature as acceleration
is of no concern. I could be wrong but rumor has it TO3 parts may fit.
It also has a built in waste gate which also helps.
Paul Lamar
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