X-Mozilla-Keys:                                                                                 
Bill Freeman wrote:

Bill Freeman wrote:

   **** SNIP ******

Show me any other intermittent combustion  engine that can generate
730 HP out of 200 pounds of engine weight. (With the exception of
the pulse jet :-))

Paul Lamar

Probably correct, but for how long?  Also the pulse jet has *very*, very,
VERY, poor BSFC.

Bill

I keep waiting for Tracy to report on his 800 hour rotary
now out of his airplane. How about it Tracy?

Paul Lamar

I don't think Tracy is getting 730 hp out of his. ;-)  I expect
that the primary problems with Tracy's motor over the
long haul will be in the PSRU and in undiscovered but
probably solvable minor issues of fuel and lube delivery.
OTOH, it is pretty clear that he has a pretty darned good start
on a safe and reliable powerplant.

What is his FWF wt and how does it compare to a
equivalent Lyc/Cont ??  My guess is that you still have
to eat a 40 to 100 lb wt penalty, but it probably is
somewhat cheaper to buy and probably significantly
cheaper to own.

Bill

Tracy has a new PSRU of his own design Bill.
His FWF is about 320 pounds. About the same as a O-320 O-360 Lyc.

If you pump the rotary up to 250 HP it beats the heck out
of any NA aircraft engine as far as power to weight ratio.

The Ross has been recently re-designed so it should be good for
at least 1000 hours maybe more. Many people have many hours on
Ross PSRU's. Only recently has it become widely known about
the sun gear thrust problem.

Paul Lamar
 
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