I would not put too much credence to a six rotor. The output shaft on
 the last rotor is not getting any larger. My guess is 5 rotors is pushing
 it.
 Emon Hurley built one years ago.

 Paul Lamar

 I am new to this board, but I see a topic of interest to me, I am looking
 for 1200 HP to 1600 HP output from an engine thats not a turbofan, insert
 cost of said type jet engine.  I note that that Emon Hurley built a six
 rotor:

 1) was it a success?
 2) what HP output was achieved?
 3) did Emon use two mazda engines joined with a modified,
    machined output shaft with six lobes? sans not having to
    manufacture from scratch...
 4) did he have to produce new end bearings to handle the
    torque?
 5) could this six rotor engine handle compounding as you have
    spoke of?
 6) can a different number of rotors deliver 1200 to 1600 HP
    without extreme over speeding for V/STOL aircraft
    application? sans produce 1200 to 1600 HP for takeoff &
    landing...

 GFCurtis Jr.

 From the looks of the side port intake manifold my guess is 100 HP per rotor
 max. Emon said he was serious but I don't know if it ran under full load
 as I saw no dyno in his shop. He builds his own e-shaft couplings.

 The p-port four rotor NA is only good for about 700 HP.
 If you boost it to 1600 HP or 400 HP per rotor the e-shaft may
 fatigue and break just shy of the flywheel.

 The safest way is to use two three rotors or two four rotor engines with
 the power combined into one larger shaft so the e-shafts will not be over loaded. Wankel Gmbh built a four rotor using that trick.

 Better yet use two props as the total prop disk area controls the static thrust.

 Any engine could be compounded.

 The Mazda engines are good to about 11,000 RPM with cast iron
 rotors. If you make the rotors out of BeAl alloy they would be good to almost
 20,000 RPM with near twice the power. A single large diameter turbine
 mounted directly on the E-shaft would be all you need to compound
 it. No gears. No couplings.

 Paul Lamar


Where can I get my hands on those nice belts and sprockets?  They
Look about perfect for some future PSRU...or even the ones used by
Mr Hurley?

Gene Kahn


Unfortunately I think the sprockets were custom made.
I know Ken Welter built his own. Ken put as much as 300 HP
through these for just enough seconds to get the Coot
off the water.

I have not been able to find a source for aluminum versions.

Harley Davidson motor cycles have 2 inch wide rear aluminum sprockets
so you might be able to stack them.

Paul Lamar