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



Gene,  The gilmer belt pulleys are used on blowers (superchargers) for top
fuel cars.  I got them from Weiand.  The 14-71 blowers pull about 550 HP on
these belts. Get the round tooth style good for 11,000 RPM if you drill a
series of 1/16 holes in the roots of the teeth to let air escape. You can
get them on e-bay if you search for  "weiand replacement supercharger
pulley"  or go to
www.dyersblowers.com  or hampton blowers among others. To get up to 3 to 1
ratio you could  possibly do a double reduction or call weiand and see if
they will give you a source for the larger pulley. They also sell the
matching belt tensioner.
        Reguarding Hurley's 6 rotor no reason it wouldn't run a few seconds
at a time for drag racing but useing stock 3-rotor center housings coolant
is pretty much tied to series cooling. You could weld water flanges on the
housings, however the oil fill and stationary gear drain gallery devides the
housing in two. If you introduce coolant in housing 3 or 4 the only place it
is going is the end housings. There are the stock water inlet and outlet on
the accessory end but getting the coolant out of the rear housing doesn't
look doable.
      Full length tension bolts  are also a poor idea due to length changes
with temperature. Mine go three rotors  which is why the engine is in two
modules. In addition there are four 5/8 tie rods through everything.  The
idea of a heavy base plate is workable or a composite structural brace like
the lemans 4 rotor. I  however am opting for a full length oil pan which
will be much more rigid and allow a single baffled sump for the oil. The
bottom of the sump can also be rounded to match the shape of the bottom of
the cowl. It seems like adding some cooling fins to the pan will be good
bang for the buck weightwise. My airframe design allows a bed type mount off
both ends which is a lucky thing because with an engine 5 five feet long
there is no way to triangulate a tubing structure around it.

george grimes