I was looking at the PSRU and engine mount.  The PSRU case is
   cast to
        hold the Barry Mounts which is what has been suggested for the
   rotary
        if only we could generate the $$ to cast such a case.  Unlikely.
        What did interest me was the use of square tubing for the engine
        mount.  I believe this is possible because the upper and lower
   engine
        mounts and the Barry mounts are in the same plane  parallel to the
        engine thrust line.  In some instances we might be able to do
        something similar by adjusting the length of the S beam to
   match the
        firewall hard points if they are the same upper and lower.  One
   could
        actually fab up the the sides on the bench.  A modified version
   would
        be to maintain the firewall hard points out the the rear beam and
        then from the rear beam to the Barry Mounts, it could be
   narrower but
        still parallel to the thrust line  so that square tubing could be
        used. Probably need a gusset at the rear beam if there is off set
        between the front and rear pieces.     Now is when I need
   Rhino.  It
        would be interesting to explore the possibilities.

           I think the present rear beam or strut  engine mount is just
   about
        perfect for our application so I am not advocating a
   change.    Jerry

        -----------------------------------------------------------
        The empty weight is listed at 1800 pounds and gross is 2500 pounds.
        The engine  alone is in the neighborhood of 500 pounds. The
   chain drive
        gear box adds another 127 pounds. The prop 30 pounds. The wing
        loading is 22.5 pounds per square foot so stall, takeoff and
   landing
        speeds would be high.

        The Chevy LS2 engine is: 400 HP at 6000 RPM
        400 ft pounds torque at 4400 RPM or 335 HP.
        The last number looks about it for takeoff and climb as
        the max gear reduction is 2.22:1. That gives a prop
        RPM of  2000 I would guess. Lets see prop diameter is 86 inches.
        Circumference is therefore 22.5 feet. Mach one is about
        1100 FPS or 66000 feet per minute so prop RPM
        is 2933 RPM at Mach one tip speed. Tip drag starts getting bad
        at around Mach .7 so max RPM on this prop should be
        around 2000 RPM. The numbers check with my guess.
        It is erroneous to believe with this PSRU ratio that you will get
        400 or 500 HP out of the Chevy LS2 or any other LSx V8 engine.
        335 HP at 4400 RPM is a more realistic estimate.

        Now the question is: for how long? Back in the days when I was
        associated with GM the stock engine durability test was 300 hours
        cycling the engine between max torque 4400 RPM and 6000 RPM max
   HP.
        I don't know if the LS2 will pass that test. In sprint road
   racing our
        TBO was 2 hours. It took years of programmed dyno testing and part
        redesigns  to get the big block life up to 24 hours for Lemans
        competitive power.

        In a car the LS2 engine rarely exceeds 2000 RPM at Freeway speeds.
        First thing you need to do is throw away the cast iron or powdered
        metal rods, cast iron crank and cast Al piston and change them to
        aircraft quality forged materials such as 4340 and heavy duty
   piston
        alloy. It is not possible to use sodium cooled valves due to
        the small stem diameter so a higher quality SS exhaust valve
   material
        is needed. Then one would need a good maintenance program for
        checking for internal parts cracks every 50 hours or so after
        the first 300 hours by disassembling the engine.

        It has a real nice high pressure die cast aluminum oil pan :)

        Paul Lamar



   Somebody said 3 rotor..  I say p-port 4 rotor..  It would still be
   lighter than the V8 Chevrolet.  A 2 rotor bare block is 190-200lbs, a
   bare 3 rotor is 260lbs.  Would a bare 4 rotor be 320lbs (less?)?  The
   gear reduction would be heavier than is used for a 2 rotor, but not
   double.

   And it would be good for 450hp at 6000rpm.  With a 2.85 gear, that is
   about 2150 prop RPM.  Nice.  Easy.  Run forever.

   Can a double width carrier be easily built for a 2.85 500hp reduction
   unit?

   450hp with an installed weight about the same as a big bore continental,
   things get interesting.  How about this engine in a P210 (obviously
   turbocharged/compound to run the pressurization).  Or how about
   somebody
   knock off a C195 sized airframe.  It would be sporty.  This sized engine
   would even run a Beaver (replacing an R985).  Or how about two of them
   on an early Twin Commander airframe.  Or how about mounted on a Beech
   Duke.  Either one of those would be a nice get around..


   Matt-

   "Can a double width carrier be easily built for a 2.85 500hp reduction
   unit?"

   That is an interesting idea Matt perhaps the gears can be turned
   around to make a herringbone set canceling out the gear thrust.

   This P&W PSRU was good for 40,000 HP.

   The airplane you are looking for is a Stallion.
     http://www.aircraftdesigns.com/ <http://www.aircraftdesigns.com/>
   Here is one at SZP with a turbo prop engine.


   Paul Lamar ...No rotor no motor.



I am not a fan of anything Martin Hollmann has been involved in.


Matt-

You might have a point there :) He did a lot of consulting
on the Lancairs.