I found this very informative......take it for what it's worth. Adobe
 doc. Marc

http://www.autopsrus.com/

A stock Chevy V8 is unlikely to put out a constant 400 HP for more
than five or ten minutes. There have been dozens of attempts to use
Chevy V8's in aircraft over the years. All have failed.  Including
the Thunder/Orenda.

BW probably stands for Bud Warren. Bud and his daughter died in a
Chev powered airplane.

105 pounds or even 70 pounds  is ludicrous for an aircraft engine
reduction gear. Typical for a spur gear transmission.

A planetary is six times stronger for the same gear width and much
much lighter. The Ross weighs 35 pounds.

The off set is incorrect for a rotary. Makes the thrust line too low
 reducing the prop clearance.

The offset causes a gear mesh problem when the aluminum gear box
warms up and expands.

Paul Lamar


That definitley looks like a Bud Warren derivative. To be fair, Buds
 second crash, the one that killed him, was not due to gear box
failure. I believe it was a fuel line too close to the exhaust, but
that may have been the first crash.


However, there was another crash of BW gear box back on the East
Coast in a velocity or Lancair that killed the pilot.  That crash
probably was caused by the gear box.  The thought was that the using
 the clutch to dampen the power pulses and harmonics wore the clutch
 out.  When it finally stated to slip the situation quickly
deteriorated and the clutch completely wore out within seconds.
Witnesses say the aircraft was not climbing despite very high RPM of
 the engine.

David Leonard


Bud had the slipping clutch and he didn't want to damage his
beautiful plane and he tried to come back I think. Peter Duffecy

Both of Buds crashes were in Wheeler Express planes like mine. His
first was a SS oil line rupture that sprayed on the headers causing a
 fire. The 3 on board walked away. Sales of the kits went up. After
his second and fatal crash, Wheeler sales went to 0 and the company
went bankrupt.

Neither crash was due to any fault of the airframe.

Kevin Alderman

Kevin Alderman President Aviation and Avionics Services Inc.


Another sad story - both Bud and Phyllis were a pleasure the times I
talked to them.

The NTSB report mentioned:
http://www.ntsb.gov/aviationquery/brief2.aspx?ev_id=20110505X90031&ntsbno=CEN11FA324&akey=1
"The propeller speed reduction (PSRU) was removed from the engine and
examined. No preimpact anomalies were noted."

David's comment on a possible failure mode sounds plausible - higher
order resonances could still cause slip leading to failure, as could
other failures.
Did Bud ever characterize the fundamental frequencies of the engines?
the centrifugal clutch engagement could certainly be tuned.
Did the examiners even know what they were looking at/for?
Any real details?

c beazley

Experience has shown the NTSB is incompetent when investigating
experimental aircraft crashes. It is not a high prioroity with them.

I recommend static testing any gear box to double the expected
torque from the engine. In the case of the rotary a good number is 500
ft pounds. Bolt down the prop flange and apply 500 ft pounds to the input
shaft. Also have a rubber coupling in there. Rubber has the ability
to absorb torsional  vibration in the form of heat and mitigate the shock load on
the gear teeth. Silicone rubber is good for 500 F.

Paul Lamar

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