I think what we really need for the torque damper is a fliud
coupling. I was at the Camarillo air show yesterday and they had
an unprecedented collection of war birds. No less than two flying
P38's among many others.

They also had a restored early Northrop flying wing.

I turned the prop both ways  and it rotated freely.
I asked some of the CAF types if it flew in :)
They said yes. They said it had torque converters but
what I really think they meant were fluid couplings.
Maybe they were really torque converters Northrop got in a
junkyard :)

The torque converter is closely related to a fluid coupling
and is widely used in automatic transmission. The stall
speed is about 2000 RPM so the engine can rotate freely
up to about 1500 RPM before a lot of torque is transmitted.

Our problems are not so much torsional resonance but
gear box chatter.

I think a fluid coupling will solve the problem once
and for all.

http://pt.rexnord.com/products/couplings/true_torque_fluid_couplings/fluid-couplings.asp

Falk True Torque Fluid Couplings

A fluid coupling allows the motor to accelerate independently to full speed,
the driven load has been isolated by the fluid coupling.

Paul Lamar

       
So would an automotive torque converter be suitable? At least the mass would
give you some desirable flywheel effect:) The fluid fly-wheel would have
more chance of dissipating heat build-up than those poor little bits of
rubber!
What about the prop now free-wheeling to give windmill drag with the engine
out?:(


John Evans
          

Probably weigh 10 or 12 pounds. On the up side if you used the Mazda auto tx
torque converter it would bolt right up to the stock flex plate :) Ironically the
Mazda auto tranny is a scaled down version of the Ford C6, A4OD, etc., etc. which
we now use the planetary gears out of.  Made in Japan by Jatco transmission.

Paul Lamar

I wonder if something like this could be adapted for our uses...
it is another type of harmonic damper, and is not inserted
directly into the power transmission chain, but rather only
acts to dampen torsional vibrations in the same way that
harmonic balancers do...it consists of an inertial disc inside
a very viscous fluid:

http://www.thedieselpage.com/features/fluidampr.htm

Gene Kahn

It might work but it is intended to be tuned to damp the
torsional resonant frequency of a crankshaft. E-shafts don't have that
problem.

Paul Lamar