OK Jerry and Blake here is the plate dimensions from the horses
mouth. Tracy kindly printed the drawing and I scanned it in at 500 pixels
to the inch when I got home. You will need a good viewer or printer to read the fine print. 
If this is still not good enough I can scan it in at 600 or more pixels to
the inch.

Just to set the record straight it is better to mount the engine using
this plate as the motor mounts ultimately react the 400 ft pound avg. prop torque pulses.
The engine puts out two hundred foot pounds avg. and the gear box doubles it.
If the motor mounts are fastened directly to the engine they see the
prop torque pulses through Tracy's spacers and long bolts increasing the deflections.

The only case where this is not true is if you drop it in on a six
G crash and then the spacers see less vertical shear load but not much.
That is probably a once in a life time landing and then the
load is only for a fraction of a second. The torque pulses on the
other hand are day in and day out.

BTW I highly recommend estimating the weight of your motor mount design.
Aluminum weighs .1 pounds per cubic inch and steel .3 pounds per cubic inch.
Four inch longer .049 wall 3/4 diameter tubes weigh very little.

A 3/16 thick steel oil pan sandwich plate 16 inches by 16 inches on the other hand 
would weigh 14.3 pounds with no holes. A 3/4 inch diameter .049 wall tube 
4 inches long would weigh .14 pound. Six of those would weigh .84 pounds.

Does everybody understand this? Am I being clear?

Paul Lamar
 
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