Paul,

We are getting closer to testing Steve Beckham's engine on our dynamometer
and we want to make an engine mounting system that can accept either a 13B
or a 20B, and be independent of mounting systems used for specific
airframes.  Our present thinking is to use a 7/16 in steel plate mount
somewhat similar to the Cozy Girl but with additional length and ears for
the 20B.

We have two questions:

1.  Do you have the hole centers for the Cozy Girl's plate?

2.  Which Barry mount are you currently recommending?

Thanks,

Philip Groelz

The Cozy girl mount is missing a few critical tubes. Plus it is oil leak
central :) Twice the opportunity for oil to leak out of the sides of
the oil pan. Plus all the engine oil heat goes directly into the rubber
bushing
that are only rated for 200 F. A steel plate will mitigate this last
problem
as it does not conduct as much heat as aluminum. SS is best in
that regard. Motor mount weight is not an issue for a prop dyno mount.

Make the SS plate several inches wider than the engine to get the rubber
bushings
out and away from the oil and the exhaust.

Be that as it may I understand why you can't just use Jeff's plate mount.
You are running the PS  internal spur gear PSRU and Jeff's plate won't fit
that. There are not a lot of other choices. You could use the stock 2nd
gen
center mounts if you could find a pair in a junk yard someplace. Rather
unlikely
for a three rotor.

I like the 22000 series Barry Controls $5.95 rubber bushings. I just
uploaded a bunch
of stuff on those. If you lost it let me know and I will upload it again.

Paul Lamar



I appreciate the comments.  I wasn't aware of the 200 F limitation on
the Barry mounts.  But with heat shielding from the exhaust it seems
they would last for a couple of hours, and the replacement cost is
reasonable. We should be able to learn quite a bit during each hour of
running, and leaks that would not be tolerable in an airplane should be
only a nuisance on a dyno.

I'm inclined to proceed.

Thanks,

Philip