X-Mozilla-Keys:                                                                                 
Mike Wills wrote:

Mike, could you read those Barry mount dimensions OK?

Paul Lamar

Paul,

  Yes I got them. I figured that it would be easier to mock something up
with these in hand even if I dont ultimately use them. It looks like things
are going to be really tight in the vicinity of the forward exhaust port.
The mount can be a maximum of about 20 inches wide in this area. It looks
like a mount bushing with the hole aligned horizontally (as is done in the
Powersport test stand that you posted previously and in the Lyc conical
mount) will fit much more easily in the space available than will this
bushing/hat section design with the bolt hole aligned vertically. I have a
couple of pictures of Alan Tolle's mount in his RV-3 and it also uses the
horizontal bushing. The more I look the more I think this is the way I
should go. I need to get a catalog from Barry and see what other types of
bushings are available.

Mike Wills

If you have a real late engine the motor mount hard points are on the 
bellhousing endhousing. Power Sport had an intermediate engine (I forgot 
the year/s) with the motor mount hard points on the center housing.
Very early engines had the motor mount hard points on the front cover.
The hat section design will accomodate any year engine.

Stiffness of the Barry mounts changes with orientation so be careful
about that. I oriented the mounts to take the torque and G loads
with low stiffness for good vibration isolation.
The thrust loads at high speeds are moderate and or can be taken by
the rear mount oriented vertically. High static thrust during takeoff
only last for a few seconds. The ideal mount would have more rubber
between
the bolt spacer and the aluminum block. If you make your own out of
silicone rubber you would have that option.

Barry does not have a bunch of options in this regard. Most of their
mounts will only except overload in one direction. Downwards.  We need 
positive overload capture in both directions in the vertical dimension. 
Up and down. These mounts I am suggesting are the Barry exceptions. This 
is one of the things slowing me down from using the Barry pneumatic
mounts 
to make a built in dyno. I would have to provide some sort of up
vertical 
up travel limiting device.
 
Paul Lamar
 
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