Subject: RV-4 motor mount system
From: ACRE NL
Date: 10/21/2001, 3:00 AM


         I'm not looking at using it for the motor mount at all.  That's
why I only want enough sticking out to mount the starter.  I'm going to do
the sandwich with the oil pan that includes the windage tray (keeps the
aerobatic oil displacement under control).  This will extend out the side
and rest on a bed mount I'm working on.
         I don't have any good drawings to send yet or I would.  I quickly
plagiarized one of your RV-4 mount drawings to give you an idea of what I'm
talking about.  The RV-4 has a sort of tunnel that runs forward from the
spar (F-413R & L for the RV-4 guys).  I am going to extend that and have it
widen out enough to let the engine rest on it.  It will require some rework
of the fire wall and a work around for the gear but I think when it ties
into the forward fuse it will be a little cleaner and stiffer than trying
to work with the original mount system.  It sounds complicated but as much
as I've thought about it, looked at the plans and sketched it out it really
isn't.  I'm going to try and get this CADed up this week and I'll post it
up for critique.
         Ya know, the more I look at this the more I think I should just
cut up a bell housing for the redrive mount.

Mike

Mike McGee, RV-4 N996RV, O320-E2G, Aurora, OR
13B in gestation mode


Not a bad idea. The Bonanza, Cessna P210 and the Questair Venture use an
aluminum  structural lower cowl. You will need to feed those landing
gear tube socket loads into something substantial. Where are the rubber
mounts?

 The bell housing is too deep. It needs to be 3.040 inches
deep as I recall.

Paul Lamar


         I've got two ways to go on the landing gear.  I can cut off the
cross pieces and re-mount the gear legs individually (lots of work).  Or I
can design this mount in two pieces so that it allows the landing gear
cross bars to pass through it independently.  I'm currently leaning towards
the latter.

         The rubber mounts I've dreamed up are something a bit
different.  With the engine and it's oil pan/mounting plate sandwich
setting on this tunnel, I can see simply capturing the mounting plate in a
silicone and metal sandwich along the top of the F-413 extensions.  The
silicone could be some of that orange baffle seal ribbon isolating the
metal parts from each other.  I need to draw this for it to make sense.  As
wild ideas usually go I may have to fall back on some conventional
arrangements.
         Sounds like I just need to have a plate like Tracy has on his
plane to mount the redrive.

Mike

Mike McGee, RV-4 N996RV, O320-E2G, Aurora, OR
13B in gestation mode

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