OK here is what I recommend. The 4130 rectangular steel tubing is
now use to distribute the tension load into the two
original hard points. The new lower hard point adjacent to the
lower longeron that Bill is modifying will take the lower
compression strut load. Just like Perry's original set up.

This should work fine and give plenty of room around
the right side of the engine for exhaust, intake and water plumbing.

The triangles should be braced on both sides either to the first
wing rib or forward diagonally to the spar. Your choice. There is very
little side load so this is mainly a stiffness issue so 1/4 ball
jointed 1/2 inch diameter struts could be used.

Underneath the pan and between the rubber mounts there will be plenty
of room for a 12 inch wide radiator. No diagonal tubes. The pan is
not shown but a custom aluminum pan is recommended but not required.

The front mount is not shown but any one of a number of schemes will
work as there is little or no load. The rubber bushing shown are on
or near the CG of the engine/psru/starter/alternator/prop combination.
I recommend welding something on to the front panel of the pan for
a front mount.

Paul Lamar

I like it Paul. Where those rubber bushings are, they
will have to be located right next to the engine, or
your cowling will have rather strange lines in that
area.  I think my cowling is only a few inches wider
than the engine back there.

--
Perry Mick
Duckt N7XR
http://www.ductedfan.com

Thanks Perry. A little bump here and there won't hurt.

I had another idea. Here is a picture of the inside of the fuselage
in the area that needs to be beefed up. One way is to route out some
foam and slather some carbon fiber in here. A bit brute force.

Another better way is lengthen the bolt that the landing gear pivots
on and feed the lower motor mount loads directly into the landing gear
brackets using a long spacer. This is a very fine way of controlling
load paths. The landing gear, after all, is where some of the high G
impact loads come from in the first place. This is an old idea and
I will write a little message on its historical significance and
background  shortly. I am surprised Burt did not think of it when he
designed the Long in the first place.

I will also do a sketch on the idea.

Paul Lamar


I measured the inside of my lower cowl this morning and it
is 16 inches across in that area where the rubber mounts
would go.  You wouldn't want it any wider than that.

Perry

OK Perry.

Paul Lamar
 
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