George

I looked at the pictures you sent and you're right,  You desperately need to
strengthen the cowling fore and aft.  I wouldn't necissarily use PVC pipe
though.  It is heavy and non-structural.  I'd suggest a piece of 1/2" balsa
core (since it has great temperature resistance).  If you want it hollow to
blow some air through, tape some core down, and against the cowling, apply a
little mold release wax and lay up a piece of 282 carbon fabric, about a 3mm
coremat layer, then another 282 over that. When cured, pull off the part and
tape then bond in place.  It will be light and have stiff side walls,  Also,
always "sculpt" the pieces together.  In other words, no hard edges or
corners.  This should apply to your new stiffeners, too.  Radius the point at
which it butts against the plenum.

You should probably get some higher temp epoxy for the application, too.


Dan Newland