Al Gietzen wrote:

I have an inconel tangential manifold/muffler on my 20 - photo attached (made by
Mark (can't remember last name), a la David Atkins).  The inconel tubes extend
through the heavy Racing Beat Flange, but are welded on the outside - not on the
inside.  Although having the tubes go through the flange may have made the
welding easier, I'd guess that once you get that weld bead around there the
resulting strength is no better then butting it up and wleding it.  Seems it
should be welded on the inside end so the flange can support the loads on the
tube. There obviously will be significant thermal stress set up and the unit
expands and the engine doesn't. Atkins has the same approach on his 13B and it
seems to be fine.  The distance between the ports is much less on his.  Am I
worried about mine?  Yep.  Short redoing a very expensive piece, I'll do
frequent inspections.

Ick.  Those short headers from the exhaust flange to the muffler are going to
crack at the muffler and/or the header.  Abel Ybarra (sp?) I think had some
Inconel bellows on his exhaust system.  If you can find *2* (not 3!) such bellows,
have the #1 and #3 rotor's headers cut out and replaced with the bellows.  The #2
rotor's header would continue to rigidly mount the muffler, and the bellows would
allow things to move.  The muffler would need a non-rigid weight support to help
prevent cantilever cracking.

I need to get Rhino so I can draw what I mean.

Russell Kent

Not necessarily Russell. If all three outlets are tied
together with a racing beat type exhaust flange it might almost 
track the expansion of the muffler.

Paul Lamar
 
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