Subject: powersport accident... exhaust flange.

Everett Hatch came up with this idea about six years ago.
Gives the exhaust tube the ability to move around on the spherical
joint as it heats up and cools down.
I am not sure why Power Sport abandoned it.
With an NC lathe these things can be knocked out likity split.
Power Sport has plenty of NC lathes.
No spring in the world would stand up to the heat so the
four retaining bolts should just be finger tight and safety wired.
A couple of these would be a lot lighter than the big hunking
Racing Beat exhaust flange.

Paul Lamar

Nice design, but I can see a spit forming between the two pieces

where

they clamp and the extension protudes. Just a guess. I would like to

see

those tested! Then lets turn them out of stainless on a production
basis!
[Marc Wiese]

They will split only if they lock up. Keep them loose.

Paul Lamar

If they reach 1700F and expand differentially won't the clearances
diminish somewhat? You would need to calculate the expansion rates of
all the materials. I know slip joints in regular aircraft turbo pipes
made of ss expand and seal well, but they are very simple non mechanical
joints. The Powersport design somewhat limits the movement in most
directions with the clamps.
[Marc Wiese]

The expansion rate is pretty much the same for most steels.
It becomes a case of which is the greater force and the coeff. of 
friction between the hot parts. This does not preclude still using the
traditional slip joint down stream.

Continental had a lot of problems along these lines with this engine
and it has a bunch of slip joints.
 
Paul Lamar
 
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