The other major

contributor is the sonic waves in the exhaust caused by the

rapid

opening of the

peripheral exhaust ports.

This may make some cringe, but here goes: what if a small amount of

'ramp' were put in the wall just ahead of the port to allow some gas to
begin exiting, or an inverted V notch. Not enough to make a noticable

change

in the exaust timing but just enough to take some of the "pop'" out of

the

pressure wave?

You are right on target Chrissi.  This is precisely what Mazda did in

the

normally aspirated rotary.

Same situation as a two-cycle engine.
Engines with exhaust ports that have a straight roof dump a very strong
pressure wave into the expansion chamber. Great for power output, but REAL
tough on rings.
Engines with exhaust ports that have an arched roof dump a weaker (but
longer duration) wave. Ring life is greatly improved and exhaust note much
less harsh. Quieter engines and longer apex seal life may be possible with
just a little work with a die grinder.

Larry Wiechman

 
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