Mailing List Message #1459
From: Mark Steitle <>
Sender: Marvin Kaye <>
Subject: Exhaust port modifications
Date: Tue, 15 Apr 2003 12:21:14 -0400
To: <flyrotary>
I'm addressing this to those on the list with extensive rotary experience in hopes of learning some deep dark rotary racing secret.

Attached are two pictures of one exhaust port (inside and out) from my 20B.  While looking it over yesterday, I noticed a small (approx. 1/8") slot along the top of the port.  It has a diverter running lengthwise that forms the lower lip of the slot.  The slot feeds the EGR system.  My question is what, if anything, should/could be done with this to improve power?  It looks nothing like the exhaust port insert in my old (junker) '89 N/A 13B.

The second picture shows the outside view of the exhaust port, which is a rather odd shape.  The insert has a passage inside so as to prevent taking a die grinder and rounding the port.  Is this something to be messing with, or should I just leave it alone?  Does someone sell a replacement insert that will give me lots of free hp?  ;-)

Mark S.
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