Subject: Apex seal weight.
From: Paul
Date: 2/26/2001, 8:32 PM



It was stated that Emon strongly recommends the 3 mm apex seals for

a/c >applications.  Based on that, and the desire to not have my motor
self-destruct >while aloft,  I decided that was the way to go and I signed
up for a set of 3mm >seals/springs for my 20b.  I realize that I will need
to have my apex slots ground >to accept the larger seals.  My question is
this, is this really the best way to >go, or am I just solving one problem
just to create another (higher weight & >wear), or are the 3mm seals
recommended due to their higher profit-margin?  Also, >although grinding is
the preferred method, would it be acceptable to have them >machined instead?
Finally, do you know of anyone stateside that can grind the grooves >for us?

Thanks,
Mark




I definitely think the 3 mm are the way to go. Since we run the engine

at only

6000 RPM the wear should be good for at least 1000 hours. I saw Tracy's

2 mm seals

after he removed them from his engine at about 800 hours and the wear

along the

sides of the seals was noticeably but not excessive. In any event if I

can't talk Eamon into doing it on all 3 mm seals I will make a little
drilling jig and drill mine in the drill press one hole at a time :-)


I have not gotten around to looking for an outfit that can grind the

seal

slots. Should not be too hard to find however. You might even find

someone >on the

internet.

Paul Lamar




Mark Steitle wrote:


What is the proper seal/slot clearance?




0.002 to 0.0039 inches. Maximum allowable is 0.0059 inches.
1994 Workshop Manual.

Paul Lamar


Barnhart wrote:


Mark,

You and I are on the same road with the 20b.  Here is my take.  I know that
the rotors will have to be modified to fit the 3mm racing seals.  While the
seals are being modified, the rotors will also be balanced. I also remember
part of the selling point of these seals were the springs.  Are the springs
set up for a certain rpm range?

Barny


 
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