Paul Carey wrote:

Gentlemen

Has anybody given consideration to apex seals with this exploration
into PP?
I just spent a few hours with my engine guy (who has a PP 13B in his
RX-7)
comparing 3 or 4 types of housings with PP's. The predominant apex
seal used
with PP's is carbon one piece - due to the lightness and integrity at
speed
over the port. Apparently steel seals can "pop out" across the port
and
cause severe damage to the engine.

A local racer and rotary guru here in Perth - Terry Stacy actually
does a
"bridge PP" to enable the use of steel seals. Basically it is a PP
with a
narrow partition left in the middle to support the middle of the
seal. The
hole is more square to get the same area as a circle.

I am in two minds here. Terry tells me the bridge was designed back
when
apex seals were not that good, but he says the new aftermarket seals
are
much stronger, and aleviates the need for the bridge. Anybody care to
comment?

Regards Paul

Some after market seals have the 45 degree joint about 3/4 of the way
along
the seal. This was started by Hurley Engineering years ago. I suspect
they would not be as good as a one piece seal for P-ports.

Paul Lamar

As long as the p port is not wider than the exhaust port this is a non
issue, I think.     Jerry

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