"Brian D. Cain" wrote:

I've been reading this thread a bit guys and I think I may be able

to

shed

a little more like on the subject.
Hope this helps.  I'd like to open the subject up more on the issues
concerning the after-effects of substantial engine knock and the

differences between

the types of apex seals that are available (in particular 2mm

2-piece

vs. 2mm

3-piece).

George Lendich wrote:

Brian,
Speaking for myself, please give us your opinion on any matter

concerning

the Rotary, I've got a couple of questions already.
George (down under)

-"Brian D. Cain" wrote:

Hey George,

I'm still not totally sold on the idea of 3mm although I did use them for
some time
on an engine that I ran on one of my setups for a few years.  I've been
going back
and forth with it and the only conclusion I can come up with is that they're
used
and/or recommended because they're a bandaid.  That's the only thing I can
truthfully conclude about that.  From some people I've spoken to on it (that
are
decidedly anti-3mm), they've said that there's increased wear on the rotor
housings
near the leading/trailing spark plug holes from chatter, there's less
sealing and more
blow-by at lower RPM's, and there's something else also concerning shearing
and
loads put against the seal but I don't know.  It's an area of science I'm
unfamiliar
with; perhaps some of you more enlightened guys can shed some light on that.

The other issue I've been curious about is the use of 2-piece 2mm vs.
3-piece 2mm
apex seals with respect to their resilience to severe engine knock.
Regardless of
the alloy or heat treatment used on the seal for strength purposes, is it
possible that
a 2-piece seal, where both of the "long" portions of the apex seal are one
piece, is
structurally stronger as opposed to its 3-piece counterpart?  Every engine
that I've
seen personally let go from engine knock has always used the factory, Mazda
3-piece design.  It seems to me that a thicker chunk of anything would
withstand
more impact or force than something that was the same mass yet split into
two pieces.
Anybody have anything they could add to that?

B

Brian D. Cain -/- Grand Prairie, TX -/- bdc196@comcast.net
BDC Motorsports - Performance Rx-7 13B Rebuilds, EFI tuning, etc.
MSN bdc196@hotmail.com, Yahoo! bdc196, AOL Symajhi, ICQ# 1733105
http://bdc.cyberosity.com -/- http://groups.yahoo.com/group/HaltechSupport

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