Paul, This might have been mentioned too, but here goes. 
How about a full wear plate with water holes but no o-ring grooves. A
machined or cast end plate with water sealed sides, but the typical 
outer holes. That is made like an all AL end plate just a
little thinner. Place the wear plate as a part of the standard 
sandwhich. The end plate HAS o-ring grooves  to place a extra set
of o-rings.  The layout is just a little more complicated but 
has lighter weight, AND a hard wear plate.
Excuse me if I'm re-inventing someones wheel here but it should work fine.
Bill Jepson

Yes this was the original idea but the new smaller plate is much 
much easier to seal everywhere. Don't forget the water is still 
passing through many holes in the thin wear plates. Potentially
a source of leaks. If you do a 3D this will become apparent.

In the new design the same O-ring that seals the water
jacket now also seals the plate. No additional seals required.
Also it is much cheaper to make as it is just a simple oval 
with a large hole in the center.

Here is your sketch and some of the originals showing some of 
the required seals.

Paul Lamar
 
The AirCraft Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2003 All world wide rights reserved.