Paul,
The headers and intake tubes should be welded up in a couple of
weeks, so now I am looking for all of the pieces to rebuild the
engine. Lynn mentioned solid corner seals without rubber plugs.
They tend to last longer.  I looked at Mazdatrix and they have one
for 3mm seals.  Would it be worth the trouble to go to 3mm seals?
They also have a differnt corner seal sprig that looks like a bent
up flat washer.  Any good words or are these parts all hype?

Thanks
Joe Berki
Limo EZ
P Port

I do not know very much about the subject of corner seals.
I do know the RX8 engine uses DLC Diamond Like Coating on the
corner seals. That is about it. I could be forgetting something
that was said years ago.

I would not do the 3 mm unless your apex seal slots are worn.
Do they pass the vertical apex seal wiggle test? If so I would
leave them alone. I ran across a technical letter recently in
my paper files by Dr. Francisco Iannette. I'll OCR it some day
and publish it. According Francisco silicon nitride apex seals
do not wear the slots I was amazed to find out. We are now
getting close to infinite life for the rotary :)

Paul Lamar


Check Hurley Engineering website. Corner seals with 3 springs behind
instead
of the Mazda springs. 2mm and 3mm available.

Dale Davies

The corner seal plugs tend to disappear in high rpm/power engines.
Engines run fine without them, probably less apex damping and slightly
lower compression.
There are several solid corner seals out there - Atkinsrotary, Scoot,
Hurley, stock Mazda 3mm solids.  I heard mazdacomp used to sell some as
well.

Maybe Lynn can tell us which ones he has used.
Search rx7club.com and nopistons.com.  Threads mention improper
machining, clearance, soft metal seals that bent and premature wear.
Note that the OEM Mazda seals are chromed - presumably for decreased
wear.
The RX8 metal corner seal plugs look like a better compromise if you
have RX8 rotors.
You reminded me, I have been meaning to try rx8 apex and corner seals
(with metal plugs) in RX7 rotors.  This would require fixing a shim in
the rx7 apex slot to compensate for the height difference.

The 93+ bent washer style corner seal springs will tolerate higher
temperatures better and are less likely to stick/gum-up at lower power,
but they seem to increase the corner seal wear rate on the housings.

When in doubt stick with OEM - even if the plugs only last so long.

Cheers
Cary

The early solid corner seals are just fine up to 11,000 RPM. The only
failure I have ever had was on of the rubber plug items. All of the OEM
seals are powdered metal. It is fine as a solid piece but does not stand
up to flexing as in the rubber plug idea. The flat springs replaced the
fine wire springs. Never a failure. Much easier to assemble than the
wire spring as they like to be in a drop of grease to prevent movement
during assembly. The flat spring just drops in. No problems.

The rubber plug type seals give slightly better compression until they
get hard. Then turn to dust or break up into chunks and exit across the
side seals. Then you have less compression than the solids, and possible
damage as well. Just no point to it.

Lynn E. Hanover