Paul:  Several months ago I read on your list that
someone (you?) had warned that using anything other
than stock Mazda apex seals was asking for trouble,
due to wear problems on rotor housings and that
product names would be named...

Did I miss the naming part?

Kevin Richey


No you did not. Nobody other than Mazda is making acceptable
ferrous apex seals.

Apex seals are not easy to make.
They require special alloys and manufacture technique
such as lasers and liquid nitrogen.
NOBODY has or is using  this technology other than Mazda.
If you buy after market seals you are risking your life
to save a few bucks. Don't take my word for it.  Ask the guys
that have 30 or 40 years experience each rebuilding and racing
rotaries like Dave Lemon at Mazdatrix and Jim Mederer at Racing Beat.

Here again is the history of the apex seal.

http://www.rotaryeng.net/history.txt

"People still ask me this question; "What about the apex seals? I have heard
that Wankel engines have trouble with the apex seals." That problem went
away in about 1965. However that is not to say that the apex seals have not
continuously been improved to this day. The apex seals are central to the
power generated and the efficiency of the Wankel rotary engine. The latest
apex seals are very sophisticated and beyond the manufacturing capability of
just about anybody but Mazda. Many people and companies have tried in the
past to manufacture apex seals. Some seemed to work fairly well but the life
of the apex seal was suspect. Some caused chatter marks as the exact alloy
or surface finish was incompatible with the rotor housing wear surfaces.
Some provided less combustion chamber pressure which translated into less HP
and higher fuel burn due to slight distortion of the warm rotor housing not
matching the distorted shape of the hot apex seal. To make a better apex
seal is harder than it looks. There is only one person that sells better
apex seals than those you can buy from Mazda. Francisco Iannetti
manufactures expensive ($200 each) silicon nitride apex seals that have, for
all practical purposes, unlimited life and excellent performance."

Merry Christmas and a happy new year.

Paul Lamar ...No rotor no motor.

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