Lynn—
I have a 13B NA which has previously been converted to propane by Rotary
International Enterprises (?) and has to be reconverted to mogas/avgas.
It allegedly has 17 hours of runtime on it and also was claimed to have
been rebuilt using “ceramic seals”. When we do a tear down on it for
inspection, at the risk of sounding totally naïve, how do we ascertain that it
truly does have ceramic seals on it and would you recommend that we
simply just go ahead and replace them with more traditional seals
regardless? (Comments from not only you but also anyone else would be
greatly appreciated.)
Paul
Vermillion
(partially
completed BD-4)
From: Rotary motors in
aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Lynn
Hanover
Sent: Sunday, June 08, 2008 12:46 AM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Ceramic apex
seals
There
are one piece carbon / aluminum seals, not too expensive, great for racing.
Good sealing
never
hurt the rotor housings. Can handle some boost. Very light and can do monster
revs over 10,000 RPM. You have to be a memebr of the Mazda competition program
and provide pictures of your race car and finish sheets from a number of
events.
The
very best are ceramic one piece seals. Scary light. Strong enough for high
boost. Not affected by engine over temps or detonation. Run with two springs
for tracking at scalding high revs and still have less drag than stock or
carbon seals. No downside until you try to buy them.
About
$330.00 each seal, (you need 6). This is a bolt on 6 HP just from reduced
drag. No rotor housing wear. From Mazda comp. and after market vendors. Carbon
as well.
Newbie
Question---for the "normal"13B NA engine, how do the ceramic apex seals
compare with the other types of seals you all are using? (I've rarely
ever read anything about their use in this
forum.)
Paul
Vermillion