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They advertise them on Ebay for a buy-it-now price
of $1200.00. Paul Conner
----- Original Message -----
Sent: Wednesday, April 13, 2005 5:14
PM
Subject: [FlyRotary] Re: Cost of Ceramic
Seals Was Re: Rx-8 Rotors in Rx-7 Block
Ed,
I must say, from what Lynn and others say, these
ceramic seals last forever, especially under our conditions.
I guess it boils down to what you can afford,
they would certainly cause less wear on the housing as
well.
I will have to look at that down the
track!
George ( down under)
Sorry, George, I was mistaken, the seals are
only $300 each or $1800 for a set - only 1/2 the price I first mentioned
{:>)
Ed
Quote from Mazdatrix on Ceramic
seals
Note!!: These cost about $300 EACH ! -- that
means about $1800 (yes!) for 6 seals to do a 2-rotor
engine.
----- Original Message -----
Sent: Wednesday, April 13, 2005 2:38
AM
Subject: [FlyRotary] Re: Rx-8 Rotors
in Rx-7 Block
It would seem to me that they are saying they
run the rotors backwards - that would put the recess in the rotor face
backwards.
The deeper side is to the side of rotation
I'm sure that would cause some power loss - then again I'm not the
expert!
The ceramic apex seals are the seals of
choice, I didn't know they were that expensive!
George (down under)
Appended below is an e mail from the owner
of MazdaTrix about using the Rx-8 rotor in an RX-7 block.
Interesting reading, now if only the ceramic seals were not $3600 for a
set for two rotors I'd be ready {:>). Makes for interesting
reading.
Here is an e-mail that Dave Lemon from Mazdatrix sent an RX-7 forum
member on the subject. Just thought you guys would find it
interesting:
We are using RX-8 rotors in one of our SCCA
E/Production "street port" 86-91 13B non-turbo engines.
We do no
mods to the rotors (except installing the racing rotor bearing).
We
are using RX-8 racing ceramic apex seals (the OEM RX-8 steel seals
warped too much having to cross the exhaust port).
(There IS enough
metal to cut the apex seal groove for either 86-91 2mm seals or earlier
3mm seals -- we are looking into making that service available, but are
not ready yet)
The rotors are run "backwards" (front in rear, rear in
front) so the angle cut on the side of the rotor gives more intake
opening timing (RX-8 uses the cuts for the side exhaust ports).
Do
not use the "oil scraper ring" outside the second oil control
ring.
DO NOT use RX-8 corner seals -- they DESTROY 86-91 side
housings !!!! (use 86-91 corner seals, TRUST ME).
They ARE lighter than 89-91 non-turbo rotors, have
higher compression, and are less expensive.
With
all of the above said: We have YET to attain even the SAME horsepower on
the dyno as we are getting from our race engine(s) using the 89-91
non-turbo rotors !!!
Potentials:
With the RX-8 rotor having
the side seal further outboard, we were able to increase the (ported)
intake opening timing versus the earlier rotors -- it may be too much
??? (does not seem likely)
Running the rotors with the angle cut
for intake opening may also be in the above category.
We always
set pre-92 side seal clearance at about .0015 (1 1/2 thou). The SMALLEST
clearance we could get, using the LONGEST of the available "pre-sized"
RX-8 side seals was about .010 (10 thou), with the worst on this set of
rotors of about .016 (16 thou). This gives a much lower "sealing" than
we like.
Other than the above, at this time we are not at all
sure why the power is less than when using the earlier
rotors.
No, we have not done the REAL test -- run the SAME engine
on the dyno, and only swap the rotors (backwards, then normal). That
equals three builds, and three full dyno on-and-offs + dyno sessions.
Dave Lemon,
Owner of Mazdatrix,
The dyno operator
and driver of the E/P car
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