Subject: RX-8 Sensor..
From: Rotary Engine
Date: 12/18/2007, 10:55 AM
To: AARotary Engine



       To All Rotorheads,
           I just want to post a progress report and ask one question;
   first,
       the progress report. Everything is progressing,
       it just doesn't happen fast enough. Modifying an automotive
   engine for
       aircraft use is extremely time consuming. I
       have been at this since June '07, almost six month's and I'm
   still not
       finished (10-14 hour day's, just about seven
       day's per week).
           The engine does look good though; the cast-iron part's are
   painted,
       the aluminum part's are polished (satin finish),
       and even the PSRU has been lightened and polished. I also did some
       really light intake porting. I have my motor-
       mount's ready for welding, the coil's are mounted, and I'm presently
       working on the mounting bracket for an RX-8
       sensor. The bracket was not difficult to design or fabricate and
   for me
       the weight saving's was worth it. Only two
       pound's, but a little here and a little there and before you
   know it you
       have lost ten pound's.My ECU is back from
       Tracy and has been up-dated as well as re-programed for the RX-8
   sensor
       and coil's. Next, the intake and exhaust
       system's and it should be ready to run; hopefully by the end of
   February
       '08.
           Now the question: does anyone know the exact radial off the
   e-shaft
       that the RX-8 sensor sit's. It can be in
       degree's, minute's, second's or in hour's, minute's, second's. I
   can
       work with either one. Starting point, of course,
       would be at the top ("0" degree's or 12 O'clock). Hopefully, one
   of you
       can provide this information. Thank's!

       Frank R. Clementi

       I assume you are installing the RX8 sensor on the 13B Frank.

       There is nothing in the RX8 manual about the position of this
       sensor. Mazda assumes you are using an RX8 E-shaft, computer and
   pulley
       hub. As I recall Mark Steitle installed one on his 3 rotor.

       It looks like it was bolted to a stock 3 rotor hub using the stock
       hole position, spacers and a stock RX8 trigger wheel.

       As I recall Mark's original custom pick up bracket was steel and
       apparently
       the pick up did not like steel. Or perhaps it was the other way
   around.

       What say you Mark?

       Here is an old message.

       01/23/2004 08:33 PM
       Bulent Aliev wrote:
        > >
        > > Hi Paul,
        > > The main pulley diameter on the Cosmo is 128mm about 5". The
       trigger wheel
        > > should be about 135mm I guess?
        > > I just mailed you the RX-8 one Priority USPS.
        > > --
        > >
        > > Bulent

       I got the RX8 trigger wheel Bulent. Thanks. The good news is it fits
       the 2nd gen E-shaft flange weird bolt pattern. I am not yet sure
       about the
       timing but Tracy could handle that in software.

       Paul Lamar


   Frank,
   I took reference for the location of the CAS from a Renesis engine.  The
   easy way would be to adapt a Renesis front cover.  You could save an
   extra pound or two with the Renesis water pump (assuming you have a cast
   iron water pump).  If you get it close, you can adjust the timing with
   the EC-2.

   In order to get the timing wheel, I had to buy an entire Renesis front
   hub.  You might be able to find just the timing wheel used.  The Renesis
   hub won't fit on the old engines and the bolt holes don't match the RX-7
   hub, so you'll have to re-drilled the timing wheel holes.  That should
   be done in a lathe.  As I recall, there is a diamond-shaped mark on the
   timing wheel that points to 12 o'clock when at TDC, but check &
   verify this before drilling.

   Keep in mind that the gap between the CAS sensor and the timing
   wheel needs to be about .020".  Wider than that and the signal
   gets scrambled and the engine mis-fires at higher rpm.  Also, make sure
   the sensor is centered on the timing wheel and don't make the bracket
   out of ferrous material as this will also cause the signal to
   get corrupted.

   My recommendation would be to either adapt the Renesis front cover to
   your engine or use the original CAS.

   Mark S.


   "bolt holes don't match the RX-7  hub"

   Mark, do you know if this holds true for the 3rd gen engine?
   I think Bulents Cosmo engine had the same hub as the 3rd gen
   engine. Your  20B three rotor hub used the 2nd gen style  CAS.

   Paul Lamar


Paul,
You're correct that the 3rd gen engine uses the Renesis style sensors.
But I think it used two.  Also, the water pump runs off the back side of
the serpentine belt.  I don't know what else is different.

Mark S.



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