Subject: RX8 Parts

     > George Lendich wrote:
     >
     > Paul,
     > Interesting conversation I recently had with the local engine builder on RX8 Parts and their interchangeability with the RX7.
     >
     > He recently built a RX7 racing engine with RX8 rotors - I thought the RX8 rotors were quite a bit wider ?
     > I also thought the bearing sizes were different - but apparently not !
     > Anyhow all went well until he got to 10,000 RPM when the rotors were binding on the endhousings, so they shaved (just a little) off the sides of
     the rotors.
     >
     > He also noted that the rotor side seals were much shorter( in length) that RX7 side seals. He was concerned about too muck leakage but they worked
     OK he can
     > only put down the extra gap in the side seal ( to the apex side seals) as needed because the side seals were exposed to greater heat of the side
     exhaust and
     > therefore expanded more!  Apparently some people put in bigger apex side seals to make up the difference in gap.
     >
     > Also the apex seals were shorter in height so they cut the slot deeper and put in Hurley apex seals.
     >
     > Speaking of Hurley apparently they have a 2 piece side seals ( very thin) which are very flexible and tough.
     > I suggested using a bi-metal hacksaw blade and grind it down to size as they are very flexible and tough - the new hacksaw blades out now don't
     break at all.
     >
     > Cheap side seal idea if anyone wishes to try it.
     > George (down under)

-> "Powell, Ken" wrote:

George, great info.  I have wondered if you could use the rx8 rotors in an earlier 13b.  The lighter rotors would allow us to turn higher rpm safely.  If you
are using a PP intake port this sounds like a less expensive route than a new rx8 engine.  Looks like you would need rx8 rotors, seals, and front/rear
counterweights to make this work.  Maybe the 86 - 91 counterweightes can be used if the rotating assembly is balanced.  Does anyone know if weight would have
to be added or removed from the counterweights to work with the new rotors (seems like the weight would need to be removed from the counterweights to balance
lighter rotors but sometimes things don't work like it would appear at first)?

Ken Powell- 

Dave Atkins had a 1993 3rd gen and an RX8 rotor at OSH. The appear to be the same weight.
 
The Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2004 All world wide rights reserved.