ryanvx

iTrader: (1)

I was down at the mazda dealership in Everett trying to coax some anwsers out of their service rep. about the problems with the renesis engine (mine was being replaced) ... over heating... lack of lubrication... alot of stonewalling... does anybody know what the apex seals in the RX8 engine are made of?
compared to the RX7?

arghx

iTrader: (3)

The underlying problem was the lack of an OMP oil injector for the middle portion of the housing trochoid surface. The previous fuel injected rotaries had an injector in the middle of the housing but the series 1 Renesis did not. That was corrected in the 2009 model year. The OMP was also completely redesigned. Before it used a stepper motor to meter oil (a design that goes all the way back to 1989 series 5 Rx-7). The new design is kind of like a returnless fuel system. It has more precise control over each injector.



He probably didn't "stonewall" you. Most service reps are basically just salesmen. They're not engineers and they're not technicians.



The biggest differences are the dimensions of the seal, and the fact that they are 2 piece (like the pre-'86 seals) instead of the 3 piece seals that came from the factory for '86-2002. The 3 piece design actually seals better so less gases can escape, but anecdotally speaking the 2 piece seals tend to wear better and are less likely to separate and break.

If you have a 2004-2008 model year Rx-8 the only real work-around for the premature wear is to put 2 stroke oil into the gas tank.