Originally Posted By: fdcg27
Originally Posted By: ZeeOSix
Originally Posted By: Shannow
Felix Wankel's major efforts were in the field of sealing systems, which were forced upon him by his novel engine design which had huge lengths of sealing area for a given unit of swept volume.
Mazda perfected the Wankel. They had a few issues in the early days with rotor seals in the RX-2, RX-3, RX-4 ... but by the time the RX-7 came out in 1978 they had it all solved.
They did?
The proportion of RX-7 and RX-8 cars that got warranty engines doesn't gibe with this.
There were good reasons that manufacturers with far greater engineering resources than Mazda, like GM and DB played with this engine back in the seventies and ultimately walked away from it.
Where there warranty issues due to rotor seals, or something else. I've seen 1978 RX-7s with 200K miles on the engine without any problems. The RX-2, 4 & 4 blew rotor seals and burned lots of oil as a result ... RX-7s didn't blow rotor seals (usually tip seals) unless they were boosted pushing huge amounts of boost pressure and weren't tuned right for massive boost.
I owned two RX-7s (1988 & 1995 twin-turbo) and drove them hard ... they never had any engine problems.
Lots of talk in the link below about rotor seal issues on the early engines, and how Mazda was always changing rotor seal design as they developed the Wankel throughout the years. Mazda was smart enough to figure it out ... GM and others weren't.
https://en.wikipedia.org/wiki/Mazda_Wankel_engine