Rotary engine to make a comeback?

[Barry]

Mazda are talking about bringing back the Wankel (That word still makes me giggle) engine in the new RX-9. Twin turbo with 450 BHP suggested. I wonder if this engine will also need rebuilt every few thousand miles?

http://www.mazda-motors.com/news/mazda-hints-at-rx-9-with-450hp-rotary-engine/

[treks]

Unless Mazda can get the apex seals sorted, this new version won't last any longer than the first rotaries did- which is sad, since rotary engines have a lot going for them.

[milane]

Rotary in engines too, all I know about rotary is in AC compressor as smaller AC comes with rotary compressor that is amazingly awesome on electric bills, but fails in super extreme heat of 50+. Is this also have the same story?

[Barry]

@milane As Treks said, the problem with these engines is the apex seals. They wear out pretty quickly causing the engine to lose compression then it won't start when it's warm. Most of these engines need rebuilt at around 60k miles but some need a rebuild as low as 30k. They like to use a lot of oil too. Although in saying that they're bad, they're fantastic when they're working. And the RX-7 was one of the coolest cars ever built, way ahead of it's time when it was first released. The graphic below shows more or less how one of these engines work,