Rotary Club
The rotary engine natively in the Mazda RX-8 is called the Renesis. It's a kind of hybrid word. The R and E refer to rotary engine (duh), while the rest alludes to the word "genesis". But it's not so much a genesis as a resurrection.
Previous rotary engines (or Wankels, after the original designer Felix Wankel, a German engineer) were never known for their meager thirst or low emissions. The Renesis brought the design up to date, making it able to meet the more stringent emissions demands now in place.
Like the 13B-REW of the FD3S RX-7 before it (and the FC3S RX-7 even earlier), it has two rotors, with each combustion chamber displacing 654cc. But unlike its predecessor, the Renesis reaches a peak output of 250 hp at a screaming 8,500 rpm and maximum torque of 159 lb-ft at a similarly lofty 5,500 rpm-with no forced induction.
Where the 13B-MSP Renesis gains its real advantage is in the port configuration (MSP stands for multi side port). In older 13Bs, exhaust ports used to line up peripherally with the rotor. The new layout has them off to the side, eliminating the carrying over of any spent gases into the next combustion cycle. There's even an added bonus now of having increased intake and exhaust port area compared to previous engines. The result is more stable combustion, better efficiency, lower emissions, and greater power (a 49-percent improvement over its immediate predecessor).
Incidentally, much of the Renesis is assembled by hand. A possible second generation of Renesis (called the 16X), powered by hydrogen, was in Mazda's Taiki concept car. With a bit of luck, the rotary engine may not die when the RX-8 ceases production, which is slated after the 2011 model year.