The internal combustion engine, for all its mechanical sophistication, still runs on a 19th-century mechanical idea: pistons rising and falling, a crankshaft spinning, a steam-age architecture ...

For more than a decade the name Wankel has popped up whenever car enthusiasts start talking about advanced-design automotive powerplants. The theory of the Wankel engine goes back to 1954 when Dr.

Wankel rotary engine powered thousands of aircraft. One of several problems: It spewed castor oil on its pilots.