Rotary engines (also known as Wankel engines and Wankel rotary engines) are quite different from piston or "reciprocating" engines. One of the distinguishing features is that they don't need valves to ...

Rotary engines differ from conventional ones in many respects — and one of them is the fact that they use two different spark plugs. Here's why.

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.

Mazda 13B rotary engine in a white Mazda RX-7 engine bay. - TTTNIS/Wikimedia Commons When it comes to unconventional engine design, few exceed the Wankel rotary in terms of weirdness. Despite that, ...