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 ...

Intake, compression, power, then exhaust. Every 4-stroke engine ever made – about 80% of all engines currently in existence – function on this principle – even rotary engines. But now, Porsche has ...