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 ...

Last month's "How It Works" story gave you the basics of the four-stroke cycle, describing the motion of the intake and exhaust valves in relation to the piston moving up and down in the cylinder.

Many of you have seen the process of making this rotary valve engine with different intake and exhaust system and how I tried to start it. After so many attempts to start this engine, I was ready to ...