Rotary Engine (see inside while it's working)

This see-through rotary engine reveals exactly how the alternative to cylinders sparks combustion.

The rotary engine was an early type of internal combustion engine, usually designed with an odd number of cylinders per row in a radial configuration, in which the crankshaft remained stationary in operation, with the entire crankcase and its attached cylinders rotating around it as a unit. Its main application was in aviation, although it also saw use before its primary aviation role, in a few early motorcycles and automobiles.

popular rolls royce and mazda car engines use this rotary type of engines