This see-through rotary engine reveals exactly how the alternative to cylinders sparks combustion.<br /><br />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.<br /><br />popular rolls royce and mazda car engines use this rotary type of engines
