So, How Does It Work? The Wankel Rotary Combustion Engine Theory, Design, and Principles of Operation Internal combustion engine: fuel air mixture ignites and the explosion directly drives the engine internally. Four phase Otto Cycle engine: intake, compression, power, exhaust. Three main moving parts in most RC engines: 2 rotors and the eccentric shaft. These rotate continuously in a single direction. They do not jerk backwards and forwards. These are surrounded by the peripheral housing where the rotor tip traces out an epitroichoid curv ....