How the Wankel Rotary Engine Works

A 1957 invention by Felix Wankel that replaces heavy, moving pistons with a triangular rotor spinning inside a chamber to create power.

What it covers

The Wankel engine uses a triangular rotor that spins inside an oval-shaped housing. As the rotor turns, it creates three separate combustion chambers that expand and contract. This design allows the engine to perform the four stages of combustion—intake, compression, power, and exhaust—in a continuous, circular motion rather than the up-and-down movement of traditional engines.

What it doesn't cover

• —Does not cover traditional reciprocating piston engines found in most cars.
• —Does not cover electric motors or battery-powered propulsion systems.
• —Does not cover gas turbine engines or jet propulsion technology.

The clever bit

By using a trochoidal (curved) housing, the engine turns linear combustion pressure directly into rotational motion, eliminating the need for a complex crankshaft and connecting rods.

Why it matters

This engine promised a high power-to-weight ratio and extreme smoothness because it lacked the vibration caused by heavy pistons changing direction. It became a symbol of automotive engineering ambition, most notably powering iconic sports cars like the Mazda RX-7 and RX-8.

Real-world examples

• 1.Mazda RX-7
• 2.Mazda RX-8
• 3.NSU Ro 80
• 4.Citroen GS Birotor
• 5.Modern range-extender generators for electric vehicles