Tuesday 12th April 1977

General Motors (GM) announced it had dropped plans to produce a Wankel rotary engine. The rotary engine is an old engineering principle originally pioneered by Elwood Haynes in 1893. Felix Wankel is credited with inventing the modern design in 1955. The Wankel rotary engine dispenses with separate pistons, cylinders, valves, and crankshafts, and its construction allows it to apply power directly to the transmission. The miracle of the rotary design is that a rotary engine can produce the same power as a conventional engine of twice its size composed of four times as many parts. There is a tradeoff, however. The Wankel rotary engine burns up to twice as much gasoline as a conventional engine, making it, among other things, a heavy polluter. Proponents of the engine argue that its smaller size would allow carmakers to install anti-pollution devices where they wouldn’t fit in a car carrying an ordinary engine. The basic unit of the rotary engine is a large combustion chamber in the form of a “pinched oval” or epitrochoid. Within the chamber all four engine functions take place in the three pockets formed by the rotor and the walls of the combustion chamber. In the same way that the addition of cylinders increases power in a conventional engine, the addition of pockets increases power in a rotary engine. GM, after having considered the production of a rotary engine for a decade, finally decided against the innovation on the grounds that its poor fuel economy would be prohibitive to sales.