BMW 801

The engine cylinders were in two rows of seven cylinders each, the bore and stroke were both 156 mm and a capacity of 41.8 litres. The engine generated between 1,600 and 2,000 h.p. The unit (including mounts) weighed around 1,250 kg and was about 1.27 m across, depending on model.

The engine was developed from experienced gained when BMW had been manufacturing similar Pratt and Whitney engines under license in the 1930s. It is distinctly different from the American engines and incorporated MW50 fuel injection, initially methanol-water. Later engines also had a gear-driven two stage supercharger. The boost could, in emergency, push the engine output from 1,600 h.p. to around 2,100 h.p.

Radial engines were uncommon in successful European fighter aircraft until the BMW 801 was used in the Focke-Wulf Fw 190, with armoured oil tank and powerful cooler gear in the cowled nose section and multi-stack ejector exhaust. Initially the engines had a tendency to overheat and also produced unpleasantly high temperatures in the cockpit. This problem was soon solved but later Fw 190s, the 1943 'D' and after, tended to use the Junkers Jumo 213, or in the 'Ta' designs of Kurt Tank liquid-cooled Daimler-Benz DB 603 variants.

An additional feature on the BMW engine in the Fw 190 was the Kommandogeraet, a hydraulic-electric unit that automatically adjusted engine fuel flow, mixture and timing with propellor pitch in response to throttle demand and also engaged the supercharger.

• 801A 1,600 h.p.
• 801D 1,730 h.p.
• 801S or TS 2,000 h.p.
• 801F 2,400 h.p., development halted by the end of the war