Porsche 547 engine

The Porsche 547 engine, often called Fuhrmann engine after Ernst Fuhrmann, was introduced in 1954 by Porsche to upgrade the mid-rear-engine Porsche 550 sportscar. Still based on the Volkswagen design, thus an air-cooled naturally-aspirated flat-four boxer engine, it was intended for racing and fitted with no less than four camshafts (DOHC).

Fitted with the new engine that initially developed 110 hp from 1500cc, the Porsche 550 soon received a new frame and was called 550A. The 4-cam engine was also used in the successor Porsche 718 that was even turned into Formula 2 and 1 cars. After the 1962 Formula One season, Porsche left F1 to re-focus on road-going sportscars, offering the Porsche 904 Carrera GTS with the final edition of the Fuhrmann engine, some 180 hp from 2000cc.

By the time, there were also the flat-8 Type 771 Porsche flat-eight engines and the new Porsche flat-six engine Type 901 as introduced in the Porsche 911 (classic). The F6 design was chosen for the 1966 series of Porsche 906 Carrera 6, making the F4 obsolete.