Flat-twelve engine

The first known flat-twelve engine was built by Porsche in 1947 for the abandoned Cisitalia Grand Prix racing car.

[1] One engine was built and the car conducted top speed testing, but it never competed in any races.

[3] The 512 F1 was powered by a 1.5 L (92 cu in) flat-twelve engine and raced alongside the V8-engined Ferrari 158 upon which it was based.

[4][5] The success of the Ferrari 312T led other Formula One teams to build flat-twelve engines, such as the 1979 Alfa Romeo 177.

In 1969, the Porsche 917 sports prototype racing car introduced an air-cooled flat-twelve engine.