Aflat-sixteen engine, also known as ahorizontally opposed-sixteen, is a sixteen-cylinderpiston engine with eight cylinders on each side of a centralcrankshaft.
Flat-sixteen engines are less common thanV16 engines, with only a couple of prototype racing engines using a flat-sixteen layout.
These engines had twoconnecting rods percrankpin, so they could also be referred to as a 180 degree V16, rather than aboxer configuration as used by most flat engines with six cylinders or less.[1][2]
TheCoventry Climax FWMW was a prototype flat-sixteen engine designed between 1963 and 1965 that was intended for use in Formula One.[3] TheBrabham andLotus teams designed cars for this engine but it was never raced. This was due to reliability problems in testing and a failure to generate the desired power output.[4][5][3][6]
In 1971, Porsche developed a flat-sixteen prototype engine to use in thePorsche 917 that competed in the Can-Am championship.[7] The project was abandoned and the 1972 Porsche 917/10K was instead powered by a turbocharged version of Porsche's existing flat-twelve engine.[8]