porsche m97-21

The Porsche flat-six engine series is a line of mechanically similar flat-six boxer engines, produced by Porsche for over 60 consecutive years, since introduced in the 1963 rear-engine Porsche 911, and as mid-rear mounted racing engine in the 1966 Porsche 906 Carrera 6, each with 2000cc.
All Porsche F6 boxer engines, naturally aspirated or turbocharged, remained air-cooled with additional oil cooling until in the late 1970s some turbo-charged endurance racing engines were constructed partly or completely water-cooled to be mainly used in the Porsche 956/962C sportscar racers in the 1980s. Related designs are still in use in the high-performance GT3/GT2 range. The regular 911 models used the air-cooled F6 until the 1990s Porsche 993, and starting with the Porsche 996 are fitted with a simpler and cheaper range of water-cooled engines less suited for racing....