BMW 247 engine

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1994 BMW R100RT with type 247 engine
1973½ BMW R75/5 with type 247 engine

The BMW 247 engine is an Air-cooled Flat twin motorcycle engine with two valves per cylinder, also known as the "airhead" boxer. It was used by BMW in its motorcycles from 1969 to 1995.

The /5 variant was introduced in 1969, /6 in 1974 and the /7 in 1977. Before 1981 the ignition was Ignition system. From 1981 it used Ignition system, a lighter Flywheel and was slower.

A number of different models were on the market:

  • CS: the Classic Sport, with a 1000 cc engine.
  • GS: Gelände/Strasse - winner of a number of the Dakar Rally.
  • RS: Renn (Racing) Sport
  • RT: Road Touring
  • S: with the most famous BMW R 90 S, which was as fast as the Porsche Boxster in acceleration.
  • ST: An 800 cc road-styled G/S.

Prior to the type 247, BMW also built other air-cooled flat twin engines known as the Typ 248/1 used for the R45, the R65 and the R65LS BMW motorcycles. Before that they built Flathead engine and Overhead valve engines commencing with the R32 of 1923. After the type 247, BMW substanitally changed the engine design to include partial Oil cooling and four valves per cylinder, a design which was to become known as the "oilhead".

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