The original 1964 Porsche 911 had a 2.0-liter engine. Its air-cooled, rear-mounted flat-six displaced about 1,991 cc, conventionally rounded to 2.0 liters.
The car began production in September 1964 after Porsche displayed a prototype in 1963. It was initially known internally as the Type 901, but a naming conflict led Porsche to call the production car the 911. The new model replaced the 356 while retaining Porsche’s rear-engine layout.
The early engine was a horizontally opposed six-cylinder with an overhead-cam design and aluminum construction. Its compact dimensions and low center of gravity helped define the 911’s handling character. Later versions grew to 2.2, 2.4, and 2.7 liters, which can cause confusion when people remember the displacement of a later classic 911 rather than the launch model.