TYPE 911

We return to our detailed history of Porsche’s flat-six engine in 1970, when the designation officially changed from ‘901’ to ‘911’. Just seven years after Porsche first showed its flat-six engine and the 911 to the world, its development took a sharp upwards trajectory.

It signified the start of a period of serious development for the boxer unit. As we covered in the first article, covering the conception of the flat-six, the engine was designed from the start to allow for significant bore increases without changing the cylinder spacing – a bore enlargement from 80- to 100 millimetres was foreseen. The first increase in capacity took place for the 1970 model year, when the bore was increased from 80- to 84mm. With an unchanged stroke (of 66mm), the resulting swept capacity was upped from 1991 cubic centimetres to 2195cc.

Porsche initially retained the 911’s range structure, though all models got the new 2.2-litre engine with higher power outputs. The 911 T went from 109- to 123bhp; the 911 E gained 15bhp to make 153bhp; and the range-topping