Porsche’s venerable M97 flat six engine – the ultimate automotive Grandfather’s Axe – will be shuffled off to the retirement home next year, as the newer, smarter, direct-injected A91 boxer six from the updated 911 Carrera gets shoehorned into the engine bays of Porsche’s hi-po GT3, GT2 and 911 Turbo.

With it comes the benefits of direct fuel injection technology, which promises greater fuel efficiency and less CO2 output while boosting power through the promotion of ideal combustion patterns. The A91 should also transform the behaviour of the new Porsches, as bore and stroke has changed from the M97’s 100mm x 76.4mm to a more ‘square’ 97mm x 81.5mm, which roughly translates into a more rev-happy engine (and a small increase in total displacement).

Engine size will be a familiar 3.6 litres for the turbocharged GT2 and 911 Turbo, while the naturally-aspirated GT3 will likely get a 3.8-litre mill as well as lighter pistons than the force-fed motors. Official numbers have yet to be released, but current estimates say the Turbo will put out 373kW with the new engine, the GT3 around 321kW and the GT2 410kW.

[Autocar