Pistons

Pistons

The pistons in the new 911 Carrera are forged. Mixture formation and the direct fuel injection (DFI) combustion process require a new piston crown shape. The piston crown is a relatively large part of the combustion chamber and has a major influence on efficient combustion. Its shape also affects mixture preparation and fresh fuel-air mixture stabilization in the spark plug area during injection processes in the compression phase in particular.

NOTE: Piston is not shown in installation position







Piston cooling







The piston crown temperature in the 911 Carrera engines is reduced by means of piston injection cooling. The spray nozzles are forced-fitted into the crankcase and cannot be replaced. To ensure the necessary engine oil pressure at low rpm and high engine oil temperatures, these spray nozzles only open at a higher oil pressure.