Crankcase

Crankcase

The crankcase in the Porsche Cayenne S and Cayenne Turbo is designed as a two-piece closed-deck component in a light metal alloy (AlSi17Cu4Mg). In the closed-deck design, the sealing surface of the crankcase is, for the most part, closed to the cylinder head - only the bores and channels for oil and coolant are available. The entire structure is additionally strengthened as a result of this design. This leads to less cylinder distortions and helps to reduce oil consumption.







The alloy used for the crankcase is known as a hypereutectic alloy in which silicon crystals form. These silicon crystals are exposed using several specialised honing processes in order to make the surface more durable.







To further improve pedestrian safety, the crankcase has been lowered by -> length: 20 mm compared to the previous engine. As a result, the coolant pump and thermostat housing cover are also 20 mm lower and a modified water flow system was needed.

The lower part of the crankcase is machined and paired together with the upper part.
To keep the weight as low as possible, the spheroidal graphite iron inserts are no longer used and the wall thickness has been reduced.







A low-pressure chill-casting procedure is used to make the upper and lower part of the crankcase.