Engine – Cayenne V8
Page 1.18
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 exposed. 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 specialized honing processes in order to make the surface more
durable. The crankcase has been lowered by 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 circuit was
required.
20 mm
V8 - 4.8 (2nd Generation) V8 - 4.5
Modified water flow circuit.