Engine Components: Crankshaft: Notes

The crankshaft of the N55 is of lightweight design, at 20.3 kg it's approximately 3 kg lighter than the crankshaft in the N54 engine.

The crankshaft is made from cast iron (GGG70). The counterweights are arranged asymmetrically. There is no incremental wheel installed on the crankshaft. The timing chains are mounted by means of an M18 central bolt.

Fig 1: Identifying N55 Crankshaft

Courtesy of BMW OF NORTH AMERICA, INC.