Big end bearings - engine set

These bearings are suitable for use in all Rolls-Royce and Bentley engines having a crankshaft with a nominal diameter of 2.250". They are supplied undersize on the internal diameter, and once fitted correctly to the connecting rods they have to be machined to suit the diameter of the crankshaft.

The bearings originally fitted by Rolls-Royce to the 20/25 engine had an oil transfer groove machined on the back of the upper shell. The reduction in thickness in the steel backing as a result of the groove allowed slight flexing in the steel under load which caused cracking in the white metal. Consequently a modification was introduced. This deleted the groove on the shell, and replaced it with a similar groove machined on the inner surface of the connecting rod which lined up with the oil holes in the shell.

The bearings that we supply are manufactured without the oil transfer groove. If fitted to connecting rods that have not been grooved the connecting rods will have to be modified.