Crankshaft Bearings
All MINI COOPER engines use five main bearings. Lubrication is supplied through holes in the upper shell directly from the main oil gallery. The upper shell is grooved to transport oil to the lower plain shells located in the bearing ladder.
A thrust washer built into the center upper main bearing shell controls crankshaft end float. The connecting rod and main bearing shells are made of an aluminum base that is rolled onto a low carbon steel backing.