ACL - BMW M20/M50/M52/M54/S50/S54 Main Bearing Set (7M1532H)

ACL Race Series performance engine bearings are manufactured
to exacting tolerances. Micron tolerance machining supported by precision measurement systems delivers consistent accuracy to key characteristics like wall thickness and crush. This ensures reliable fit and helps maintain consistent clearances. 

ACL Race Series performance engine bearings sets are identified by the ‘H’ after the set number e.g. 8B663H-STD.

Most ACL RACE Series performance engine bearings are also produced in a ’HX’ version e.g. 8B663HX-STD. The ‘X’ signifies the set will give an extra .001” (0.025mm) oil clearance on a standard size shaft when compared to the H-STD set. The wall size of these HX-STD bearings is .0005” (0.013mm) thinner than the H-STD bearings, in all other respects the HX set is identical to the H-STD set.

There are selected con rod bearing sets that are manufactured with a dowel hole in the lower shell to suit a dowel location in the con rod cap. These are designated with a ‘D’ in the set numbering e.g. 8B663HD-STD or 8B663HXD-STD etc.