ACL conrod bearings BMW M20/M50/M52/M54 STD

ACL Race connecting rod bearings for BMW M20, M50, M52 and M54 6-cylinder inline engines with standard crankshaft. ACL Race Series is developed for high-load engines and is often used for tuning, motorsport and performance rebuilds where higher demands are placed on the bearings than during a standard engine rebuild.

ACL Race Series connecting rod bearings are manufactured from high-strength F781 trimetal material and developed to handle high loads, high RPM and increased cylinder pressure. The bearings feature hardened steel backing, optimised bearing design, improved heat transfer and precise tolerances, helping to maintain a stable oil film under demanding conditions.

Improvements in material, dynamic wall thickness, heat transfer and bearing design are some of the features that have made ACL Race Series a popular choice among engine builders worldwide. Correct oil clearance and precise installation are essential for optimal service life and reliability.

Specifications:
Type: ACL Race connecting rod bearings
Material: Trimetal copper/lead alloy (F781) with steel backing and overlay
Crankshaft: Standard size (STD)
Connecting rod: Original connecting rod
Oil clearance: 0.029–0.077 millimetres
Bearing type: Upper and lower connecting rod bearings
Contents: 12 bearing halves (6 complete connecting rod bearings)
ACL part number: 6B1490H-STD

Maximum total length: 18.00 millimetres
Maximum shaft size: 44.991 millimetres
Maximum housing bore size: 48.016 millimetres
Maximum vertical oil clearance: 0.077 millimetres
Maximum wall at crown: 1.49 millimetres
Minimum shaft size: 44.975 millimetres
Minimum housing bore size: 48.000 millimetres
Minimum vertical oil clearance: 0.029 millimetres

Fits engine codes:
M20B20 / M20B23 / M20B25 / M20B27 / M50B20 / M50B20TU / M50B25 / M50B25TU / M52B20 / M52B20TU / M52B25 / M52B25TU / M52B28 / M52B28TU / M54B22 / M54B25 / M54B30