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

ACL Race connecting rod bearings for BMW M20, M50, M52 and M54 6-cylinder inline engines with standard crankshaft and extra oil clearance. 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 in a standard engine rebuild.

ACL Race Series connecting rod bearings are manufactured from high-strength F781 tri-metal material and are designed to withstand high loads, high engine speeds and increased cylinder pressures. The bearings feature a hardened steel backing, optimised bearing design, improved heat transfer and precise tolerances that help maintain a stable oil film under demanding conditions.

The HX version provides approximately 0.001” / 0.025 millimetres additional oil clearance compared with the standard H version and is typically used when the engine builder requires increased oil clearance for higher loads, higher engine speeds or specific combinations of oil viscosity and operating temperature. Correct oil clearance, accurate measurement of the crankshaft and connecting rods, and precise assembly are essential for optimum service life and reliability.

Specifications:
Type: ACL Race connecting rod bearings HX
Material: Tri-metal copper/lead alloy (F781) with steel backing and overlay
Crankshaft: Standard size (STD)
Connecting rod: For original connecting rods
Oil clearance: Increased oil clearance, 0.055–0.103 millimetres
Bearing design: Identical upper and lower bearing halves
Contents: 12 bearing halves (6 complete connecting rod bearings)
ACL part number: 6B1490HX-STD

Maximum overall length: 18.00 millimetres
Maximum shaft size: 44.991 millimetres
Maximum housing bore size: 48.016 millimetres
Maximum vertical oil clearance: 0.103 millimetres
Maximum wall at crown: 1.477 millimetres
Minimum shaft size: 44.975 millimetres
Minimum housing bore size: 48.000 millimetres
Minimum vertical oil clearance: 0.055 millimetres

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