ACL Race Series Reinforced Rod Bearings - BMW M20, M50, M52, M54 (E30, E34, E36, E38, E39, E46, E60)

Engineering Bulletin

ACL provides an official guide for clearance control and optimization, and guidelines for bearing size selection : download it here.

ACL Race Series Reinforced Rod Bearings

Designed to withstand high RPM, temperatures and load, these ACL Race Series bearings are manufactured from 3 layers of hardened steel, copper and nickel. This "trimetal" composition substantially lowers friction, and thus reduces the operating temperatures while providing superior lubrication.

To help engine builders optimise clearances for their specific applications, ACL provides a range of different bearing sizes for standard crankshaft journal sizes:

• H-STD: Bearing thickness is precision finished to provide a nominal clearance based on OEM specifications. Suitable for all applications using crankshafts finished to OEM specifications.
• HX-STD: Providing an extra .001" (0.025mm) of clearance over the H-STD size bearings. Suitable for high to extreme power applications where additional clearance is beneficial to part reliability.
• H-001 / H-.025: Providing a reduction of .001" (0.025mm) of clearance over the H-STD size bearings. Suitable for adjusting clearance to compensate for surface reconditioning (polishing) of crankshaft journals or the use of low viscosity lubricants.

Please note: there are also HD (with location dowel holes) and HXD (with location dowel holes and 0.025mm (0.001") extra clearance) part numbers, reserved for some connecting rod bearing applications only.

Application List & Engine Codes

• BMW/3 (E36)/320 i/M50B20
• BMW/3 coupe (E36)/320 i/M50B20
• BMW/3 Convertible (E36)/320 i/M50B20
• BMW/5 (E34)/520 i 24V/M50B20
• BMW/5 Touring (E34)/520 i/M50B20
• BMW/320, 520, Z3/DOHC 24v/M50B20
• BMW/323/SOHC 12v/M20B23
• BMW/320, 520, Z3/SOHC 12v/M20B20
• BMW/3 (E30)/325 i/M20B25
• BMW/3 (E30)/325 i X/M20B25
• BMW/3 Convertible (E30)/325 i/M20B25
• BMW/3 Touring (E30)/325 i/M20B25
• BMW/3 Touring (E30)/325 i X/M20B25
• BMW/5 (E34)/525 i/M20B25
• BMW/Z1 Roadster/2.5/M20B25
• BMW/325, 525, Z4/SOHC 12v/M20B25
• BMW/3 (E30)/325 e 2.7/M20B27
• BMW/5 (E28)/525 e/M20B27
• BMW/325/SOHC 12v/M20B27
• BMW/Z3/DOHC 24v/M54B22
• BMW/328, 528, Z3/DOHC 24v/M52B28
• BMW/330, 530, X3, Z3, Z4/DOHC 24v/M54B30
• BMW/3 (E36)/320 i/M52B20
• BMW/3 (E36)/325 i/M50B25
• BMW/3 (E36)/323 i/M52B25
• BMW/3 (E36)/328 i/M52B28
• BMW/3 (E46)/320 i/M52B20
• BMW/3 (E46)/320 i/M54B22
• BMW/3 (E46)/323 i/M52B25
• BMW/3 (E46)/325 xi/M54B25
• BMW/3 (E46)/325 i/M54B25
• BMW/3 (E46)/328 i/M52B28
• BMW/3 (E46)/330 xi/M54B30
• BMW/3 (E46)/330 i/M54B30
• BMW/3 Compact (E36)/323 ti/M52B25
• BMW/3 Compact (E46)/325 ti/M54B25
• BMW/3 coupe (E36)/320 i/M52B20
• BMW/3 coupe (E36)/325 i/M50B25
• BMW/3 coupe (E36)/325 is/M50B25
• BMW/3 coupe (E36)/323 i/M52B25
• BMW/3 coupe (E36)/328 i/M52B28
• BMW/3 coupe (E46)/320 Ci/M52B20
• BMW/3 coupe (E46)/320 Ci/M54B22
• BMW/3 coupe (E46)/323 Ci/M52B25
• BMW/3 coupe (E46)/325 Ci/M54B25
• BMW/3 coupe (E46)/328 Ci/M52B28
• BMW/3 coupe (E46)/330 Ci/M54B30
• BMW/3 coupe (E46)/330 xi/M54B30
• BMW/3 Convertible (E36)/320 i/M52B20
• BMW/3 Convertible (E36)/325 i/M50B25
• BMW/3 Convertible (E36)/323 i/M52B25
• BMW/3 Convertible (E36)/328 i/M52B28
• BMW/3 Convertible (E46)/320 Ci/M54B22
• BMW/3 Convertible (E46)/323 Ci/M52B25
• BMW/3 Convertible (E46)/325 Ci/M54B25
• BMW/3 Convertible (E46)/330 Ci/M54B30
• BMW/3 Touring (E36)/320 i/M52B20
• BMW/3 Touring (E36)/323 i/M52B25
• BMW/3 Touring (E36)/328 i/M52B28
• BMW/3 Touring (E46)/320 i/M52B20
• BMW/3 Touring (E46)/320 i/M54B22
• BMW/3 Touring (E46)/325 xi/M54B25
• BMW/3 Touring (E46)/325 i/M54B25
• BMW/3 Touring (E46)/328 i/M52B28
• BMW/3 Touring (E46)/330 i/M54B30
• BMW/3 Touring (E46)/330 xi/M54B30
• BMW/5 (E34)/525 i 24V/M50B25
• BMW/5 (E34)/525 iX 24V/M50B25
• BMW/5 (E39)/520 i/M52B20
• BMW/5 (E39)/520 i/M54B22
• BMW/5 (E39)/523 i/M52B25
• BMW/5 (E39)/525 i/M54B25
• BMW/5 (E39)/528 i/M52B28
• BMW/5 (E39)/530 i/M54B30
• BMW/5 (E60)/520 i/M54B22
• BMW/5 (E60)/525 i/M54B25
• BMW/5 (E60)/530 i/M54B30
• BMW/5 Touring (E34)/525 i/M50B25
• BMW/5 Touring (E34)/525 ix/M50B25
• BMW/5 Touring (E39)/520 i/M52B20
• BMW/5 Touring (E39)/520 i/M54B22
• BMW/5 Touring (E39)/523 i/M52B25
• BMW/5 Touring (E39)/525 i/M54B25
• BMW/5 Touring (E39)/528 i/M52B28
• BMW/5 Touring (E39)/530 i/M54B30
• BMW/5 Touring (E61)/525 i/M54B25
• BMW/7 (E38)/728 i, iL/M52B28
• BMW/7 (E65, E66, E67)/730 i, Li/M54B30
• BMW/X3 (E83)/2.5 i/M54B25
• BMW/X3 (E83)/3.0 i xDrive/M54B30
• BMW/X5 (E53)/3.0 i/M54B30
• BMW/Z3 coupe (E36)/2.8 i/M52B28
• BMW/Z3 coupe (E36)/3.0 i/M54B30
• BMW/Z3 Roadster (E36)/2.0 i/M52B20
• BMW/Z3 Roadster (E36)/2.2 i/M54B22
• BMW/Z3 Roadster (E36)/2.8 i/M52B28
• BMW/Z3 Roadster (E36)/3.0 i/M54B30
• BMW/Z4 Roadster (E85)/2.2 i/M54B22
• BMW/Z4 Roadster (E85)/2.5 i/M54B25
• BMW/Z4 Roadster (E85)/3.0 i/M54B30
• BMW/325/DOHC 24v/M50B27
• BMW/320, 520, Z3/DOHC 24v/M52B20
• BMW/325, 525, Z4/DOHC 24v/M50B25
• BMW/325, 525, Z4/DOHC 24v/M52B25
• BMW/325, 525, Z4/DOHC 24v/M54B25