ACL Race Series Reinforced Main Bearings - Nissan RB20/25/30 & RD28

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 Main 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

• Holden/Calais, Commodore VL/SOHC 12v/Nissan RB30E
• Holden/Calais, Commodore VL/SOHC 12v Turbo/Nissan RB30ET
• Nissan/Cefiro, Skyline R31, Commodore VL (NZ)/SOHC 12v/RB20E, RB20S
• Nissan/Cefiro, Skyline R32/DOHC 24v/RB20DE
• Nissan/Cefiro, Skyline R32/DOHC 24v Turbo/RB20DET
• Nissan/Skyline R33/DOHC 24v/RB25DE
• Nissan/Skyine R33/DOHC 24v/RB25DET
• Nissan/Patrol GQ, GQII/SOHC 12v/RB30S
• Nissan/Skyline, Holden Calais, Commodore VL/SOHC 12v/RB30E
• Nissan/Holden Calais, Commodore VL/SOHC 12v Turbo/RB30ET
• Nissan/Patrol GQII, GU/SOHC 12v Turbo Diesel/RD28T
• Nissan/Skyline R31, Laurel, Cedric/SOHC 12v Diesel/RD28
• Nissan/Skyline R31, Laurel, Cedric/SOHC 12v Diesel/RD28E