ACL Race Series main bearings for Nissan SR20DET
Fits
Nissan
Universal- Shipping in 24-48 hSubject to availability
- 14 days to returnUnfitted and in its original packaging
- Pay in instalmentsFinance your purchase at checkout
- Collection at our shopCartagena, Spain
ACL Race Series main bearing set for Nissan SR20DET, part number 5M2964H. These support the crankshaft in the block and, in a tuned engine, are essential for ensuring oil reaches the entire crankshaft properly.
The structure is tri-metal, with a steel base, copper-lead-tin lining, a nickel barrier, and a soft surface layer that adapts and prevents seizing even under very high loads.
The upper bearings feature a full 180° oil groove, while the lower ones have a partial groove to avoid interrupting oil flow to the connecting rods; the end of the groove is tapered to prevent pressure spikes. ACL manufactures them with more "crush" (interference fit) than standard bearings to ensure they are held securely and dissipate heat more effectively, and with more eccentricity, which helps maintain the oil film when the housing deforms at high RPMs.
In standard size, ACL specifies this for a crankshaft journal of 54.956 to 54.980 mm, and for that diameter, recommends an oil clearance of approximately 0.057 to 0.068 mm. If the crankshaft has been reground, the measurement changes.
These do not have the silver tin top layer of standard bearings, so their dark, brownish-black and bluish color is the factory finish and does not indicate any defect. ACL advises against polishing the bearing surface to adjust clearance; if more is needed, they can be combined with the HX version, which provides an additional 0.025 mm of clearance.
Before ordering, please confirm your crankshaft measurement (standard or reground); if you have any questions, write to us with your engine code.