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files/ACL_Race_Series_main_bearing_set_for_BMW_N54_N55_S55B30.jpg
Upgrade your bottom end with ACL Race Series tri-metal main bearings, engineered for high-RPM performance and forced-induction reliability. Steel-backed with copper-lead-tin lining for improved fatigue strength and retention, increased crush for better retention, and enlarged ID chamfers to clear performance crankshaft fillets.
Fits: BMW N54B30, N55B30, S55B30 (3.0L Inline-6)
- Standard — stock, unworn crank journals
- Standard HX — same size as standard, +0.001" extra clearance, for built engines running higher oil temps/RPM
- 0.025mm Undersize — fine trim, minor crank cleanup
- 0.25mm Undersize — first regrind step
- 0.50mm Undersize — second regrind step
⚠️ Before ordering an undersize set, confirm your crank has been machined to the matching undersize spec — check clearances with Plastigauge before final assembly.
ACL
ACL Race Series Main Bearing Set - BMW N54/N55/S55B30
- Regular price
- $256.99
Confirm the application before installation. European engine components can vary by engine code, production date, chassis and component size.
- Verify the engine code and vehicle application.
- Match the manufacturer part number / SKU shown for the selected item.
- Confirm STD, undersize, oversize or other required dimensions where applicable.
Upgrade your bottom end with ACL Race Series tri-metal main bearings, engineered for high-RPM performance and forced-induction reliability. Steel-backed with copper-lead-tin lining for improved fatigue strength and retention, increased crush for better retention, and enlarged ID chamfers to clear performance crankshaft fillets.
Fits: BMW N54B30, N55B30, S55B30 (3.0L Inline-6)
- Standard — stock, unworn crank journals
- Standard HX — same size as standard, +0.001" extra clearance, for built engines running higher oil temps/RPM
- 0.025mm Undersize — fine trim, minor crank cleanup
- 0.25mm Undersize — first regrind step
- 0.50mm Undersize — second regrind step
⚠️ Before ordering an undersize set, confirm your crank has been machined to the matching undersize spec — check clearances with Plastigauge before final assembly.
