Extra Clearance ACL Rod Bearing Set - S65 V8 - BMW M3 E90/92/93

Rod-bearing wear is the known weak point in the S65 bottom end — the high-revving V8 loads them hard, and worn shells are what end most of these engines. This is the extra-clearance ACL Race Series set: the same Tri-Metal design run in serious builds, supplied with additional oil clearance to give the S65 more margin under sustained high-rpm load.

Part number: 8B1580HX-STD

Construction and why it matters:

• Tri-Metal lead/copper: a steel backing coated with copper and topped with a soft lead overlay. The lead is embeddable: small particles bed into it instead of scoring the crankshaft.
• High-strength overlay plate, reduced thickness, for improved fatigue life.
• Hardened steel backs support the bearing lining and hold retention in the housing.
• Increased crush for better retention under load.
• No flash plating on the backs: improves heat transfer into the housing and grip between bearing and housing.
• Increased eccentricity compensates for bore distortion at high rpm and helps form the hydrodynamic oil film.
• Tight, consistent wall tolerances to hold consistent clearances.
• Enlarged ID chamfers to clear the large fillet radii on performance crankshafts.

Fits: E9X M3 (S65), M3 E90/E92/E93