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

BMW S65 V8 ACL Race Series Engine Bearings – Certified Custom Set - +0.0125mm

When it comes to high-performance and motorsports engines, precision isn’t optional—it’s everything. That’s why ACL Race Series engine bearings have been the trusted choice in championship-winning and record-setting builds across drift racing, NASCAR, IHRA, and NHRA.

For S65/S85 engines, mixed ACL bearings (HX and H) have been the go-to solution, but we take precision a step further. Instead of relying on in-house measurements or handheld tools, every single bearing shell is measured and certified by Michigan’s most reputable metrology lab. Using state-of-the-art $150,000 measuring equipment, we ensure each shell meets ACL’s published specifications with absolute accuracy.

Each set is verified to provide an additional clearance of +0.0125mm, eliminating any uncertainty. Bearings that don’t meet spec are rejected—only certified, lab-measured shells make it into our sets.

No assumptions, no guesswork—just certified precision and total reliability. See the full process in action in this video.

ACL Race Series Engine Bearings Key Features:

• Tri-Metal Lead/Copper Design – A hardened steel backing is layered with copper and topped with a soft lead overlay. The lead’s embeddable properties allow small particles to embed without damaging the crankshaft, ensuring long-term reliability.
• High-Strength Overlay Plate – Reduced thickness improves fatigue resistance, making the bearings more durable under extreme loads.
• Hardened Steel Backs – All rod bearings feature a hardened steel backing to enhance bearing support and retention in the housing.
• Increased Crush – Improved crush fit enhances bearing retention, preventing unwanted movement under high stress.
• No Flash Plating – Eliminating flash plating on the bearing backs improves heat transfer and maximizes grip between the bearing and housing.
• Optimized Eccentricity – Increased eccentricity compensates for bore distortion at high RPMs, aiding in the formation of a hydrodynamic oil film for superior lubrication.
• Precision Wall Tolerances – Tight and consistent wall thickness ensures precise clearances for optimal oil flow and performance.

ACL Race Series bearings are engineered for precision, durability, and peak performance, making them the top choice for serious engine builders.