ACL Bearings 4B2756-.25 Race Series Conrod Bearing Set Undersize - 0.25mm

The ACL Bearings 4B2756-.25 is a high-performance connecting rod bearing set designed for demanding engine builds and racing applications. This Race Series bearing set features 0.25mm undersize dimensions to accommodate crankshafts that have been precision-machined or reground, ensuring proper bearing clearance in rebuilt performance engines.

Advanced Tri-Metal Construction:

ACL Race Series bearings utilize a tri-metal layering system that combines a hardened steel backing with a durable copper-lead alloy intermediate layer and a thin overlay surface. This advanced construction provides excellent conformability and embedability, allowing the bearings to absorb small debris and contaminants without damage while maintaining optimal oil film thickness under high loads and RPM.

Performance Features:

• High-strength overlay plate with reduced thickness for superior fatigue resistance
• Hardened steel backing provides robust structural support
• Increased crush for secure retention and heat transfer
• Tight wall tolerances ensure consistent bearing clearances
• Optimized oil grooves and distribution channels for enhanced lubrication
• Improved heat conduction to prevent bearing failure under extreme conditions
• Enlarged chamfers where applicable to accommodate performance crankshaft fillet radii

ACL Race Series bearings are engineered for high-performance street engines, forced induction applications, and full competition race engines. These bearings meet the demands of elevated RPM, increased cylinder pressures, and extended operating temperatures. Proper installation requires measuring bearing clearances with micrometers or plastigage following standard engine building practices.