ACL Bearings 5M5647H-.025 Race Series Tri-Metal Main Bearings

ACL Race Series Main Bearings are engineered for high-performance and racing applications where extreme RPM and cylinder pressures demand superior durability and reliability. These tri-metal main bearings feature both upper and lower shells with advanced metallurgy and precision manufacturing to deliver consistent performance under the most demanding conditions.

Key Features:

• High-strength overlay plate with reduced thickness for improved fatigue resistance and longevity
• Hardened steel backing on all bearings provides enhanced support for the bearing lining and improved retention in the housing
• Increased crush ensures superior bearing retention and stability during high-RPM operation
• Elimination of flash plating on bearing backs maximizes heat transfer and improves grip between bearing and housing
• Increased eccentricity compensates for bore distortion at high RPM and promotes optimal hydrodynamic oil film formation
• 3/4 groove design on main bearings optimizes load-carrying surface area while maintaining proper oil flow to connecting rod bearings
• Tight wall tolerances allow precise control of bearing clearances for consistent performance
• Enlarged ID chamfers on bearing edges accommodate large fillet radii common on performance crankshafts

ACL Race Series bearings combine advanced design, premium materials, and precision engineering to deliver the performance and durability that racers and performance enthusiasts demand. The -.025 undersize is designed for crankshafts that have been machined .025" undersize on the main journals.