ACL Bearings 5M5647H-.25 Race Series Tri-Metal Main Bearings

ACL Race Series Main Bearings are engineered for high-performance engines operating under extreme RPM and load conditions. These tri-metal bearings feature both upper and lower halves with advanced metallurgy designed to deliver superior durability and reliability in racing applications.

Key Features:

• High-strength overlay plate with reduced thickness for improved fatigue resistance and longevity
• Hardened steel backing on all bearings to enhance support of the bearing lining and improve retention in the housing
• Increased crush for superior bearing retention and security
• No flash plating on backing to maximize heat transfer and improve grip between bearing and housing
• Increased eccentricity to compensate for bore distortion at high RPM and promote hydrodynamic oil film formation
• 3/4 groove design on main bearings to optimize load-carrying surface area and ensure proper oil flow to connecting rod bearings
• Tight, consistent wall tolerances for precise bearing clearance control
• Enlarged ID chamfers on bearing edges to accommodate large fillet radius on performance crankshafts

The -.25 designation indicates this bearing set is designed for 0.25mm undersize applications. ACL's unique combination of design, metallurgy, and engineering delivers the performance and durability demanded by competitive racing engines.