ACL Bearings 5M5647HX-STD Race Series Tri-Metal Main Bearings

ACL Race Series Main Bearings deliver high-performance tri-metal construction engineered to withstand extreme RPM conditions and demanding racing applications. These precision-machined main bearings feature both upper and lower shells for complete crankshaft support.

Key Performance Features:

• High-strength overlay plate with reduced thickness for superior fatigue resistance under extreme loads
• Hardened steel backing improves bearing lining support and ensures positive retention in the housing
• Increased crush provides improved bearing retention and prevents bearing spin
• Flash plating eliminated on bearing backs to maximize heat transfer and improve grip between bearing and housing
• Increased eccentricity compensates for bore distortion at high RPM and promotes hydrodynamic oil film formation
• 3/4 groove design optimizes load-carrying surface area while maintaining proper oil flow to connecting rod bearings
• Tight wall tolerances ensure consistent bearing clearances for reliable performance
• Enlarged ID chamfers accommodate large fillet radius performance crankshafts

ACL's unique combination of advanced metallurgy and precision engineering makes these tri-metal main bearings ideal for high-performance and racing engines where reliability and durability are critical.