ACL Bearings 1B634H-09 Race Series Connecting Rod Bearing - Set

The ACL 1B634H-09 represents a precision-engineered connecting rod bearing from ACL's Race Series lineup, combining advanced design, metallurgy and engineering to deliver high-performance trimetal engine bearings designed to withstand higher RPM conditions. This bearing features tri-metal construction with hardened steel backs and comes as identical halves with standard oil clearance.

Key Features:

• High strength overlay plate with reduced thickness for improved fatigue properties, plus hardened steel backs on all rod bearings to improve support and assist with bearing retention
• Elimination of flash plating on bearing backs to improve heat transfer and maximize grip, with increased eccentricity to compensate for bore distortion at high RPM
• Race Series bearings are 0.0005 inch thinner per half to provide 0.001 inch extra clearance for standard sized crankshafts
• Tight consistent wall tolerances to maintain consistent clearances, with enlarged ID chamfers on bearing edges to accommodate large fillet radius on performance crankshafts
• P76 overlay for superior abrasion and fatigue resistance, plus CT-1 coating by Calico dry film lubricant for reduced friction and wear protection

Technical specifications include shaft size compatibility of 2.1228-2.1236 inches (53.919-53.939mm), tunnel size of 2.2390-2.2398 inches (56.871-56.891mm), maximum wall thickness at crown of 0.0574 inches (1.458mm), and maximum overall length of 0.726 inches (18.44mm). ACL Race series performance bearings are engineered for extreme endurance under harsh conditions, where fatigue, stress wear, and failure are minimized through top-tier metallurgy.

ACL is an engine builder's top choice for quality and consistency, trusted as an Original Equipment supplier found in many racing applications. The -09 suffix denotes the specific undersize variation within the 1B634H series.