ACL Bearings 8B663HN-010 Race Series Narrowed Rod Bearing Set .010" Undersize Small Block Chevy

The ACL Bearings 8B663HN-010 is a high-performance narrowed connecting rod bearing set designed for Small Block Chevrolet V8 engines including 262, 267, 302, 305, 307, 327, 350, and 400ci applications, as well as LS-series engines (4.8L, 5.3L, 5.7L LS1/LS6, 6.0L LS2, and 6.2L LS3). This Race Series H-Series bearing set is manufactured to .010" undersize specifications and features a narrowed design for additional edge clearance when running crankshafts with exceptionally large fillet radii.

ACL Race Series performance engine bearings are recognized as a premier brand throughout the motorsports world, with Race Series bearings being standard components in engines that have set records and won championships from drift racing to NASCAR, IHRA, and NHRA competitions. The unique combination of design, metallurgy, and engineering provides Race Series bearings with the endurance and capability to perform where others cannot.

Key Features

• Narrowed bearing shells (HN designation) provide extra edge clearance for large fillet radius crankshafts
• .010" undersize for reground crankshaft journals
• Trimetal construction with lead, tin, copper, and nickel for superior strength and seizure resistance
• Hardened steel backing on all rod bearings for improved lining support and bearing retention
• High-strength overlay plate with reduced thickness for improved fatigue properties
• Elimination of flash plating on bearing backs improves heat transfer and maximizes grip in housing
• Increased eccentricity compensates for bore distortion at high RPM and assists in hydrodynamic oil film formation
• Tight, consistent wall tolerances help maintain precise clearances
• Enlarged ID chamfers accommodate large fillet radius on performance crankshafts

Technical Specifications

• Application: Small Block Chevrolet V8 (262-400ci) and LS-series engines
• Bearing Type: Connecting Rod Bearing Set
• Series: ACL Race Series H-Series Narrowed (HN)
• Size: .010" Undersize
• Construction: Trimetal (lead-tin-copper-nickel alloy)
• Steel Backing: SAE1010 high tensile hardened steel
• Overlay Thickness: 0.013-0.018mm (0.0005"-0.0007")
• Barrier Layer: Nickel (0.001mm/0.00004")
• Lining Thickness: 0.3mm (0.012")

The H-Series designation indicates these are ACL's premium race-grade bearings, engineered specifically for high-RPM racing applications where durability and performance are critical. The narrowed design makes these bearings ideal for stroker builds or applications using crankshafts with larger than standard fillet radii, preventing bearing edge interference while maintaining proper oil clearances.