ACL Bearings 4B1972HD-.025 Race Series Rod Bearing Set .025mm Oversize with Dowel Holes

The ACL Bearings 4B1972HD-.025 is a high-performance Race Series connecting rod bearing set designed for Honda/Acura K20A2, K20Z1, K24A, and K24Z1 engines. This .025mm (.001 inch) oversize bearing set features dowel hole locations for precise alignment and is engineered to withstand the extreme demands of high-performance and racing applications.

Key Features:

• Tri-metal construction with high-strength steel backing for superior strength and retention
• Dowel hole location (HD designation) for precise bearing positioning
• .025mm oversize for reground crankshafts
• Hardened steel backs on all rod bearings improve support and assist with bearing retention
• High-strength overlay plate with reduced thickness for improved fatigue resistance
• No flash plating on bearing backs to maximize heat transfer and improve bearing-to-housing contact
• Increased eccentricity compensates for bore distortion at high RPM
• Tight, consistent wall tolerances help maintain proper clearances
• Enlarged ID chamfers accommodate large fillet radius on performance crankshafts

ACL Race Series bearings are manufactured to exacting tolerances using micron-level precision machining and measurement systems. The unique combination of advanced metallurgy, precise engineering, and performance-oriented design makes these bearings the choice of professional engine builders and racers who demand reliability under harsh conditions including high RPM, elevated temperatures, and extreme loads.