ACL Bearings 5M1948P-30 Engine Main Bearing Set Undersize - 0.030

The ACL Bearings 5M1948P-30 is a precision-engineered engine main bearing set manufactured to strict dimensional tolerances. This set features a 0.030" undersize specification, designed for use during engine rebuilds where crankshaft journals have been machined and require undersized bearings to restore proper oil clearance and fit.

ACL Bearings are produced using advanced tri-metal construction technology, combining a steel backing, intermediate bonding layer, and a precision overlay that delivers excellent load capacity, conformability, and wear resistance — making them a trusted choice for professional engine builders and performance rebuilds alike.

Key Features:

• 0.030" (0.762mm) Undersize — engineered for reground or turned crankshaft main journals
• Tri-metal construction — steel-backed with precision bearing overlay for durability and long service life
• High load capacity — designed to handle the demands of both stock and mildly performance-built engines
• Precision tolerance manufacturing — ensures correct oil film thickness and clearance for optimal lubrication
• Complete set — includes all main bearing shells required for a full engine installation
• OEM-quality fitment suitable for professional engine rebuild applications

ACL Bearings are an ISO-certified manufacturer with decades of experience supplying the global automotive aftermarket. The 5M1948P-30 main bearing set is the ideal solution for restoring worn or damaged main bearing journals to factory-spec performance during a professional engine overhaul.