Clevite MS-1266A-30 Engine Crankshaft Main Bearing Set

The Clevite MS-1266A-30 is a high-performance engine crankshaft main bearing set engineered to deliver superior durability and optimal oil film protection in demanding applications. This precision-manufactured bearing set utilizes Clevite's legendary TriMetal construction, combining a steel backing with a copper-lead intermediate layer and a lead-tin-copper overlay for exceptional strength, conformability, and wear resistance.

Key Features:

• TriMetal construction with hardened steel backing for maximum strength and fretting resistance
• Optimized bearing grooving design to maintain critical oil film thickness while ensuring adequate connecting rod lubrication
• High crush design for superior bearing retention in high-RPM applications
• Reduced overlay thickness to prevent overlay fatigue and hen tracking
• Enlarged chamfers for increased crankshaft fillet clearance
• Non-flash plated backing for improved seating and heat transfer
• Precision-engineered eccentricity for proper load distribution and contact patterns

Performance Benefits:

Clevite performance main bearing sets are designed with oil film optimization in mind. The upper shells feature a 180-degree groove to supply oil to connecting rod bearings while maintaining maximum film thickness. Lower shells are ungrooved to provide the thickest possible oil film where loads are highest, resulting in improved bearing life and greater safety margins in high-performance engines.

Applications:

Ideal for performance street engines, racing applications, and rebuilt engines requiring maximum durability. Compatible with standard and performance crankshafts. Suitable for engines operating in medium to high RPM ranges where bearing reliability is critical.

Installation Notes:

Proper bearing clearances must be verified during installation using Plastigage or micrometers. Contact patterns should ideally cover 2/3 to 3/4 of the bearing surface for optimal performance. Always use appropriate assembly lubricant during installation and follow manufacturer torque specifications.