Clevite MS-2009P-.25MM Main Bearing Set Undersize Performance Engine Bearings

The Clevite MS-2009P-.25MM is a high-performance main bearing set designed for demanding engine applications. This undersize bearing set (.25mm) provides precision fitment for reground crankshafts while maintaining the superior protection and durability Clevite bearings are known for in racing and performance builds.

P-Series Performance Design:

• High eccentricity design optimizes oil film distribution under extreme loads
• Full groove configuration maximizes oil flow to connecting rod bearings
• High crush for maximum bearing retention in performance applications
• Reduced overlay thickness prevents overlay fatigue and "hen tracking"
• Hardened steel backing provides exceptional strength and fretting resistance
• TriMetal construction with lead-tin-copper overlay for durability

Optimized Bearing Geometry:

Clevite P-Series main bearings feature full grooved upper shells to ensure adequate oil supply to rod bearings in high-RPM applications. The design maintains critical oil film thickness while providing the increased oil flow necessary for performance engines. This geometry is particularly beneficial when rod bearing oil starvation is a concern, typically indicated by polishing and discoloration at the bearing's axial center.

Applications:

P-Series bearings are ideal for extreme high-RPM applications where severe rod bore distortion occurs. Use these bearings when experiencing nearly full parting line contact with standard bearings, or when increased oiling to rod bearings is required. The higher eccentricity design helps narrow bearing contact patterns to the optimal 2/3 to 3/4 coverage range while improving lubrication delivery.

This main bearing set is manufactured without flash plating for improved seating characteristics and features enlarged chamfers for enhanced crankshaft fillet clearance. The undersize dimension (.25mm) accommodates crankshafts that have been ground for journal restoration or performance optimization.