Clevite MS-2039P-.25MM High Performance Main Bearing Set Oversize

The Clevite MS-2039P-.25MM is a high-performance main bearing set featuring P-Series construction designed for extreme racing and performance applications. This bearing set features a .25mm (.010") oversize dimension to accommodate machined crankshaft journals.

P-Series Performance Design:

• Maximum eccentricity for narrow bearing contact patterns and reduced heat buildup
• Full groove upper shells for maximum oil flow to connecting rod bearings
• Hardened steel backing for superior strength and fretting resistance
• High crush design ensures maximum retention in high-RPM applications
• Reduced overlay thickness prevents overlay fatigue and "hen tracking"
• Unplated bearing backs for improved seating and heat transfer

Optimized Bearing Groove Design:

Features a 180-degree groove in the upper main shell only, which extensive testing has proven to be the most effective design for performance engines. This configuration maximizes oil film thickness on the loaded lower bearing surface while providing adequate oil supply to connecting rod bearings through the upper shell groove.

When to Use P-Series Bearings:

• Extremely high RPM applications experiencing severe rod bore distortion
• Engines showing evidence of rod bearing oil starvation
• Applications requiring higher eccentricity to narrow contact patterns
• Racing engines where maximum oil flow to rod bearings is critical

P-Series bearings utilize Clevite's legendary tri-metal construction with copper-lead bearing surface and lead-tin-copper overlay for exceptional load capacity and durability. The higher eccentricity design makes these bearings ideal for addressing rod bearing lubrication issues common in extreme performance applications.