Clevite MS-2252P-20 P-Series High Performance Main Bearing Set

The Clevite MS-2252P-20 is a high-performance main bearing set from the legendary P-Series line, engineered for extreme RPM applications and maximum oil flow to connecting rod bearings. This main bearing set features full 360-degree grooving to maximize oil delivery to rod bearings, making it ideal for high-stress racing engines where rod bearing lubrication is critical.

P-Series Performance Features:

• Full groove design maximizes oil flow to connecting rod bearings
• High crush design ensures maximum bearing retention under extreme conditions
• Reduced overlay thickness prevents overlay fatigue and "hen tracking"
• Hardened steel back construction for added strength and fretting resistance
• Greater eccentricity to narrow bearing contact patterns and improve oil distribution
• TriMetal bearing construction for legendary Clevite strength and durability

Engineered for Racing Applications:

P-Series bearings are Clevite's oldest and most proven high-performance bearing line. The increased eccentricity design is specifically intended for engines experiencing severe rod bore close-in at extremely high RPMs, typically indicated by nearly full parting line contact. The full groove configuration prioritizes oil delivery to prevent rod bearing starvation, which commonly manifests as surface polishing, smearing, and discoloration concentrated at the bearing's axial center.

Understanding Main Bearing Groove Technology:

Main bearing grooving serves a critical function: delivering oil to connecting rod bearings. Modern bearing engineering has proven that a 180-degree groove in the upper main shell provides optimal performance, as the upper shell experiences lower loads than the lower shell. The P-Series utilizes full 360-degree grooving specifically to maximize oil flow in high-performance applications where rod bearing lubrication is paramount, even though this design slightly reduces oil film thickness compared to partial-groove designs.

When to Choose P-Series:

Select P-Series main bearings when your engine operates at extremely high RPMs causing severe rod bore deformation, when you need maximum rod bearing oil delivery, or when previous bearing analysis shows signs of rod bearing oil starvation. If you're experiencing narrow contact patterns with H-Series or other lower-eccentricity bearings, P-Series provides the increased eccentricity needed for proper load distribution.

This bearing set includes upper and lower main bearing shells with the precision tolerances and material specifications required for professional racing and high-performance street applications.