Clevite MS-1568P-20 High Performance P-Series Main Bearing Set

The Clevite MS-1568P-20 is a high-performance P-Series main bearing set designed for racing and extreme-duty engine applications. This bearing set features full 360-degree grooving to maximize oil flow to connecting rod bearings, making it ideal for engines requiring enhanced lubrication under demanding conditions.

P-Series Performance Features:

• High crush design for maximum bearing retention and stability
• Reduced overlay thickness to prevent overlay fatigue and "hen tracking"
• Full groove configuration for superior oil delivery to rod bearings
• Hardened steel back construction for added strength and fretting resistance
• Greater eccentricity to narrow bearing contact patterns and improve oil distribution
• Tri-Metal construction combining durability with performance

When to Use P-Series Bearings:

P-Series main bearings are the optimal choice for high-RPM racing engines where rod bearing oil starvation is a concern. These bearings excel in applications requiring maximum oil flow to the connecting rods, particularly where rod bearings show signs of oil starvation such as surface polishing, smearing, or discoloration concentrated at the bearing's axial center. The higher eccentricity design produces narrower contact patterns that enhance oil delivery while maintaining proper load distribution.

Technical Design:

This bearing set utilizes a 180-degree groove in the upper main shell, which engineering testing has proven to be the optimal design for bearing performance. The groove provides essential oil supply to connecting rods while maintaining maximum oil film thickness in critical load zones. The lower main shells are ungrooved, allowing for a thicker oil film and improved bearing life under load.

P-Series bearings are manufactured without flash plating for superior seating characteristics and feature enlarged chamfers for improved crankshaft fillet clearance. These bearings are specifically engineered for engines experiencing severe rod bore close-in at extremely high RPMs, typically indicated by nearly full parting line-to-parting line shaft contact with standard bearings.