Clevite MS-590P-20 P-Series High Performance Main Bearing Set

The Clevite MS-590P-20 is a high-performance main bearing set from the legendary Clevite 77 P-Series line, engineered specifically for demanding racing and performance applications where maximum oil flow and extreme retention are critical.

P-Series Performance Features:

• Full groove design in upper shells maximizes oil flow to connecting rod bearings
• High crush construction ensures maximum bearing retention under extreme conditions
• Reduced overlay thickness prevents overlay fatigue and hen tracking
• Hardened steel backing provides exceptional strength and resistance to fretting
• Higher eccentricity design narrows bearing contact patterns and increases rod oiling
• TriMetal construction with lead-tin-copper overlay for durability

Optimal Bearing Groove Design:

This bearing set features a 180-degree groove in the upper main shell, proven through extensive testing to provide the best overall performance. This design develops the thickest oil film for maximum bearing life while still supplying adequate lubrication to the connecting rods. The ungrooved lower shells allow the crankshaft to ride on a fuller oil film, providing a greater safety margin compared to older full-grooved designs.

Best Applications:

P-Series main bearings are ideal for high-RPM racing engines where rod bearing oil starvation is a concern, typically indicated by polishing, smearing, or discoloration at the axial center of rod bearings. The increased eccentricity helps maintain proper contact patterns (ideally covering 2/3 to 3/4 of bearing surface) while ensuring maximum oil delivery to heavily loaded rod bearings. These bearings are designed for engines experiencing severe operating conditions where standard bearings cannot provide adequate retention or oiling.

Technical Construction:

Each bearing features Clevite's proven TriMetal design with a hardened steel backing, intermediate layer, and precision overlay. The reduced overlay thickness specifically addresses the challenge of overlay fatigue in high-performance applications. High crush design maintains positive bearing retention even under extreme thermal cycling and vibration loads common in racing environments.