Clevite MS-909P-20 P-Series High Performance Main Bearing Set

The Clevite MS-909P-20 is a P-Series high performance main bearing set designed for engines operating at extremely high RPMs where maximum oil flow to connecting rod bearings is critical. This bearing set features full 360-degree grooving in the upper shells to maximize oil delivery to the rod bearings, making it ideal for severe racing applications.

P-Series Performance Features:

• Full grooved upper shells for maximum oil flow to connecting rod bearings
• High crush design for maximum retention in the bore
• Reduced overlay thickness to prevent overlay fatigue and hen tracking
• Greater eccentricity to narrow bearing contact patterns and increase rod bearing oiling
• TriMetal construction with hardened steel back for added strength
• No flash plating for improved seating characteristics

When to Use P-Series Main Bearings:

P-Series main bearings are specifically engineered for extreme RPM applications where rod bearing oil starvation is a concern. Choose P-Series mains when you need higher eccentricity to narrow contact patterns and provide increased oil delivery to rod bearings. These bearings are ideal when rod bearing oil starvation is indicated by polishing, smearing, or discoloration concentrated at the axial center of the bearings.

Technical Design:

Clevite's extensive testing has shown that while modern engines benefit from removing grooving in lower main shells to create a thicker oil film, upper main shells require grooving to supply connecting rods with oil. P-Series bearings use full 360-degree grooving to maximize this oil supply in high-performance applications where rod bearing lubrication is critical.

These are genuine Clevite 77 high performance bearings with unique core part numbers, not to be confused with standard passenger car replacement parts. The MS-909P-20 represents decades of bearing engineering expertise specifically tailored for competition and severe-duty applications.