Clevite MS-178P-30 High Performance Main Bearing Set P-Series

The Clevite MS-178P-30 is a high-performance main bearing set engineered for demanding racing and competition applications. This P-Series bearing set features full groove design to maximize oil flow to connecting rod bearings, making it ideal for engines experiencing rod bearing oil starvation.

P-Series Performance Features:

• Full grooved upper shells for maximum oil delivery to connecting rods
• High crush design for superior bearing retention in extreme conditions
• Reduced overlay thickness to prevent overlay fatigue and "hen tracking"
• Hardened steel backing for added strength and fretting resistance
• Greater eccentricity to narrow bearing contact patterns and improve lubrication
• Engineered for extremely high RPM applications with severe rod bore close-in

Advanced Bearing Technology:

Clevite main bearings utilize proven TriMetal construction with optimized groove designs. The 180-degree groove in the upper shell provides the best overall performance by maintaining oil film thickness while supplying adequate lubrication to connecting rods. The ungrooved lower shell develops a thicker oil film for improved load capacity and bearing life.

When to Use P-Series:

Select P-Series main bearings when you need maximum eccentricity to address narrow contact patterns or when rod bearings show signs of oil starvation (polishing, smearing, or discoloration at the axial center). These bearings excel in high-RPM racing engines where extreme loads demand superior retention and oil delivery. P-Series bearings are also available with extra clearance options for precision select fitting.

This bearing set represents decades of Clevite engineering expertise in competition engine bearing design, delivering reliable performance under the most severe operating conditions.