Clevite MS-540H High Performance Engine Crankshaft Main Bearing Set

The Clevite MS-540H is a high-performance main bearing set designed for competition engines and demanding racing applications. This H-Series bearing features an optimized 180-degree upper shell grooving design that maximizes oil film thickness while providing adequate oil supply to connecting rod bearings.

H-Series Performance Features:

• Medium eccentricity profile for balanced contact patterns covering 2/3 to 3/4 of bearing surface
• High crush design ensures maximum bearing retention under extreme loads
• Hardened steel backing provides superior strength and fretting resistance
• Thin overlay construction prevents overlay fatigue and hen tracking
• Enlarged chamfers accommodate oversize crankshaft fillets
• No flash plating for improved bearing seating and bedding
• 180-degree upper shell grooving optimizes oil film development

Technical Design:

H-Series bearings utilize Clevite's proven TriMetal construction with a lead-tin-copper overlay. The 180-degree groove configuration in the upper main shell has been engineered to provide the best overall bearing performance, maintaining thick oil film development on the loaded lower bearing surface while ensuring adequate oil flow to connecting rods. Research has shown that extending grooves into the lower bearing half reduces performance without providing benefits, while the 180-degree design delivers optimal protection.

Applications:

Originally developed for NASCAR racing applications, H-Series bearings are suitable for all types of competition engines operating in medium to high RPM ranges. These bearings are the recommended starting point when selecting performance bearings for engines with oversize crankshaft fillets. They provide broader contact patterns than P-Series bearings and are ideal for applications requiring a balance between oil flow and load capacity.

Installation Notes:

Contact patterns should ideally cover 2/3 to 3/4 of the bearing surface for optimal performance. The enlarged chamfers provide clearance for crankshafts with oversize fillets. The absence of flash plating ensures proper bearing seating during initial break-in.