Clevite MS-1277HG High Performance Main Bearing Set with 360° Grooving

The Clevite MS-1277HG is a high-performance engine crankshaft main bearing set featuring full 360-degree grooving for maximum oil flow to connecting rod bearings. Designed for demanding racing and performance applications, this bearing set delivers the durability and strength needed for high-RPM operation.

H-Series Performance Features:

• Medium eccentricity design with high crush for maximum retention
• Hardened steel backing for added strength and resistance to fretting
• Thin overlay construction to prevent overlay fatigue
• Enlarged chamfers for greater crankshaft fillet clearance
• Full 360-degree grooving (HG designation) maximizes oil delivery to rod bearings
• No flash plating for improved bearing seating
• Legendary Clevite TriMetal construction for superior durability

Application Guidance:

H-Series bearings were developed primarily for NASCAR-type racing but are suitable for all types of competition engines. Use this bearing set with crankshafts that have oversize fillets and where engines operate in medium to high RPM ranges. The full 360-degree grooving pattern ensures optimal oil supply to connecting rod bearings in applications where maximum lubrication is critical. Contact patterns should ideally cover 2/3 to 3/4 of the bearing surface for optimal performance.

Technical Design:

The 360-degree grooving provides continuous oil feed throughout the bearing circumference, making this design ideal for applications experiencing rod bearing oil starvation. While standard H-Series bearings feature 180-degree upper half grooving, the HG variant extends grooving around the full bearing for maximum oil delivery capacity. This design is particularly beneficial in high-load, high-RPM applications where connecting rod bearing lubrication is paramount.