Clevite MS-2220A-.25MM Engine Crankshaft Main Bearing Set

The Clevite MS-2220A-.25MM is a high-performance engine crankshaft main bearing set designed for demanding applications. This -.25mm undersize bearing set features precision-engineered construction to maintain optimal oil film thickness and bearing longevity.

Advanced Bearing Design:

Modern main bearing technology has evolved to optimize oil film development. The upper main shells feature a 180-degree groove design to efficiently supply oil to connecting rod bearings, while the lower shells remain ungrooved to maximize oil film thickness and load capacity. This configuration provides the best balance of lubrication distribution and bearing durability, as extending grooves into the lower bearing half reduces performance without providing additional benefits.

Series-Specific Engineering:

Clevite offers multiple bearing series to match specific performance requirements. P-Series bearings provide maximum eccentricity with full grooving for extreme RPM applications and enhanced rod oiling. H-Series bearings feature medium eccentricity, enlarged chamfers for oversize crankshaft fillets, and hardened steel backs without flash plating for superior seating. K-Series bearings incorporate proprietary moly/graphite TriArmor coating for exceptional wear protection across broad temperature ranges. V-Series bearings utilize lead-indium overlay for superior conformability, while M-Series micro bearings offer .006-inch babbitt lining for maximum conformability in high-deflection applications.

Key Features:

• -.25mm undersize for precision crankshaft machining
• Optimized groove design for maximum oil film development
• High crush construction for secure bearing retention
• Reduced overlay thickness prevents fatigue and hen tracking
• Hardened steel backing provides exceptional strength
• Enlarged chamfers available for increased fillet clearance
• TriMetal construction for durability and load capacity

Proper bearing selection depends on specific engine characteristics including RPM range, crankshaft fillet size, and observed bearing contact patterns. Ideal contact patterns should cover 2/3 to 3/4 of the bearing surface for optimal performance and longevity.