King Engine Bearings MB4555MC020 Main Bearing Set Undersize - 0.020

The King Engine Bearings MB4555MC020 is a complete main bearing set designed for engine rebuilding applications requiring a 0.020-inch (0.50mm) undersize crankshaft. This set is engineered to restore proper oil clearances when mating to a reground crankshaft, making it an essential component in any quality engine rebuild.

King Engine Bearings has specialized exclusively in engine bearings since 1960, applying race-proven engineering to every bearing in their lineup. Each bearing in this set is manufactured to exacting tolerances, supporting reliable crankshaft rotation, proper oil film maintenance, and long-term engine durability.

Key Features:

• 0.020-inch undersize — designed for use with reground crankshaft journals machined 0.020" under standard diameter
• Precision wall thickness tolerances held to ±0.0001" for consistent, reliable oil clearance
• High-quality bearing material on a steel backing for strength and embedability
• Complete set includes all main bearings required for a full engine installation
• Manufactured to OE dimensional standards for a precise, drop-in fit during engine assembly
• Engineered for street, fleet, and general performance rebuilding applications

King's singular focus on engine bearings means every set benefits from decades of material science and manufacturing innovation. The MB4555MC020 main bearing set delivers the precision fit and durability expected from a world-class bearing specialist, making it a trusted choice for professional engine builders and serious DIY rebuilders alike.