King Engine Bearings MB5781SI Main Bearing Set Bi-Metal Silicon Aluminum

The King Engine Bearings MB5781SI is a precision-engineered main bearing set designed for Nissan MR18DE and MR20DE engines, as well as Renault M4R 700/01/04 engines. This complete main bearing set provides the critical interface between your engine block and crankshaft, ensuring smooth rotation and reliable engine performance.

Advanced Bi-Metal Construction:

These bearings feature King's proven bi-metal silicon aluminum design, utilizing an aluminum-based material strengthened with 2.5-3% silicon content. This specialized alloy composition is specifically engineered for medium-load engines and provides excellent compatibility with nodular cast iron crankshafts, delivering superior wear resistance and longevity.

Key Features:

• Precision main bearing set for complete crankshaft support
• Bi-metal silicon aluminum construction with 2.5-3% silicon reinforcement
• Optimized for medium-load engine applications
• Excellent compatibility with nodular cast iron crankshafts
• Engineered for Nissan MR18DE, MR20DE, and Renault M4R 700/01/04 engines
• Manufactured to OE specifications for precise fit and performance

King Engine Bearings is renowned for producing high-performance engine bearings that meet or exceed OEM standards. This main bearing set is ideal for engine rebuilds, performance applications, or replacement during routine maintenance.