King Engine Bearings MB5367SI0.25 SI-Series Main Bearing Set Undersize - 0.25mm

The King Engine Bearings MB5367SI0.25 is a complete crankshaft main bearing set from King's SI-Series lineup, engineered for OE-quality engine rebuilding. Machined to a 0.25mm (0.010 in.) undersize, this set is designed for use during engine rebuilds where the crankshaft has been reground to accommodate the tighter tolerance.

SI-Series Bi-Metal Silicon Aluminum Construction:

• Material: Bi-metal silicon aluminum — an aluminum-based alloy strengthened with approximately 3% silicon for enhanced durability
• Compatibility: Specifically engineered for medium-load engines and nodular cast iron crankshafts
• Improved Surface Finish: Helps reduce microscopic ferrite peaks on improperly ground or polished nodular cast iron crankshafts
• Optimized Oil Clearance: Improved oil clearance geometry reduces wear and increases engine life while lessening operating noise, vibration, and excess oil flow
• Lead-Free Construction: Silicon aluminum formulation is free of lead, making it a more environmentally responsible choice
• Cost-Effective Upgrade: Delivers performance characteristics that can serve as a viable alternative to traditional tri-metal bearing options

King's SI-Series main bearings are recommended for OE replacement applications, including aftermarket gasoline engine rebuilding and performance engines equipped with factory crankshafts. Each bearing in the set is manufactured to King's precision tolerances for consistent wall thickness and dimensional accuracy throughout the complete set.