King Engine Bearings MB639XPSTDX XP Series Tri-Metal Main Bearing Set Standard Extra Clearance

The King Engine Bearings MB639XPSTDX is a high-performance XP Series tri-metal main bearing set designed for demanding racing and performance applications. This bearing set features standard sizing with extra oil clearance (STDX designation provides an additional 0.001" clearance), making it ideal for engines with modified clearances or high-performance builds requiring increased oil flow.

Key Features:

• Tri-metal construction with copper-lead intermediate layer for superior load capacity and durability
• pMax Black coating provides enhanced fatigue resistance and 24% harder overlay than conventional tri-metal bearings
• Standard size with extra 0.001" oil clearance (STDX) for performance applications
• Designed for steel crankshafts in high-load, long-duration racing environments
• Bull's Eye bearing wall tolerance of ±0.0001" ensures consistent fitment and performance
• Load capacity rating of 10,200 PSI in the overlay layer
• Ideal for circle track, drag racing, and other motorsports applications

King Engine Bearings has been manufacturing precision engine bearings since 1960, focusing exclusively on bearing technology to deliver the highest quality products available. The XP Series represents King's advanced metallurgical technology specifically engineered for performance engines using forged steel aftermarket crankshafts. These bearings are race-proven and trusted by professional engine builders for their exceptional load capacity, precision tolerances, and long-term durability under extreme conditions.