King Engine Bearings MB512XPSTDX XP Series Tri-Metal Main Bearing Set Ford BDA

The King Engine Bearings MB512XPSTDX is an XP Series main bearing set engineered for the Ford BDA engine in high-performance and racing applications. Built around King's advanced pMax Black tri-metal construction, these bearings deliver 24% greater hardness than conventional tri-metal race bearings, making them the benchmark choice for builds using forged steel aftermarket crankshafts under sustained high-load conditions.

The XP Series was developed specifically for performance environments that demand more than standard bearings can provide — including circle track, off-road, offshore racing, and other long-duration, high-load disciplines. Advanced metallurgical and geometric technologies work together to handle extreme loads and RPM levels that would compromise lesser bearings.

pMax Black Tri-Metal Construction:

• Enhanced tri-metal copper-lead construction with nickel barrier layer
• SecureBond adhesion process ensures superior stability between the top and intermediate layers
• 0.0005" metallurgically enhanced and hardened performance overlay for superior fatigue resistance
• 24% harder than conventional tri-metal race bearings
• 15%–30% greater load capacity than traditional bearings

XP Series Geometric Features:

• Bull's Eye Tolerance: All shells matched to 0.0001" — the tightest wall tolerances in the industry
• Improved Oiling: Enlarged, chamfered oil holes for enhanced lubrication flow
• Medium Eccentricity: Optimizes load distribution and improves oil film maintenance
• Narrowed Design: Mains and rods narrowed to accommodate large-radius crankshafts
• Half-Grooved Mains: Upper shell grooved, lower shell ungrooved to preserve full lower-shell load capacity
• Dowel Holes: Available with or without dowel holes depending on application

King Engine Bearings offers the industry's widest selection of sizes and special clearance options, ensuring the right fit for the most demanding performance builds. The MB512XPSTDX is supplied in standard (STD) sizing.