King Engine Bearings MB5280XP0.5 XP-Series Tri-Metal Main Bearing Set Ford V8 4.6L 5.4L SOHC 0.5mm Undersize

The King Engine Bearings MB5280XP0.5 is a XP-Series performance main bearing set designed for Ford V8 4.6L and 5.4L SOHC engines. This set is sized at 0.5mm undersize, making it the correct choice for engines with a reground crankshaft at that specification. The set includes thrust washers and consists of 5 pairs of main bearing shells.

King's XP-Series was engineered specifically for high-load, long-duration racing and performance applications that use forged steel aftermarket crankshafts. The XP designation indicates a tri-metal copper-lead construction featuring a nickel barrier layer and a proprietary pMax Black™ performance overlay — a nano-scaled hardened surface that is 24% harder than conventional tri-metal race bearings, delivering superior fatigue resistance and load capacity.

Key Features:

• pMax Black™ Overlay — Proprietary hardening process creates a fatigue-resistant black shield for extreme durability under high-load conditions
• Tri-Metal Copper-Lead Construction — Enhanced intermediate layer with nickel barrier and SecureBond adhesion for superior stability between layers
• Bull's Eye Tolerance™ Technology — Wall thickness held to an industry-leading ±0.0001" tolerance for consistent clearance shell-to-shell, reducing the need for selective fitting
• Narrowed Design — Bearings are narrowed to accommodate large-radius crankshaft fillets common on performance and aftermarket cranks
• Enlarged, Chamfered Oil Holes — Half-groove design on mains preserves lower shell load capacity while promoting reliable oil delivery
• 15–30% Greater Load Capacity — Outperforms traditional tri-metal bearings under sustained high-RPM and high-load conditions
• Includes Thrust Washers — Complete set for a full main bearing service
• Size: 0.5mm Undersize — For use with crankshafts ground 0.5mm (approximately 0.020") undersize

Suited for circle track, off-road, off-shore, and other race disciplines requiring steel crankshafts and high-load endurance. King Engine Bearings has been a trusted name in precision engine bearings since 1960, supplying the aviation and motorsports industries worldwide.