King Engine Bearings MB5286XP XP Series Tri-Metal Performance Main Bearing Set

The King Engine Bearings MB5286XP is an XP Series performance crankshaft main bearing set engineered for Toyota 1UZ-FE, 2UZ-FE, and 3UZ-FE V8 engines. Designed specifically for high-load, long-duration racing applications that utilize forged steel crankshafts, this set delivers the strength and precision demanded by serious race engine builders. The set includes 5 pairs of main bearing shells.

pMaxBlack™ Tri-Metal Construction

The MB5286XP features King's proprietary pMaxBlack™ tri-metal bearing structure, engineered to outperform conventional tri-metal race bearings in both load capacity and surface durability. The enhanced intermediate layer uses increased tin content, delivering a hardness of 115 HV and a load carrying capacity of 17,000 psi. The overlay employs a nano-scaled hardening process with elevated copper content for superior resistance to surface fatigue under extreme loads.

XP Series Features:

• pMaxBlack™ Overlay: 0.0005" metallurgically enhanced hardened overlay withstands greater loads and resists surface fatigue better than conventional overlays
• SecureBond Adhesion: Proprietary bonding process ensures superior stability between the top and intermediate bearing layers
• 15%–30% Greater Load Capacity compared to traditional bearings
• Bull’s Eye Tolerance: Tightest wall thickness tolerances in the industry — all shells matched to 0.0001" for shell-to-shell consistency
• Half-Grooved Mains: Upper shells are half-grooved to maintain uncompromised load capacity in the lower shell
• Enlarged, Chamfered Oil Holes: Improved oiling geometry with a 90° oil groove shape maintains oil flow and increases bearing load capacity
• Medium Eccentricity: Optimized via elasto-hydrodynamic analysis for ideal load distribution and enhanced lubrication
• Narrowed Design: Accommodates large-radius crankshaft fillets on both mains and rod journals
• Optimized Crush Height: Precision crush height engineered specifically for each performance bearing application

Ideal Applications:

• Circle track, drag racing, off-road, and off-shore racing
• High-load, extended-duration performance builds using steel crankshafts
• Performance engine rebuilds requiring tight tolerances and maximum reliability

King Engine Bearings has been manufacturing precision engine bearings since 1960, and the XP Series represents their top-tier solution for race and high-performance applications. Available in standard and multiple oversize options to accommodate stock and machined crankshafts.