King Engine Bearings MB5731XP XP Series Tri-Metal Main Bearing Set

The King Engine Bearings MB5731XP is a XP Series high-performance main bearing set engineered for Suzuki G13A, G13B, G13BA, and G13BB engines. Built for demanding performance and racing applications, the XP Series features advanced metallurgical and geometric technologies designed to handle extreme loads generated by forged steel aftermarket crankshafts during extended high-performance use.

At the core of the XP Series is pMax Black, a unique tri-metal structure that is 24% harder than conventional tri-metal race bearings. Combined with XP-specific geometric design features, pMax Black delivers the durability and load capacity required for circle track, off-road, offshore, and other high-load, long-duration racing disciplines.

King XP Series Features:

• Enhanced Tri-Metal Construction — Copper-lead base with nickel barrier and SecureBond adhesion for superior stability between layers
• 15%–30% Greater Load Capacity — Outperforms traditional bearings under sustained high-RPM conditions
• pMax Black Performance Overlay — 0.0005" metallurgically hardened overlay resists surface fatigue and withstands greater loads
• Bull's Eye Tolerance — Tightest wall tolerances in the industry; all shells matched to 0.0001"
• 1/2 Grooved Mains — Lower shell left ungrooved for uncompromised load capacity
• Improved Oiling — Enlarged, chamfered oil holes on main bearings for better lubrication flow
• Medium Eccentricity — Optimizes load distribution and promotes consistent oil film across the bearing surface
• Narrowed Design — Mains are narrowed to accommodate large-radius crankshafts
• SecureBond Adhesion — Proprietary bonding process ensures superior stability between the top and intermediate bearing layers

King Engine Bearings offers the industry's widest selection of sizes and special clearance options, making it easier to find the exact fit for your most demanding build. The MB5731XP is engineered specifically for Suzuki G13-series engines and is an ideal choice for performance street, track, and competition applications requiring superior reliability and load tolerance.