King Engine Bearings MB5209XP STDX XP-Series Tri-Metal Main Bearing Set Mitsubishi 4G63 4G64 EVO I-IV

The King Engine Bearings MB5209XP STDX is a complete XP-Series crankshaft main bearing set engineered for the Mitsubishi 4G63, 4G63T, and 4G64 engines found in 1992–1997 applications including the 7-bolt DSM platform and EVO I–IV. The STDX suffix indicates +0.001" (0.026mm) extra oil clearance over standard, making this set ideal for high-performance builds requiring increased lubrication flow to the crankshaft journals.

The XP-Series (Xtreme Performance) is King's race-focused bearing line built on advanced metallurgical and geometric technologies. These bearings feature pMax Black™, a tri-metal copper-lead construction with a nickel barrier layer and a lead/tin/copper Babbitt overlay electroplated over a steel backing shell. This multi-layer structure delivers outstanding load capacity and fatigue resistance under sustained high-RPM and high-boost conditions. The pMax Black overlay is 24% harder than conventional tri-metal race bearing overlays while still maintaining the conformability and embedability needed to protect steel crankshafts.

Key Features:

• pMax Black™ Tri-Metal Construction: Copper-lead intermediate layer with nickel barrier and hardened lead/tin/copper Babbitt overlay for extreme load capacity
• STDX Extra Clearance: +0.001" (0.026mm) over standard oil clearance — optimized for high-performance and forced-induction applications
• Bull's Eye Tolerance™: Industry-leading wall thickness control with all shells matched to ±0.0001", ensuring shell-to-shell consistency and precise oil clearance
• Narrowed Bearing Design: Mains are narrowed to clear large-radius aftermarket crankshaft fillets
• Enlarged, Chamfered Oil Holes: Improved oil delivery with 1/2 groove configuration on main bearings for uncompromised lower shell load capacity
• SecureBond Adhesion: Superior bonding between top and intermediate layers for enhanced stability under extreme loads
• Flanged Main Design: Includes flanged thrust bearing for correct fitment on the 1992–1997 4G63/4G64 block
• Sold as a complete engine set

King XP bearings are specifically designed for high-load, long-duration racing applications including circle track, off-road, and off-shore racing — and are the go-to choice for serious 4G63 builds running forged steel aftermarket crankshafts. The STDX extra-clearance sizing is commonly used in turbocharged DSM and EVO engines running elevated oil temperatures or higher-viscosity race oils.

Part Number Suffix Guide:

• MB — Main Bearing set
• XP — Xtreme Performance Tri-Metal (pMax Black) construction
• STD — Standard journal size (use with standard, unturned crankshaft)
• X — Extra clearance (+0.001" / 0.026mm over STD)