King Engine Bearings MB1333XP0.25-5 XP Series Main Bearing Set Undersize - 0.25mm

The King Engine Bearings MB1333XP0.25-5 is a performance main bearing set from King's renowned XP (eXtreme Performance) series, featuring an 0.25mm undersize specification. Designed for high-performance and competition engine builds, these main bearings deliver superior reliability and durability under demanding operating conditions.

King's XP series bearings incorporate the proprietary pMax Black coating technology — a specialized polymer overlay applied to the bearing surface that dramatically reduces friction, improves wear resistance during cold starts, and provides exceptional protection during oil starvation events. The advanced tri-metal construction features a steel backing, copper-lead or aluminum alloy middle layer, and the high-performance surface coating for maximum load capacity.

Key Features:

• XP Series pMax Black Coating — advanced polymer overlay reduces friction and protects against dry starts
• 0.25mm Undersize — engineered for journals that have been machined 0.25mm undersize during engine reconditioning
• Tri-Metal Construction — steel-backed with high-strength bearing alloy for superior load-carrying capacity
• Eccentricity Design — King's proprietary eccentric geometry promotes optimal oil wedge formation and hydrodynamic lubrication
• High Crush and Conformability — precise wall thickness tolerances ensure proper seating and consistent oil clearances
• Performance Engineered — suitable for naturally aspirated, turbocharged, supercharged, and high-RPM competition engines
• OE-Quality Standards — manufactured to meet or exceed original equipment specifications

King Engine Bearings is a globally recognized manufacturer trusted by professional engine builders, racing teams, and OEM manufacturers worldwide. The MB1333XP0.25-5 is ideal for engine rebuilders seeking maximum performance and longevity in a precision-machined crankshaft main bearing application.