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

King Engine Bearings XP-Series tri-metal main bearings are high-performance crankshaft main bearings. They are built for engines that see extreme loads, high RPM and long-duration racing. The XP-Series was developed for performance applications that use forged steel aftermarket crankshafts and put heavy, sustained loads on the bearings.

Key Features:

• Enhanced tri-metal construction: a copper-lead layer with a nickel barrier and a lead/tin/copper overlay, bonded to a steel backing.
• Hard overlay: King's pMax Black tri-metal structure is rated as 24% harder than conventional tri-metal race bearings.
• Secure layer bonding: an adhesion process that keeps the layers stable and durable under load.
• Bull's Eye tolerance: very tight wall-thickness control, with shells matched to 0.0001 in. for consistent clearances.
• Improved oiling: enlarged, chamfered oil holes help oil flow into the bearing.
• Optimized geometry: medium eccentricity helps distribute load and improve oiling.
• Crankshaft compatibility: bearings are narrowed for large-radius crankshafts.

These main bearings are available in a range of undersize options for engines with reground crankshafts. They suit circle track, off-road, off-shore and other high-load racing and performance builds. Also known as crankshaft main bearing sets or performance engine bearings.