King Engine Bearings CR4596XP0.25 XP Series Tri-Metal Connecting Rod Bearing Set 0.25mm Undersize

The King Engine Bearings CR4596XP0.25 is a high-performance connecting rod bearing set from King's XP Racing Series, purpose-built for the BMW S14B20, S14B23, and S14B25 four-cylinder engines. This 0.25mm undersize set is engineered to handle the extreme loads and sustained high-RPM demands of both track and performance street applications.

At the core of this bearing set is King's proprietary pMax Black™ tri-metal construction—a unique layered metallurgical structure that delivers superior load capacity and fatigue resistance compared to conventional race bearings. The intermediate layer features an elevated 4.5% tin content, making it significantly harder and capable of withstanding loads up to 17,000 psi, while the overlay's nano-scaled hardening process results in an overall 24% increase in load capacity (10,200 psi) versus standard tri-metal designs.

Key Features:

• pMax Black™ Tri-Metal Structure – 24% greater load capacity than conventional tri-metal race bearings, with a proprietary nano-scaled hardening process that creates a fatigue-resistant overlay
• Bull's Eye Tolerance™ – Industry-leading wall thickness precision with all shells matched to 0.0001", ensuring perfect oil clearance in every set
• U-Groove™ Design – 90° oil groove geometry expands the effective bearing surface area, increasing load capacity while maintaining full oil flow
• ElliptiX™ Oiling – Hybrid oil slot/oil hole design improves oil ingress to the bearing surface without compromising load-carrying area
• RadiaLock™ Crush Height – Application-optimized crush height engineered via elasto-hydrodynamic analysis, reducing the risk of bearing spin under extreme loading
• EccentriX™ Eccentricity – Optimized eccentricity profile ensures stable hydrodynamic lubrication and an improved oil wedge at high RPM
• SecureBond™ Adhesion – Micro-etch surface preparation strengthens tri-metal layer adhesion, reducing the risk of delamination under extreme load or metal-to-metal contact
• 0.25mm undersize for use with reground crankshafts
• Compatible with forged steel aftermarket crankshafts

The XP series was developed specifically for performance applications producing high loads for extended periods, making it an ideal choice for circle track, drag racing, and high-output BMW S14-based builds. Cross-reference OEM part numbers include: 1310515, 1310517, 1310518, 1310519. Compatible ACL reference: 4B1568H. GLYCO reference: 71-3652.