King Engine Bearings MB5442XP0.5 XP-Series High Performance Main Bearing Set +0.50mm

The King Engine Bearings MB5442XP0.5 is a high-performance XP-Series main bearing set sized at +0.50mm oversize, designed for the Ford/Mazda L3 and L3-VDT MZR DISI Duratec engines found in the 2007–2009 Mazdaspeed 3. Engineered for demanding performance applications, these bearings are built to handle elevated loads and high RPM conditions far beyond the capability of standard OEM bearings.

King's XP-Series utilizes pMaxBlack™ tri-metal construction — a uniquely hardened layered structure with a copper-lead intermediate, nickel barrier, and lead/tin/copper Babbitt overlay over a steel backing. This process results in a bearing that is 24% harder than conventional tri-metal race bearings, offering superior fatigue resistance and load capacity up to 17,000 psi in the intermediate layer.

Key Features:

• pMaxBlack™ Tri-Metal Construction — 24% harder than conventional tri-metal bearings for maximum durability under race conditions
• Bull's Eye Tolerance — Wall thickness held to an industry-leading ±0.0001" for precise, consistent oil clearance in every set
• Narrowed Design — Bearings are narrowed to accommodate large-radius crankshaft fillets common in performance and modified engines
• Enlarged, Chamfered Oil Holes — Improves oil delivery and circulation for better lubrication at high RPM
• Medium Eccentricity Profile — Optimizes load distribution across the bearing surface for improved durability
• +0.50mm Oversize — Designed for use with crankshafts that have been reground 0.50mm undersize
• 12-Month Manufacturer Warranty

King Engine Bearings has been a trusted name in precision engine bearings since 1960, supplying high-quality components for automotive, marine, aviation, and motorsport applications worldwide. The XP-Series is the choice of professional engine builders who demand consistent, repeatable results in high-load, long-duration racing environments.