King Engine Bearings MB 612XP0.5 XP-Series Main Bearing Set 0.50mm Undersize

The King Engine Bearings MB 612XP0.5 is a complete crankshaft main bearing set designed for the Ford Focus ST 2.5L turbocharged HYDA engine and Volvo 5-cylinder engines sharing the B52xx engine family (B5204, B5234, B5244, B5254). This set is sized at 0.50mm undersize, intended for use with reground crankshafts that have been machined 0.50mm below standard journal diameter.

Built to King's XP-Series (Xtreme Performance) tri-metal specification, these bearings feature a steel backing, copper-lead intermediate layer, nickel barrier plate, and a lead/tin/copper Babbitt overlay — a construction that delivers outstanding fatigue resistance and load capacity under high-boost, high-performance conditions.

Key Features:

• Tri-metal pMaxBlack construction — copper-lead lining with nickel barrier and hardened Babbitt overlay for superior load capacity and fatigue resistance
• 0.50mm undersize — engineered for crankshafts reground 0.50mm under standard journal diameter
• Bull's Eye Tolerance™ technology — proprietary wall thickness control held to ±0.0001 in. for consistent oil clearance shell-to-shell
• Enlarged, chamfered oil holes — optimized oil feed for improved lubrication under high-performance and forced-induction use
• Complete set — includes all main bearing shells required for one engine assembly
• Ideal for street performance, road racing, and high-boost turbo applications

The King XP-Series is the preferred choice of professional engine builders seeking a high-performance alternative to OEM main bearings. The MB 612XP0.5 is especially well-suited to rebuilt Ford ST 2.5L turbo engines and Volvo inline-5 engines where the crankshaft has been reground to 0.50mm undersize.