King Engine Bearings MB 511XP STDX XP-Series Main Bearing Set Alfa Romeo AR01608/34

The King Engine Bearings MB 511XP STDX is a professional-grade, race-proven main bearing set designed for Alfa Romeo engines with OEM reference AR01608/34. Part of King's renowned XP-Series (Xtreme Performance) line, this set is engineered to handle the extreme demands of high-performance and racing applications.

XP-Series Tri-Metal Construction:

• Tri-metal layered design featuring a copper-lead construction with a nickel plate barrier and lead/tin/copper Babbitt overlay over a steel backing
• Advanced adhesion process delivers superior stability and long-term durability under high loads
• Narrowed bearing profile accommodates large-radius crankshafts common in performance builds
• Enlarged, chamfered oil holes with full, 3/4 in., or 1/2 in. grooving for improved oil flow and lubrication

Precision Manufacturing:

• Wall thickness tolerances held to an exceptional +/- 0.0001 in. — tighter than industry standard
• STDX sizing — standard crankshaft journal diameter with an additional 0.001 in. extra oil clearance for improved lubrication under racing conditions
• pMax Black tri-metal material for superior load capacity
• Radialock design for optimal crush height and secure seating in the bearing housing

Key Specifications:

• Bearing Type: Main Bearing Set (MB)
• Series: XP (Xtreme Performance / Tri-metal)
• Size: STDX (Standard + 0.001 in. extra oil clearance)
• OEM Cross-Reference: Alfa Romeo AR01608/34
• Flange: Standard

King Engine Bearings has been manufacturing precision engine bearings since 1960, and the XP-Series represents their top-tier race offering. These bearings are trusted by circle track, off-road, and offshore racing teams requiring maximum reliability under sustained high-load conditions.