King CR6640XP STDX connecting rod bearings for BMW M20, M50, M52 and M54 engines with standard crankshaft. The STDX version gives increased oil clearance compared to the STD version and is often used in performance and motorsport engines where higher load, higher oil temperatures or greater thermal expansion place greater demands on the bearings. STDX typically corresponds to approximately 0.001" / 0.025 millimetres extra oil clearance compared to standard size.
King XP Series is developed for high-performance engines and motorsport, where ordinary standard bearings are not always sufficient. The bearings are built as trimetal bearings with steel backing, copper/lead bearing material and King’s pMaxBlack surface, providing high load capacity, improved wear resistance and a stable oil film at high RPM and load. The series is often used in turbocharged, supercharged and motorsport engines with forged components.
The increased oil clearance in the STDX version can be an advantage in engines with high power, high oil temperature or where a larger safety margin in the lubrication system is desired. Correct bearing clearance should always be verified by measurement during engine assembly.
CR6640XP STDX fits a wide range of BMW straight-six engines and is suitable for rebuilds, tuning, trackday and motorsport where reliability and high load capacity are essential. The XP Series is developed for demanding applications with prolonged high load and high RPM.
Specifications:
Type: King XP connecting rod bearing set
Series: XP Series / pMaxBlack
Material: Trimetal copper/lead
Crankshaft: Standard size (STD)
Oil clearance: Approximately 0.001” / 0.025 millimetres extra oil clearance
Bearing type: Upper and lower connecting rod bearings
Contents: 12 bearing halves (6 complete connecting rod bearings)
King Engine Bearings part number: CR6640XP STDX
Fits engine code:
M20B20 / M20B23 / M20B25 / M20B27 / M50B20 / M50B25 / M52B20 / M52B25 / M52B28 / M52TUB25 / M52TUB28 / M54B22 / M54B25 / M54B30
