King Engine Bearings MB5537AM0.25 AM-Series Crankshaft Main Bearing Set Undersize - 0.25mm

The King Engine Bearings MB5537AM0.25 is an AM-Series crankshaft main bearing set designed for Mazda BPD and Z5DE engines found in the Mazda 323. This set includes 5 main bearings and features a full-groove design to ensure consistent oil distribution around the full circumference of the crankshaft journal.

Material & Construction:

• Bi-Metal Aluminum (AM-Series) construction using standard aluminum-based material equivalent to SAE-783
• Engineered for low and medium load street and marine applications
• Full-groove design supports continuous lubrication across all journal positions

King Bull's Eye Tolerance™ Technology:

• Combines highly accurate CNC machining with computerized wall thickness monitoring
• Real-time process adjustment ensures every bearing meets tight dimensional tolerances
• Overplating process provides added surface protection and conformability

Specifications:

• Series: AM-Series (Bi-Metal Aluminum)
• Material: Aluminum alloy, SAE-783 equivalent
• Size: 0.25mm Undersize
• Groove Type: Full Groove
• Engine Codes: BPD, Z5DE (1.5L, 1.6L, 1.8L)

King Engine Bearings has been a trusted name in precision engine bearings since 1960, supplying the automotive, motorsport, and aviation industries with high-quality components. The AM-Series is recommended for stock replacement and street performance rebuilds where proven bi-metal aluminum construction is required.