ACL 5M1573H-.025 Race Series Main Bearing Set for 2008+ BMW N63/S63 4.4 L V8

Vehicle Fitment

• 2008-present BMW models equipped with the N63B44 4.4 L twin-turbo V8
• 2011-present BMW M-model S63B44 4.4 L twin-turbo V8

Features

• Race Series high-performance main bearing set
• +0.025 mm oversize to accommodate performance-machined crank journals
• Tri-metal alloy construction for superior fatigue resistance
• Hardened steel backing for improved bearing shell stability
• 3/4 oil-groove design on main shells for optimal oil flow
• Increased crush tolerance to enhance bearing retention under high load
• Optimised eccentricity for consistent oil film formation under high RPM
• Enlarged ID chamfers to clear large fillet radii on performance crankshafts

Specifications

• Part Number: 5M1573H-.025
• Oversize size: +0.025 mm
• Bearing category: full main bearing set for BMW 4.4 L twin-turbo V8 (N63/S63)

Included Components

• 1x Complete main bearing set (upper + lower shells for engine main journals)

Product Description

The ACL 5M1573H-.025 Race Series main bearing set is engineered specifically for BMW's 4.4 L twin-turbo V8 platforms (N63B44 / S63B44). With a +0.025 mm oversize specification, this bearing set is ideal when the crankshaft journals have been machined or ground for high-performance use. The tri-metal alloy construction combined with hardened steel backing ensures robust durability and stability under aggressive engine conditions.

Designed for performance and high RPM applications, the 3/4 oil-groove design and optimised eccentricity help maintain a consistent oil film and effective lubrication under demanding circumstances. Enlarged chamfers ensure compatibility with performance crankshafts with large fillet radii, making the set suited for aftermarket builds, rebuilds, and motorsport usage.

This bearing set is compatible with BMW models equipped with the N63 or S63 4.4 L twin-turbo V8 engines from 2008 onward. Always verify crank journal diameter, bearing housing size, and surface condition before installation to ensure correct oil clearance and optimal performance.