ACL BMW N63/S63 V8 0.25 Oversized High Performance Rod Bearing Set

ACL 8B1578H-.25 is a connecting-rod bearing set for the cataloged BMW N63B44, S63B44 engine configurations. .25 mm journal repair-size designation. Confirm the required undersize journal diameter and assembled clearance with the engine builder.

Bearing Configuration

H identifies the ACL Race Series family. Match the complete suffix to the required clearance, shell width and locating features.

Engine Application

ACLs 2023 guide specifies March 2011 onward for the 8B1578 rod-bearing application in N63B44 and S63B44 4395cc V8 engines. Confirm the engine production date and exact rod configuration; the N63/S63 engine name alone does not establish compatibility with an earlier build.

The engine-family list identifies catalog applications, not universal vehicle fitment. Confirm the exact engine version, crankshaft, rods, block and bearing location. Vehicle names and photos do not replace dimensional verification.

Specifications

Quantity and Assembly Checks

Confirm the rod-bearing set contents and shell positions against the complete manufacturer number. The photo is representative of the part family.

Measure shaft journals, housing bores and assembled oil clearance using the engine builders specification. Check oil-hole alignment, groove placement and crankshaft fillet clearance before final assembly. Catalog standard dimensions must not be treated as the finished dimensions for a different repair size. ACL specifies that abrasive pads or paper must not be used on the bearing surface to alter oil clearance.

Frequently Asked Questions

Is the year and model enough to choose this bearing? No. Match 8B1578H-.25 to the exact engine and measured build specification.

What size is this listing? .25 mm journal repair-size designation. Confirm the required undersize journal diameter and assembled clearance with the engine builder.

Can I substitute a different suffix? Compare the complete grade, size, locating features and assembled clearance before substituting any bearing.

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