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ACL connecting-rod bearing set — manufacturer catalog product photo
ACL engine bearing-shell profile drawing — shell shape and oil-hole layout
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ACL Acura B17A1/B18A1/B18B1 0.25mm Overzized High Performance Rod Bearing Set

ACL
ACL4B1946H-.25
9315726277577
Bearings
Out of stock
$ 104.85

ACL 4B1946H-.25 is a connecting-rod bearing set for the cataloged Honda A18A, A20A1, A20A2, A20A3 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

ACL’s 2023 guide distinguishes B18A/B20A SOHC rod applications in the 4B1946 family from B20A/B21A/B21A1 DOHC applications in 4B1936. B18C1/B18C2/B18C5/B18C7 VTEC applications instead use 4B1925. The listed B16A, B17A1, B18A1, B18B1, B18B2, B20B and B20Z applications pair 4B1946 rods with 5M1959 mains; the listed B18A/B20A SOHC applications use 5M1957 mains. Verify the exact engine and valve configuration.

Manufacturer / Engine Honda — A18A
Manufacturer / Engine Honda — A20A1
Manufacturer / Engine Honda — A20A2
Manufacturer / Engine Honda — A20A3
Manufacturer / Engine Honda — A20A4
Manufacturer / Engine Honda — B16A1
Manufacturer / Engine Honda — B16A2
Manufacturer / Engine Honda — B16A3
Manufacturer / Engine Honda — B16A4
Manufacturer / Engine Honda — B16A6
Manufacturer / Engine Honda — B17A1
Manufacturer / Engine Honda — B18A
Manufacturer / Engine Honda — B18A1
Manufacturer / Engine Honda — B18B1
Manufacturer / Engine Honda — B18B2
Manufacturer / Engine Honda — B20A3
Manufacturer / Engine Honda — B20A4
Manufacturer / Engine Honda — B20B3
Manufacturer / Engine Honda — B20B4
Manufacturer / Engine Honda — B20B8
Manufacturer / Engine Honda — B20Z2
Manufacturer / Engine Honda — ES
Manufacturer / Engine Honda — ET
Manufacturer / Engine Honda — F18B
Manufacturer / Engine Honda — F20B3
Manufacturer / Engine Honda — F20B5
Manufacturer / Engine Honda — F20B6

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

Brand ACL
Manufacturer Part Number 4B1946H-.25
Component Connecting-Rod Bearing Set
Size Selection .25 mm journal repair-size designation. Confirm the required undersize journal diameter and assembled clearance with the engine builder.
Catalog Family ACL Race Series
Half Type Identical halves
Catalog Size Options STD, .025, .25

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 builder’s 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 4B1946H-.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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