ACL 4B1946HX-STD Race Rod Bearing Set STD +0.001" Honda B16A B18A B18B B20B

Vehicle Fitment

• 1989-2001 Honda Civic / CRX / Del Sol - B16A, B16A2, B16A3 variants (1.6L DOHC 16v VTEC)
• 1992-1993 Acura Integra GS-R (B17A1, 1.7L DOHC 16v VTEC)
• 1990-1993 Acura Integra GS/LS/RS (B18A1, 1.8L DOHC non-VTEC)
• 1994-2001 Acura Integra GS/LS/RS (B18B1/B18B2, 1.8L DOHC non-VTEC)
• 1997-2001 Honda CR-V (B20B / B20Z, 2.0L DOHC non-VTEC)
• Various JDM Honda Accord, Odyssey, Torneo - F18B, F20B (1.8L/2.0L SOHC VTEC)
• Honda B20A SOHC variants (1.958L SOHC)

Fitment Notes

• The HX designation indicates extra oil clearance: the bearing wall is approximately 0.013mm thinner per shell compared to the standard 4B1946H-STD set, providing approximately 0.025mm (0.001") of additional running clearance at standard crankshaft journal diameter - without any crankshaft grinding.
• Recommended for high-performance, high-RPM, or forced-induction B-series and F-series builds where slightly increased oil film thickness is desired for improved bearing protection under elevated loads and temperatures.
• For standard oil clearance at stock journal diameter, use 4B1946H-STD. For reground crankshafts, use the appropriate oversize H set: 4B1946H-.025 (+0.025mm) or 4B1946H-.25 (+0.25mm).
• Note: The B18C VTEC engines (B18C1, B18C5) use a different bearing (4B1925HX-STD). Verify your engine code before ordering.
• Always confirm actual running clearance with Plastigage or a dial bore gauge after assembly - do not rely solely on bearing size designation.
• Sold as a complete set of 8 bearing shells - sufficient for one full 4-cylinder engine build.

Features

• Tri-metal construction: copper-lead alloy lining bonded over a hardened steel backing, with a high-strength overlay plate - engineered for the high-RPM and forced-induction demands of built Honda B-series and F-series engines.
• HX extra-clearance wall thickness provides approximately 0.025mm (0.001") of additional oil clearance versus the H-STD set, increasing oil film volume between the crankpin and bearing surface for improved lubrication under extreme load.
• Hardened steel backing on all rod bearings improves structural support of the bearing lining and maintains crush under high sustained loads and temperatures.
• High-strength overlay plate with reduced thickness provides improved fatigue resistance compared to OEM-spec bearings - critical in boosted or high-revving B-series builds at elevated power levels.
• Increased bearing crush and tighter wall tolerances ensure consistent, secure seating in the connecting rod housing bore, reducing the risk of bearing spin.
• Enlarged ID chamfers on bearing edges accommodate the larger fillet radii found on performance and aftermarket Honda crankshafts.
• 3/4-groove design optimizes oil supply to the rod journal and maximizes load-carrying surface area across the bearing face.
• Elimination of flash plating on bearing backs improves heat transfer and maximizes grip between the bearing shell and the rod housing bore.
• Increased eccentricity compensates for bore distortion at high RPM and assists in the formation of a stable hydrodynamic oil film under load.

Specifications

• Part Number: 4B1946HX-STD
• Product Line: ACL Race Series
• Application: Connecting Rod Bearings
• Engine Compatibility: Honda/Acura B16A variants (1595cc); B17A1 (1678cc); B18A, B18A1, B18B1, B18B2 (1834cc); B20A SOHC, B20B, B20Z (1958/1972cc); F18B, F20B (1850/1997cc SOHC VTEC)
• Crankshaft Size: Standard (STD - Unground)
• Oil Clearance Designation: HX - Extra +0.025mm (+0.001") clearance vs. H-STD
• Shaft (Crankpin) Diameter: 44.980-45.000mm (1.7709-1.7717 in)
• Tunnel (Housing Bore): 48.000-48.024mm (1.8898-1.8907 in)
• Maximum Wall Thickness at Crown: approx. 1.491mm (0.0587 in)
• Maximum Overall Length: 19.50mm (0.768 in)
• Bearing Material: Tri-Metal Copper-Lead Alloy / Hardened Steel Backing
• Quantity: Set of 8 Shells (complete engine set)

Included Components

• 8x Race Series Connecting Rod Bearing Shells - Standard Size, Extra Oil Clearance (HX)

Product Description

The ACL Race Series 4B1946HX-STD connecting rod bearing set is the extra-clearance performance option for Honda/Acura's broad B-series and F-series inline-4 engine family - covering the B16A, B17A1, B18A1, B18B1, B20B, B20Z, and related engines found in the Civic, CRX, Del Sol, Acura Integra (non-VTEC and B17), CR-V, and various JDM platforms. Sharing the same standard crankpin journal diameter as the 4B1946H-STD, the HX variant uses a slightly thinner wall (~0.013mm per shell) to deliver approximately 0.025mm (0.001") of additional running oil clearance without any crankshaft modification.

The HX variant is a popular choice for boosted B-series builds - turbocharged B18A/B18B and B20B/B20Z engines in particular benefit from the additional oil film thickness under sustained elevated cylinder pressures. Note that the B18C VTEC engines use the separate 4B1925HX-STD set. Built on ACL's Race Series tri-metal platform, these bearings deliver superior fatigue resistance and oil film stability compared to OEM Honda shells. Always confirm actual running clearance at assembly. Sold as a complete set of 8 shells for one engine.