ACL 4B1925HX-STD Race Rod Bearing Set STD +0.001" Honda B18C1 B18C5 Integra ITR

Vehicle Fitment

• 1994-2001 Acura Integra GS-R DC2/DB8 (B18C1, 1.8L DOHC 16v VTEC, 170 hp - USDM)
• 1997-2001 Acura Integra Type R DC2 (B18C5, 1.8L DOHC 16v VTEC, 195 hp - USDM/CDM)
• 1995-2001 Honda Integra Type R DC2/DB8 (JDM B18C Spec R / B18C3, 1.8L DOHC 16v VTEC, 200 hp)
• 1994-2001 Honda Integra VTi-R (B18C2, 1.8L DOHC 16v VTEC - Australia/New Zealand)
• 1999-2001 Honda Integra Type R (B18C7, 1.8L DOHC 16v VTEC - Australia)

Fitment Notes

• The HX designation indicates extra oil clearance: the bearing wall is approximately 0.013mm thinner per shell compared to the standard 4B1925H-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 B18C 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 4B1925H-STD. For reground crankshafts, use the appropriate oversize H set: 4B1925H-.025 (+0.025mm) or 4B1925H-.25 (+0.25mm).
• 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, VTEC demands of built B18C applications in both naturally aspirated and forced-induction configurations.
• 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 B18C builds operating above factory 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 B18C 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: 4B1925HX-STD
• Product Line: ACL Race Series
• Application: Connecting Rod Bearings
• Engine Compatibility: Honda/Acura B18C1, B18C2, B18C3 (JDM), B18C5, B18C7 - 1.8L DOHC 16v VTEC Inline-4 (1797cc)
• Crankshaft Size: Standard (STD - Unground)
• Oil Clearance Designation: HX - Extra +0.025mm (+0.001") clearance vs. H-STD
• Shaft (Crankpin) Diameter: 44.976-45.000mm (1.7707-1.7717 in)
• Tunnel (Housing Bore): 48.000-48.024mm (1.8898-1.8907 in)
• Maximum Wall Thickness at Crown: approx. 1.489mm (0.0586 in)
• Maximum Overall Length: 17.5mm (0.689 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 4B1925HX-STD connecting rod bearing set is the extra-clearance performance option for the Honda/Acura B18C VTEC inline-4 engine family - the 1.8L DOHC 16v VTEC engine powering the Acura Integra GS-R (B18C1), Acura Integra Type R (B18C5), Honda Integra Type R DC2 (JDM), and related regional variants. Sharing the same standard crankpin journal diameter as the 4B1925H-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. This increased clearance supports a thicker hydrodynamic oil film - a meaningful advantage in high-RPM naturally aspirated builds or boosted B18C applications where a more liberal oil clearance specification is preferred.

Built on ACL's Race Series tri-metal platform, these bearings deliver superior fatigue resistance, bearing retention, and oil film stability compared to OEM Honda shells. A popular choice for B18C builders who prefer a more open clearance specification at stock journal size, particularly when running lightweight racing oils or building for sustained high-RPM operation. Always confirm actual running clearance at assembly. Sold as a complete set of 8 shells for one engine.