ACL 4B1925H-.025 Race Rod Bearing Set +0.025mm Honda B18C1 B18C5 Integra GSR 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 .025 suffix designates this as the +0.025mm oversize bearing set - intended for use when the crankshaft rod journals have been ground 0.025mm undersize during a rebuild. The thicker wall restores correct running oil clearance on a lightly reground crankshaft.
• Do NOT use on a stock, unground crankshaft. For standard journal diameter, use 4B1925H-STD. For crankpins ground 0.25mm undersize, use 4B1925H-.25.
• Always measure crankshaft rod journal diameter with a micrometer before selecting bearing size. Confirm actual clearance with Plastigage or a dial bore gauge after assembly.
• 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.
• 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: 4B1925H-.025
• 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: +0.025mm Oversize (for crankpins ground 0.025mm undersize)
• 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: 1.502mm (0.0591 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 - +0.025mm Oversize

Product Description

The ACL Race Series 4B1925H-.025 connecting rod bearing set is the +0.025mm oversize 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), and the legendary Honda Integra Type R DC2 (JDM B18C/B18C3), among other regional variants. This oversize set is selected when the crankshaft rod journals have been lightly reground 0.025mm undersize to clean up surface condition or restore proper geometry during a rebuild, restoring correct oil clearance on the reground crank.

The B18C family - particularly the B18C5 and JDM Type R spec - is one of the most frequently rebuilt high-performance Honda four-cylinder engines, known for its high specific output and willingness to rev. ACL Race Series bearings deliver superior fatigue resistance, oil film stability, and bearing retention compared to OEM Honda shells, making them a standard upgrade in any serious B18C rebuild. Always verify crankshaft journal diameter with precision measurement and confirm clearances at assembly before final torque. Sold as a complete set of 8 shells for one engine.