ACL 6B2390H-.25 Race Rod Bearing Set +0.25mm Nissan VG30 VG30DETT RB30 300ZX

Vehicle Fitment

• 1984-1996 Nissan 300ZX (Z31/Z32) - VG30E, VG30ET, VG30DE, VG30DETT (3.0L V6 NA / Twin Turbo)
• 1985-1994 Nissan Maxima - VG30E, VG30i (3.0L V6 SOHC)
• 1987-1988 Nissan 200SX - VG30ET (3.0L V6 Turbo)
• 1987-2000 Nissan Pathfinder - VG30E, VG30i, VG33E (3.0L/3.3L V6)
• 1990-1994 Nissan D21 Hardbody Pickup - VG30E, VG30i (3.0L V6)
• 1990-1992 Infiniti M30 - VG30DE (3.0L V6 DOHC)
• 1993-1997 Infiniti J30 - VG30DE (3.0L V6 DOHC)
• 1993-2002 Nissan Quest - VG30E, VG33E (3.0L/3.3L V6)
• 1997-2000 Infiniti QX4 - VG33E (3.3L V6)
• 1999-2004 Nissan Frontier - VG33E (3.3L V6)
• 2000-2004 Nissan Xterra - VG33E (3.3L V6)
• Australian Holden Commodore VL (1986-1988) - RB30E (3.0L Inline-6 SOHC)
• Various Nissan/Holden with RB30E / RB30ET / RB30S (2962cc Inline-6)

Fitment Notes

• The .25 suffix designates this as the +0.25mm oversize bearing set - for use when the crankshaft rod journals have been ground 0.25mm undersize. This is the more significant regrind step, typically required when journals have suffered deeper wear or surface damage beyond what the .025mm step can address. For standard journal diameter, use 6B2390H-STD. For crankpins ground 0.025mm undersize, use 6B2390H-.025. For 0.50mm undersize, use 6B2390H-.50.
• This single set covers the Nissan VG30 V6 family (VG30E/ET/i/DE/DET/DETT) and VG33E, as well as the RB30 inline-6 family (RB30E/ET/S) - all share identical crankpin journal dimensions despite being architecturally different engines.
• 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 12 bearing shells (6 pairs) - sufficient for one full 6-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-boost sustained loads of the VG30DETT twin-turbo and the high-RPM demands of naturally aspirated VG30DE applications.
• Hardened steel backing on all rod bearings improves structural support of the bearing lining and maintains crush under high sustained loads and temperatures in both turbocharged and naturally aspirated builds.
• High-strength overlay plate with reduced thickness provides improved fatigue resistance compared to OEM-spec bearings - critical in modified VG30DETT builds running elevated boost pressure.
• 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 Nissan VG/RB 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: 6B2390H-.25
• Product Line: ACL Race Series
• Application: Connecting Rod Bearings
• Engine Compatibility: Nissan VG30E/ET/i (2960cc V6 SOHC); VG30DE/DET/DETT (2960cc V6 DOHC); VE30DE (2960cc V6 DOHC); VG33E (3275cc V6 SOHC); RB30E/ET/S (2962cc Inline-6 SOHC)
• Crankshaft Size: +0.25mm Oversize (for crankpins ground 0.25mm undersize)
• Shaft (Crankpin) Diameter: 49.711-49.724mm (1.9571-1.9576 in)
• Tunnel (Housing Bore): 53.000-53.011mm (2.0866-2.0870 in)
• Maximum Wall Thickness at Crown: approx. 1.640mm (0.0646 in)
• Bearing Material: Tri-Metal Copper-Lead Alloy / Hardened Steel Backing
• Quantity: Set of 12 Shells (complete 6-cylinder engine set)

Included Components

• 12x Race Series Connecting Rod Bearing Shells - +0.25mm Oversize

Product Description

The ACL Race Series 6B2390H-.25 connecting rod bearing set is the +0.25mm oversize option for the broad Nissan VG30 V6 and RB30 inline-6 engine family - covering the VG30E, VG30ET, VG30DE, VG30DET, VG30DETT, VG33E, and RB30E/ET/S engines found across the 300ZX, Maxima, Pathfinder, Frontier, Xterra, and the Australian Holden Commodore VL, among others. This oversize set is selected when crankshaft rod journals have been ground 0.25mm undersize - a more significant regrind step typically required when journals have suffered deeper wear or surface damage that the finer .025mm step cannot correct.

All listed engines share identical crankpin journal dimensions, making this a single versatile set at the +0.25mm oversize across the entire VG/RB30 family. Built on ACL's Race Series tri-metal platform, these bearings deliver superior fatigue resistance and oil film stability over OEM Nissan shells - particularly important in VG30DETT twin-turbo builds where sustained boost places elevated demands on the rod bearing system. Sold as a complete set of 12 shells for one 6-cylinder engine.