GSC Power Division Nissan RB26 / SR20 / VR38 Valvetrain

• Billet camshafts - S-series and R-series profiles for RB26DETT (R32/R33/R34 GT-R) and VR38DETT, including options noted as requiring head modification.
• Intake and exhaust valves - standard, +1mm and +2mm head sizes in 21-4N, 23-8N, chrome polished and super alloy specifications.
• Valve springs and titanium retainers - conical, shimless, cylindrical and high-pressure kits.
• Spring seats, keepers and stem seals - chromoly seats, keeper sets and valve stem seal sets.
• Valve guides - manganese bronze guides in standard and stopper styles.
• Lifters and tappets - DLC shim bucket tappets listed for RB26DETT applications.

Select by engine code first. RB26DETT covers the R32, R33 and R34 GT-R twin-turbo inline six; SR20DET covers turbocharged Silvia, 180SX and 200SX applications; VR38DETT covers the R35 GT-R V6. Some GSC guides and keeper sets are listed as shared across SR20DET/RB26DETT or VR38DETT/2JZ, so check the title for both codes. Valve sizes are listed as STD, +1mm or +2mm - oversize valves and certain camshaft profiles are noted as requiring seat changes or head modification, so confirm your cylinder head specification with your engine builder before ordering.

Valvetrain components require the cylinder head to be removed and, in most cases, disassembled. Valve guide replacement, seat cutting and spring installed-height checks are machine shop tasks requiring specialised tooling such as a valve spring compressor, guide drivers, a height micrometre and a spring pressure tester. Camshaft fitment requires correct valve-to-piston clearance checking and cam timing. Installation by a professional workshop or engine machinist is strongly recommended.

Do GSC camshafts suit a standard RB26 head? Some profiles are listed as direct fit, while others state "Requires Head Modification" in the title - read the listing carefully.

Are valve springs and retainers sold as matched kits? Many GSC listings are supplied as spring and titanium retainer kits, some with seats included; the title specifies what is in the set.

What do STD and +1mm mean on valves? STD is the standard head diameter and +1mm is oversize, which may require seat machining.