SUPERTECH bronze inlet valve guides Nissan RB20 RB25 RB26 VQ37VHR

Nissan and Infiniti engines concerned

This kit covers the inlet side of Nissan's 24-valve RB six-cylinder family, the 2.0 litre RB20DE and RB20DET, the 2.5 litre RB25DE, RB25DEH and RB25DET and the twin-turbo RB26DETT of the Skyline GT-R, as well as the 3.7 litre VQ37VHR V6 of the Nissan 370Z and Infiniti G37, Q50 or Q60.

Each of these engines has 12 inlet valves, hence a kit of 12 guides. Nissan lists the inlet guide as 13212-58S60 on the RB20 and RB25 and 13212-05U10 on the RB26DETT of the R33 and R34; on the VQ37VHR, the inlet valve stem measures 5.965 to 5.980 mm.

SUPERTECH manganese bronze inlet valve guides

The inlet guide centres the stem above the seat, conducts part of the heat it picks up into the cylinder head and keeps the stem seal in place. When it goes oval, the valve knocks in its bore, lands askew on the seat and lets oil run down the stem, with blue smoke, oil burnt and compression dropping, all the faster on a turbocharged engine.

SUPERTECH makes these guides from precisely machined manganese bronze; according to the brand, this bronze conducts heat clearly better than a stock sintered guide. The 12 guides in the kit serve every inlet valve of one engine and are generally fitted together with reinforced valves.

Valve guide technical specifications

Valve guide installation

Technical guide

SUPERTECH also offers reinforced inlet valves for the RB20, RB25 and RB26DETT:

Our brand

Based in San Jose, SUPERTECH has been building racing valvetrain parts for more than thirty years, calculated by finite element analysis and inspected by ultrasound, X-ray and laser before shipping.

Standard or oversize?

This guide comes in standard size, 10.03 mm outside diameter, and SUPERTECH lists a 0.001" (0.0254 mm) oversize version for the RB26DETT.

Manganese bronze

Made of copper and zinc strengthened with iron, aluminium and manganese, this bronze offers high mechanical strength, wears little and copes well with corrosion; it is commonly found in bushes and guide bearings that take heavy loads.

When valve guides must be replaced

• Oil running down the inlet valve stems
• Reinforced valves for an already worn cylinder head
• Engine prepared for track, drift or rally
• Full overhaul of the cylinder head and valvetrain

Vehicle compatibility

OEM part number (valve guide): 13212-58S60 (RB20, RB25) ; 13212-05U10 (RB26DETT)

Remember the exhaust guides and valve stem seals

On reassembly, new valve stem seals go in with the guides. For these engines we offer: