SUPERTECH bronze exhaust valve guides Nissan RB20 RB25 VQ37VHR

Nissan and Infiniti engines concerned

These guides go on the exhaust side of the Nissan RB20DE, RB20DET, RB25DE, RB25DEH and RB25DET inline sixes of the Skyline, Laurel, Cefiro and Stagea, and of the VQ37VHR V6 of the Nissan 370Z, Fuga and Skyline V36 and the Infiniti models of the same generation.

The 12 exhaust valves of these engines slide in pressed-in guides: Nissan 13213-58S60 for the RB20 and RB25, 13213-31U60 for the VQ37VHR, for which Nissan gives a finished bore of 6.000 to 6.018 mm and a standard outside diameter of 10.023 to 10.034 mm. The RB26DETT takes different exhaust guides.

SUPERTECH manganese bronze exhaust valve guides

At the exhaust, the guide keeps the stem aligned with the seat, passes the very high heat it builds up on to the head and forms the base of the stem seal. When worn out, it allows play: the valve hammers, closes poorly, oil seeps along the stem, and blue smoke, oil consumption and loss of compression appear. Published measurements show about a fifth of the valve's heat leaving through the guide.

Precision machined by SUPERTECH from manganese bronze, these guides transfer heat far better than original sintered guides, the brand says. The kit groups the 12 exhaust guides of one engine and is most often fitted with reinforced valves.

Valve guide technical specifications

Valve guide installation

Technical guide

SUPERTECH reinforced exhaust valves are available for the RB20 and the RB25DET:

Our brand

Born in San Jose, Silicon Valley, SUPERTECH has made its name over thirty years with racing valves, springs, titanium retainers and guides, developed via simulation and testing.

Manganese bronze

Manganese bronze combines copper and zinc with small amounts of manganese, iron and aluminium. The mix gives it toughness, slow wear and good corrosion resistance, qualities much sought after for bushes and guiding elements under heavy load.

When valve guides must be replaced

• Blue smoke after the engine has stood for a long time
• Reinforced valves going into a tired head
• Cylinder head reconditioned for competition
• Complete valvetrain refurbishment

Vehicle compatibility

OEM part number (valve guide): 13213-58S60 (RB20, RB25) ; 13213-31U60 (VQ37VHR)

Remember the inlet guides and valve stem seals

When changing the guides, plan for new stem seals. Here is our range for these engines: