SUPERTECH bronze exhaust valve guides 7 mm stem Nissan SR20DET

The Nissan SR20DET engine concerned

The SR20DET of the Sunny GTI-R (N14) is a 2.0 litre turbo four-cylinder with 16 valves and twin overhead camshafts. For it SUPERTECH describes an exhaust guide with a 7 mm bore, paired with the brand's VS-N7E stem seal. Each head calls for eight.

The standard outside diameter is 11.03 mm for a length of 43 mm. A version oversize by 0.001 inch also exists: the set of 8 guides is ordered in either size.

SUPERTECH manganese bronze exhaust valve guides

A turbo sends scorching gas onto the exhaust valve, and the stem only cools through contact with the guide, which passes the heat back into the head. As wear sets in, play grows, the valve meets its seat off-square and a film of oil runs toward the manifold: blue smoke, oil consumption, a turbo that gets fouled.

This SUPERTECH guide is made of manganese bronze, a material whose thermal conduction, the brand states, is clearly higher than that of the sintered factory guides. It goes with exhaust valves whose stem measures 7 mm and with the VS-N7E seal, which are ordered separately. The set holds the 8 exhaust guides of one head, in standard or oversize depending on the option chosen.

Valve guide technical specifications

Valve guide installation

Technical guide

For the GTI-R exhaust side, a reinforced valve is offered:

Our brand

Based in San Jose, California, SUPERTECH equips motorsport with valve train parts: valves, guides, retainers and springs. According to the brand, each part is examined by ultrasound, X-ray and laser before it goes to the builders of racing engines.

Standard or oversize?

The standard version measures 11.03 mm outside diameter. The oversize version, marked " .001 oversize " by SUPERTECH, adds 0.001 inch, or 0.0254 mm, for a slightly wider head bore; the brand does not publish its exact diameter.

Manganese bronze

Copper, zinc, manganese, iron and aluminium make up this hard alloy, which is little affected by friction wear and by corrosion. Makers of heavily loaded bushings and guiding parts often choose it, which explains why it appears in valve guides.

When valve guides must be replaced

• Blue smoke on lift-off, oil disappearing
• Reinforced exhaust valves with a 7 mm stem in a worn head
• Sunny GTI-R pushed hard on track or rally
• Complete head overhaul

Vehicle compatibility

Important: this set targets only the SR20DET of the Sunny GTI-R, not the other versions of this engine or the naturally aspirated SR20DE.

Remember the valve stem seals

These guides go with new stem seals. For the SR20DET inlet side we offer the SUPERTECH 6 mm seals, in sets of 12: