Reinforced exhaust valves Nissan Bluebird SR20VE

Nissan engines covered

The SR20VE is the NEO VVL variable lift version of Nissan's 2 litre SR20 four, with 16 valves and twin overhead camshafts. This page covers its first generation, known as P11, with 6 mm valve stems, fitted in particular to the Bluebird U14 from 1997.

Its 8 exhaust valves, two per cylinder, carry the original part number 13202-1N500. Switching to high lift at high rpm exposes them for long periods to very hot burnt gases.

SUPERTECH reinforced exhaust valves

An exhaust valve head reaches 760 to 870 °C on a naturally aspirated engine and goes past 1,000 °C with forced induction; this is the temperature of the metal. About 75 % of that heat passes through the seat and 20 % through the guide. An EV8 family steel holds 550 MPa at 600 °C but only 300 MPa at 800 °C: the head overheats, distorts and eventually bears badly on its seat.

SUPERTECH makes these valves in Inconel, a nickel-based superalloy that keeps 860 MPa at 730 °C and 554 MPa at 815 °C, about 85 % more than EV8 steel near 800 °C.

The +2 mm version takes the head from 29.15 to 31.15 mm, with stem and length unchanged: each millimetre of head adds 10 to 12 cfm of flow and burnt gases leave faster. The 8 exhaust seats are then machined to that diameter.

Exhaust valve technical specifications

NEVI-1004-VE: 29.15 mm head (standard); NEVI-1007-VE: 31.15 mm head (+2 mm); 5.97 mm stem and 100.5 mm length for both.

Valve fitting

On reassembly, the 6 mm collets must seat properly in the groove of the new valves; the KPR-6N-6-ST collets are intended for this engine.

At 29.15 mm, recutting the seats is enough; at 31.15 mm, the 8 exhaust seats are machined.

Fit all 8 valves at the same size and install new exhaust valve stem seals, such as VS-N6E-8.

Technical guide

Our brand

SUPERTECH Performance has been designing racing valves and valvetrain parts in California for more than thirty years. For the SR20VE with 6 mm stems it offers two Inconel exhaust valves, at standard size and +2 mm.

How to choose

The two versions differ by size:

When reinforced valves become necessary

• Adding a turbo or supercharger (Inconel version recommended)
• Camshafts with more lift
• Track days at high rpm
• Cylinder head rebuild with burnt or distorted exhaust valves

Vehicle compatibility

OEM part number (exhaust valve): 13202-1N500

Don't forget the inlet valves

With the SR20VE head off, replace the inlet valves and the valve stem seals as well.