Reinforced inlet valves NISSAN Patrol TB48DE

NISSAN engines covered

The TB48DE is Nissan's 4.8 litre 24-valve petrol inline six with twin overhead camshafts, from 245 to 284 hp depending on version. It powers the Patrol GR Y61, estate and pick-up, from 2000, then the Patrol Y62.

The engine has 12 Nissan 13201-VC200 inlet valves, held by 13210-D4200 collets under 13209-D4200 retainers. A supercharger, sharper camshafts or hard loaded off-road use push them well beyond stock duty.

SUPERTECH reinforced inlet valves

Each inlet valve of the six opens to let fresh air in, drops back onto its seat at every closing and slides in its guide, thousands of times per minute. It runs between 400 and 550 °C, where the original chrome-silicon steel falls from 500 MPa at 500 °C to 250 MPa at 600 °C, 50 % of its strength lost.

SUPERTECH makes this valve from a racing stainless steel of the EV8 family, which keeps 650 MPa at 500 °C and 550 MPa at 600 °C, 30 % and then 120 % more than the original steel, black nitrided for a harder, smoother stem in the guide.

SUPERTECH supplies it in +1.5 mm oversize: 40.0 mm flat head, 6.97 mm stem and 100.10 mm length. The wider head opens a larger passage at the seat, the cylinder fills better and the engine gains power, provided the inlet seats are cut to this size.

Inlet valve technical specification

NIVN-4070F-12: flat face head, undercut stem under the head, 32° back cut and swirl polish.

Fitting details

The +1.5 mm size needs inlet seats cut to 40.0 mm, workshop work to plan with the cylinder head rebuild.

Technical guide

The brand offered

SUPERTECH works out of San Jose, California, and has supplied valvetrain parts for racing engines for more than 30 years: valves, springs, retainers and guides. Each part number starts from a specific cylinder head, goes through ultrasound, X-ray and laser checks, then is proven with engine builders, from drag strip to circuit.

When reinforced valves become necessary

• Higher-lift camshafts or stiffer springs
• Raised rev limit
• Turbo or supercharger fitted
• Cylinder head rebuilt for circuit, hill climb or rally
• Original valves marked, worn or already reground

Compatible vehicles

OEM part number (inlet valve): 13201-VC200

Related products

For a rebuilt TB48DE cylinder head, the reinforced exhaust valves are available here: