Reinforced inlet valves HONDA J32A1

HONDA engines covered

The J32A1 is Honda's 3,210 cc 24-valve V6 with single overhead camshaft VTEC (SOHC), 260 hp. It powers the Inspire UA5, from 1998 to 2003.

It has 12 inlet valves, two per cylinder. A sharper camshaft, stiffer springs, a higher rev limit or forced induction ask far more of them than stock use.

SUPERTECH reinforced inlet valves

On the inlet side, each valve opens and closes dozens of times a second at high rpm, strikes its seat and slides constantly in its guide, at 400 to 550 °C. At these temperatures the chrome-silicon steel of stock valves drops from 500 MPa at 500 °C to 250 MPa at 600 °C: it loses 50 % of its strength.

These SUPERTECH valves are black nitrided: the surface becomes harder and smoother, which cuts friction and stem wear in the guide.

SUPERTECH supplies it with a 34.0 mm head, a 5.48 mm stem and a 114.7 mm length.

Inlet valve technical specification

HIVN-3234-12: dished head.

Fitting details

The number of grooves on the valve and on the collets must match: these single-groove valves are fitted with KPR-5.5-7A-ST collets, single groove, 5.5 mm, 7°.

Technical guide

The brand offered

SUPERTECH, based in San Jose, California, has designed valvetrain parts for racing engines for more than 30 years: valves, springs, retainers, guides. Each valve is drawn for a given cylinder head, checked by ultrasound, X-ray and laser, then proven with engine builders, at the drag strip as on the 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

Related products

For a rebuilt J32A1 cylinder head, the reinforced exhaust valves are available here: