Reinforced inlet valves CITROËN Xsara C2 C3 C4 TU5JP4

CITROËN engines covered

The TU5JP4 is PSA's 1.6 litre (1,587 cc) four-cylinder with 16 valves, 78.5 mm bore and 82 mm stroke. At Citroën it is fitted to the Xsara, Xsara Picasso, C2, C3, C4 and Berlingo from 2000 onwards, from 109 to 116 hp depending on version.

Its cylinder head takes 8 inlet valves, two per cylinder. This engine lends itself well to tuning: sharper camshafts, higher revs or a head rebuilt for racing put heavy demands on the original valves.

SUPERTECH and CATCAMS reinforced inlet valves

Opened and closed on every cycle, the inlet valve lets fresh air through, drops back onto its seat and slides in its guide, dozens of times per second once the engine revs. It heats up to between 400 and 550 °C, where the original chrome-silicon steel goes from 500 MPa at 500 °C to 250 MPa at 600 °C: half of its strength, 50 %, is gone.

The SUPERTECH PEIVN-28603-8 is black nitride stainless steel: this hard layer protects the stem from wear in the guide. Its stem is undercut below the head, which saves weight and opens the gas path, and the back of the head is cut to ease the air towards the seat.

Both sets have a 31.3 mm head. The SUPERTECH, supplied in standard size, is 103.8 mm long; the CATCAMS 9249005M has a 6 mm stem and is 103.7 mm long.

Inlet valve technical specification

Fitting details

Before assembly, check that the collets match the groove of the chosen valves.

Technical guide

The brands offered

	Based in San Jose, California, SUPERTECH Performance has devoted more than thirty years to racing valvetrains: valves, springs, retainers and guides. Every batch is checked by ultrasound, X-ray and laser, then proven by engine builders from drag strip to circuit.
	Built in Europe around the racing camshaft, CATCAMS also offers valves, springs and retainers matched to its profiles, for rally, hillclimb and circuit engines.

How to choose

The groove is the recess cut near the end of the stem, where the collets hold the upper retainer. Both sets share the same head and differ in brand, length and finish:

When reinforced valves become necessary

• Sharper camshaft or stiffer springs
• Higher rev limit
• Turbocharger or supercharger fitted
• Cylinder head rebuilt for rallying, hillclimb or circuit
• Worn original valves or seats already reground

Compatible vehicles

Related products

For a rebuilt TU5JP4 cylinder head, the reinforced exhaust valves are on this page: