Reinforced inlet valves PEUGEOT CITROËN 106 S16 Saxo TU5J4

PEUGEOT and CITROËN engines covered

The TU5J4 is PSA's 1.6 litre, 16-valve, twin-cam four-cylinder that powers the Peugeot 106 S16, from 1996 to 2004, in 118 and 120 hp versions. Under the bonnet of the Citroën Saxo, the TU5J4 is PSA's 1.6 litre, 16-valve, twin-cam four-cylinder: it powers the 120 hp Saxo 1.6, from 1996 to 2004, and the 118 hp Saxo 1.6 VTS, from 1996 to 2003.

Its cylinder head carries 8 inlet valves, two per cylinder. Sharper camshafts, stiffer springs or a higher rev limit for competition expose them to more heat and harder seat impacts.

SUPERTECH, FERREA and CATCAMS reinforced inlet valves

The inlet valve opens the way for the fresh charge, drops back onto its seat at every closing and slides in its guide, between 400 and 550 °C. In that range, the chrome-silicon steel of standard valves goes from 500 MPa at 500 °C to 250 MPa at 600 °C, 50 % of its strength lost.

The FERREA 6000 Series and the SUPERTECH PEIVN-29368-8 are made of EV8 stainless steel, which keeps 550 MPa at 600 °C: 120 % better than chrome-silicon at that temperature. The SUPERTECH PEIVN-28065-8 is stainless steel; both SUPERTECH sets are black nitrided, which hardens the stem surface and limits wear in the guide.

The PEIVN-29368-8 and F6761*8 take the head to 29.75 and 29.8 mm, 1 mm larger, with stem and length unchanged: air flows through a wider area, the cylinder fills better and the engine gains power, once the 8 inlet seats are machined to that size.

Inlet valve technical specification

Fitting details

The 29.75 and 29.8 mm valves need inlet seats machined to their size; the 28.75 and 28.8 mm ones fit on seats reconditioned to the factory size.

Fit all 8 valves from the same set and replace the inlet valve stem seals at the same time.

Technical guide

The brands offered

	A Florida manufacturer founded in 1978, FERREA Racing Components makes each valve from a single forged bar, finished on CNC machines; its parts run in NASCAR and drag racing.
	A Californian designer of racing valvetrain parts for more than thirty years, SUPERTECH Performance forges then CNC machines its valves and checks every batch by ultrasound, X-ray and laser.
	A Belgian engine specialist known for its camshafts, CATCAMS also develops springs, followers and valves, each profile being designed for a given engine and use, from road to rally.

How to choose

The groove is the notch at the end of the stem where the collets that hold the retainer sit. On the TU5J4, the choice is made on size, then material:

When reinforced valves become necessary

• Higher lift camshafts or stiffer springs
• Higher rev limit
• Supercharger or turbo added
• Cylinder head rebuilt for rallies, hill climbs or track
• Worn original valves or seats already reground

Compatible vehicles

Related products

With the TU5J4 cylinder head off, replace its 8 exhaust valves as well: