Reinforced exhaust valves Citroën Xsara VTS ZX XU10J4RS

Citroën engines covered

At Citroën, the XU10J4RS 2.0 16V powers the Xsara (N0) in 2.0 16V, VTS and 2.0 i 16V form from 1998 to 2005, and the ZX (N2) 2.0 and 2.0 i 16V in 1996 and 1997.

Its cylinder head takes 8 exhaust valves with a 30.8 mm head in standard size and a 6 mm stem. The two sets offered are 105.5 mm (9249002M) and 105.3 mm (PEEVN-28693-8, 5.96 mm stem) long.

SUPERTECH reinforced exhaust valves

Without forced induction, an exhaust valve head reaches 760 to 870 °C; with a turbo or a supercharger it goes past 1,000 °C. Close to three quarters of that heat leaves through the seat (about 75 %) and a fifth through the guide (about 20 %). An EV8 family exhaust steel holds 550 MPa at 600 °C but only 300 MPa at 800 °C, hence heads that overheat, fatigue, warp and end up leaking.

The SUPERTECH PEEVN-28693-8 combines stainless steel and black nitriding, a hard layer that protects the stem from friction in the guide.

Exhaust valve technical specifications

Valve fitting

Before any reassembly, check that the collets match the lock groove of the selected valves.

In standard size, both sets only need exhaust seats cut back at 30.8 mm.

With a 6 mm stem (9249002M) or a 5.96 mm stem (PEEVN-28693-8), guide clearance must be checked according to the chosen version.

Technical guide

Our brands

	SUPERTECH Performance, a Californian racing valve maker, supplies the PEEVN-28693-8 in black nitrided stainless steel, standard size, for the XU10J4RS of the Xsara and ZX.
	CATCAMS, a European camshaft specialist, provides the 9249002M for this engine, grouped as a set of 8, 30.8 mm head.

How to choose

Same head for both sets; stem and finish set them apart:

When reinforced valves become necessary

• More aggressive camshaft profile or reinforced springs
• Rally, hill climb or track
• Fitting a turbo or a supercharger
• Head rebuilt with worn exhaust valves

Vehicle compatibility

OEM part number (exhaust valve):

Don't forget the inlet valves

A Xsara VTS or ZX 16V cylinder head on the bench is the right time to replace the inlet valves and valve stem seals too.