Reinforced inlet valves PEUGEOT CITROËN EW10J4 EW10J4S

PEUGEOT and CITROËN engines covered

The EW10J4 and EW10J4S are the PSA 2.0 litre 16 valve fours of the EW family. From 1999 to 2014 they power the Peugeot 206, 307, 406, 407, 607, 806 and 807 and the Citroën Xsara, Xsara Picasso, C4, C4 Picasso, C5, C8 and Evasion, from 120 to 180 hp; the EW10J4S drives the most powerful 206 RC, 307 and C4.

The engine has 8 inlet valves, two per cylinder. A remap, sharper camshafts or race preparation put them through much higher temperatures and impacts than stock use.

SUPERTECH reinforced inlet valves

Each time the cam pushes it down, the inlet valve opens the way for the mixture, then presses back onto its seat with an impact, and its stem keeps gliding in the guide. In service it sees 400 to 550 °C: factory chrome-silicon steel goes there from 500 MPa at 500 °C to only 250 MPa at 600 °C, losing 50 % of its strength. Any rise in revs or lift increases this effort.

The material chosen by SUPERTECH here is a chrome-nickel race stainless from the EV8 (21-4N) family, which holds 650 MPa at 500 °C, 30 % above the original steel, and 550 MPa at 600 °C, 120 % above. Its stem is chrome plated and the valve stays at the maker's standard size: 33.3 mm head, 5.98 mm stem and 106.2 mm length.

Inlet valve technical specification

PEIVN-28594-8: set of 8 valves at the maker's standard size.

Fitting details

No reinforced collets, valve stem seals or valve guides are listed for the EW10J4 and EW10J4S: the original PSA parts are refitted, preferably new.

At standard size, the valve sits on the factory inlet seats; lapping or a light regrind is enough during the rebuild.

Technical guide

The brand offered

It is in San Jose that SUPERTECH has spent more than thirty years developing valvetrains for competition engines. Each engine gets its own valve, verified with ultrasound scans, X-ray imaging and laser measurement, then approved in racing by engine builders.

How to choose

Only a single reference exists here for the EW10J4 and EW10J4S: at factory size, it avoids any seat machining and mainly brings a tougher material and finish.

When reinforced valves become necessary

• More aggressive camshafts, firmer valve springs
• Red line moved up after a remap
• Forced induction grafted onto the EW10
• Head rebuilt for track, rally or slalom
• Worn or marked PSA valves, or seats lapped several times

Compatible vehicles

Don't forget the exhaust valves

During a head rebuild the exhaust valves wear as much as the inlet ones; for the EW10J4 of the 206 S16 we offer a reinforced version: