Reinforced exhaust valves Peugeot Citroën EW10J4

Peugeot and Citroën engines covered

The EW10J4, the naturally aspirated 2 litre 16-valve four-cylinder of the PSA group, powered the Peugeot 206 S16, 206 CC and 206 SW, the 307, 406, 407, 607, 806 and 807, as well as the Citroën Xsara, Xsara Picasso, C4, C4 Picasso, C5, C8 and Evasion from 1999 to 2014: 135 hp as the RFR, then 120 to 143 hp as the RFN depending on the model.

It has 8 exhaust valves, two per cylinder, loaded on every cycle by the burnt gases, especially when the engine runs for long periods near the rev limit.

SUPERTECH reinforced exhaust valves

On a naturally aspirated engine, the metal of an exhaust valve head reaches 760 to 870 °C; it exceeds 1,000 °C when turbocharged. About 75 % of that heat leaves through the seat and 20 % through the guide. An EV8 family steel still holds 550 MPa at 600 °C but only 300 MPa at 800 °C: beyond that, the head fatigues, distorts and the seal is lost.

SUPERTECH makes this valve in Inconel, a nickel base superalloy that keeps 860 MPa at 732 °C and 554 MPa at 816 °C, about 85 % more than EV8 family steel around 800 °C. It keeps the standard size: 29.0 mm head, 5.97 mm stem.

Exhaust valve technical specifications

The set keeps the 29.0 mm head, the 5.97 mm stem and the 103.35 mm length.

Valve fitting

Check the collets on reassembly: they must be in good condition and seat properly in the stem groove.

The 5.97 mm stem slides in the guides: check their clearance and replace the valve stem seals at every rebuild.

Regrind the exhaust seats with the new valves to restore an even contact band.

Technical guide

Our brand

SUPERTECH, an American maker of racing valvetrain parts, offers one Inconel exhaust valve in standard size for the EW10J4, with a 29.0 mm head.

How to choose

One version is offered for this engine:

When reinforced valves become necessary

• More aggressive camshafts
• Track or hill climb use
• Marked or leaking exhaust valves
• Cylinder head rebuild

Vehicle compatibility

OEM part number (exhaust valve):

Don't forget the inlet valves

While the EW10J4 cylinder head is off, also replace the inlet valves and the valve stem seals.