Reinforced inlet valves FORD Focus Zetec 2.0 16V

FORD engines covered

The Zetec 2.0 is Ford's 2.0 litre inline four with 16 valves and twin overhead camshafts. In the first generation Focus (saloon, three and five door, Turnier estate) it delivers 112 to 131 hp, from 1998 to 2005, under the codes EDDB, EDDC, EDDD, EDDF and 20LS9X.

The engine has 8 inlet valves with a stem of about 6 mm (6.03 to 6.035 mm depending on the maker). More compression, a sharper camshaft, forced induction or a higher rev limit load them far beyond standard use.

SUPERTECH and FERREA reinforced inlet valves

In the Zetec, the inlet valve opens the way for fresh air and shuts it again straight away, a move repeated dozens of times per second as the engine gains revs. Its head knocks against the seat on every return, and its stem shuttles back and forth through the guide. It runs at 400 to 550 °C; in that window the production chrome-silicon steel is already past its best, dropping from 500 MPa at 500 °C to 250 MPa at 600 °C, only slightly hotter, a fall of 50 %. Any rise in lift, spring rate, revs or inlet pressure adds impacts, frictional wear and heat.

The SUPERTECH valves listed here come from a chrome and nickel stainless steel designed for motorsport, a cousin of EV8 (21-4N): it retains 650 MPa at 500 °C, 30 % above production steel, then 550 MPa at 600 °C, 120 % above. Black nitriding gives them a harder, slicker skin that spares the stem in the guide. The FERREA valves are Competition Plus parts in stainless steel with a chromed stem, offering 20 % extra heat and fatigue strength and 25 % longer seat life.

Besides the standard size (32 mm head), this page lists a +1 mm size (33 mm, FERREA) and a +2 mm size (34 mm, SUPERTECH). Only the head grows: the seat flows more generously, the chamber takes in extra air and output climbs, provided all 8 inlet seats are machined to the chosen diameter.

Inlet valve technical specification

FERREA valves: 5.25 mm stem tip.

Fitting details

The +1 mm and +2 mm sizes need inlet seats cut to 33 mm or 34 mm; at standard size the seats keep their diameter.

The SUPERTECH valves measure 97.1 mm and the FERREA valves 97.55 mm.

Technical guide

Our brands

	SUPERTECH Performance, located in San Jose, California, has devoted more than thirty years to racing valves, springs and retainers. Every part goes through ultrasonic, radiographic and laser inspection, and each model grows out of work with engine builders around one specific head.
	Set up in 1978 in Fort Lauderdale (Florida) by a pair of Argentine engine builders, FERREA Racing Components shapes every valve in one piece from a forged bar, then machines it end to end on CNC equipment. Its parts run in NASCAR as well as drag racing.

How to choose

Collets sit in the groove by the stem tip, holding the upper retainer. All these valves share that layout, so you only pick size and brand.

When reinforced valves become necessary

• Sharper camshaft or more energetic springs
• Supercharger or turbo grafted onto a formerly naturally aspirated engine
• Rev ceiling raised
• Head built for track, rally or hillclimb
• Tired stock valves or seats already reground once

Compatible vehicles

Related products

Use the head job to renew the 8 exhaust valves of the Zetec-E 2.0 16V as well, together with a set of fresh stem seals fitted at the same time: