Reinforced inlet valves VAG 2.0 8V

VW, SEAT and SKODA engines covered

The Volkswagen group's 2.0 eight-valve four-cylinder, rated at 115 to 116 hp, powered from 1990 to 2010 the Golf III and IV, the Bora, the New Beetle and the Passat B3 / B4, as well as the Seat Toledo I, Ibiza II, Cordoba and Alhambra and the Skoda Octavia I, under many engine codes: ABA, ADY, AGG, AKR, AEG, APK, AQY, AZJ and related ones.

It has only one inlet valve per cylinder, 4 per engine, operated by hydraulic tappets. VW parts 078 109 601 B then 078 109 601 E (06A 109 601 E on some versions) have a 39.5 mm head, a 7 mm stem and a length of 91.9 mm, with valve stem seal 027 109 675. Sharper camshaft, supercharger or track use: tuning adds heat and impacts on these large heads.

SUPERTECH and FERREA reinforced inlet valves

On the Volkswagen group's 2.0 8V, each cylinder gets only one inlet valve: it alone must let through all of the fresh mixture, before dropping sharply back home, its stem travelling through the guide, under the command of a hydraulic tappet. Its large head works between 400 and 550 °C. The chrome-silicon of common valves, which keeps 500 MPa at 500 °C, offers only 250 at 600 °C, 50 % less strength: a head of nearly 40 mm weakened like this ends up distorting, marking its seat face, then letting compression escape.

SUPERTECH produces its three part numbers in stainless steel before applying black nitriding: this hardened skin shields the stem, which degrades more slowly under guide friction, even with a supercharger or springs rated higher. The stem is slimmed just under the head, the rear face of the head is reworked to ease the airflow, and the head face is slightly dished. The 7 mm stem stays at VW size and fits the stock guides; each set gathers the 4 valves of one engine, all at the same size.

The three sets enlarge the 39.5 mm original head: 40 mm (+0.5 mm), 41 mm (+1.5 mm) or 42 mm (+2.5 mm, with length increased to 92.2 mm). The mixture then crosses a widened opening at the seat, each cylinder draws a richer charge and the 2.0 8V finds extra power, provided a workshop recuts the 4 inlet seats to the chosen diameter.

Inlet valve technical specification

Fitting details

The SUPERTECH valves have three grooves and are fitted with the KPR-VW7-T 3 groove collets for a 7 mm stem, which the manufacturer lists for these engines.

The 40, 41 and 42 mm heads exceed the 39.5 mm factory size: the 4 inlet seats are machined to the diameter of the chosen head before reassembly.

The hydraulic tappets take up the clearance on their own: no adjustment is needed after the valves are replaced.

Technical guide

The brand offered

SUPERTECH Performance has worked in California for three decades and more, designing and then machining competition valves, springs and valve guides. Each series goes under ultrasound, X-ray and laser before shipping, and its valves come in several alloys.

How to choose

The groove is the slot machined at the stem tip; there the collets retain the top retainer, and their profile follows the groove count. Here, size comes first:

When reinforced valves become necessary

• Reground camshaft or stiffer return springs
• Fuel cut-off moved past the factory value
• Forced induction added to the 2.0 8V
• Head rebuilt for track, stages or hill climbs
• Pitted stock valves or seats reground several times

Compatible vehicles

OEM part number (inlet valve): 078 109 601 B, 078 109 601 E, 06A 109 601 E

Related products

With the 2.0 8V head on the bench, also replace its exhaust valves and inlet valve stem seals: the two parts made for this engine are below.