Reinforced inlet valves VOLKSWAGEN 1.8 T 20V

The VOLKSWAGEN engines covered

At Volkswagen, the 1.8 T 20V is the 1,781 cc turbocharged four-cylinder with five valves per cylinder, three inlet and two exhaust. From 1996 to 2010 it powers the Golf IV GTI, Bora, New Beetle, Passat B5, Polo GTI and Sharan, from 150 to 180 hp.

Its 12 original inlet valves carry part number 058 109 601 C: 26.9 mm head, 6 mm stem, 105.1 mm length. Under boost, a remap, a bigger turbo or sharper camshafts load them far beyond stock use.

SUPERTECH and FERREA reinforced inlet valves

At high revs, each 1.8 T inlet valve lifts and lands back on its seat dozens of times a second, its stem sliding constantly in the guide, at 400 to 550 °C. In that range the original chrome-silicon steel drops from 500 MPa at 500 °C to 250 MPa at 600 °C: half of its strength, 50 %, is gone.

The SUPERTECH valves are black nitride stainless steel: the treatment hardens and smooths the surface, limiting stem wear in the guide. The FERREA F1556P and F1557P belong to the Competition Plus series, for which the manufacturer claims 20 % more hot strength and fatigue resistance, and 25 % longer seat life.

In the +1 mm size the head grows from 26.9 to 27.9 mm, with stem and length unchanged: the airway widens, the cylinder fills better and the engine gains power. The inlet seats are then cut to the new size.

Inlet valve technical specification

AIVN-1103S-12 and AIVN-1106S-12: to be fitted with SUPERTECH KPR-6S/7 collets.

Fitting details

SUPERTECH requires its KPR-6S/7 collets with the 1-groove AIVN-1103S-12 and AIVN-1106S-12 valves. The 3-groove valves, AIVN-1103-12 and FERREA, keep original-type collets.

The +1 mm size (F1557P*12, AIVN-1106S-12) needs inlet seats cut to 27.9 mm.

These engines use hydraulic tappets: there is no valve clearance to set after the replacement.

Technical guide

Our brands

	SUPERTECH has been making racing valvetrain parts in San Jose, California, for more than thirty years. Each valve follows the design of a specific cylinder head, goes through ultrasonic, X-ray and laser checks, then runs in its partners' engines on circuits and drag strips.
	FERREA Racing Components, founded in 1978 in Fort Lauderdale, Florida, by two engine builders from Argentina, forges its valves in one piece from bar stock and then machines them on CNC equipment. Its valves run in NASCAR and dragster engines.

How to choose

The groove is the notch in the stem where the collets that hold the valve sit.

When reinforced valves become necessary

• Higher-lift camshafts or firmer springs
• Raised rev limit
• Fitting a supercharger or turbocharger
• Cylinder head rebuilt for circuit, drift or rally use
• Original valves marked, worn or already reground

Compatible vehicles

OEM part number (inlet valve): 058 109 601 C

Related products

A rebuilt 1.8 T cylinder head also gets new exhaust valves and valve stem seals. The parts for this engine: