Reinforced inlet valves BMW M42B18 M44B19

BMW engines covered

The 1.8 litre M42B18, in its 6 mm valve stem version fitted from September 1992, and the 1.9 litre M44B19 are the 16-valve inline four-cylinder petrol engines of the BMW 318i, 318is and 318ti Compact of the E36 3 Series, of their coupe and convertible versions, and of the Z3 1.9.

Each of these engines has 8 inlet valves, BMW part number 11 34 1 739 822, the same as on the M50 with VANOS: 33.0 mm head, 6.0 mm stem, 106.1 mm length, held by 3-groove collets. Designed for the standard engine, they quickly reach their limits once sharper camshafts, firmer springs, higher revs or forced induction are fitted.

SUPERTECH and FERREA reinforced inlet valves

Dozens of times per second at high rpm, the inlet valve opens to let fresh air in, drops back onto its cylinder head seat and slides in its guide. It works between 400 and 550 °C. At these temperatures, the chrome-silicon steel of the original valves only withstands 500 MPa at 500 °C, then 250 MPa at 600 °C, i.e. 50 % less. Every gain in lift, spring rate, revs or boost pressure adds impacts, friction and heat, and wears the valve faster.

The valves offered here are forged from a competition chrome-nickel stainless steel of the EV8 (21-4N) type: 650 MPa at 500 °C, i.e. 30 % more strength than the original steel, and 550 MPa at 600 °C, i.e. 120 % more. The FERREA valves belong to the Competition Plus range, for which the manufacturer states 20 % more hot strength and fatigue resistance and a seat that lasts 25 % longer. SUPERTECH supplies them in black nitrided stainless steel, a harder and smoother surface that causes less friction and wear; FERREA gives them a hard chrome stem.

In +1 mm oversize, the head grows from 33 to 34 mm while the stem and length stay as original. The passage at the seat widens, the cylinder fills better and the engine gains power, provided the cylinder head seats are cut to this new diameter.

Inlet valve technical specifications

Valve fitting

Valves and collets always go together: the 3-groove SUPERTECH valves take KPR-VW6-T collets, the single groove ones KPR-6S-7 collets. The original collets are never fitted on a single groove valve.

With the +1 mm oversize, the cylinder head seats must first be cut to the diameter of the new head, a job to plan during the cylinder head rebuild.

Technical guide

Our brands

	SUPERTECH has been making competition valvetrain parts in San Jose, California, for more than 30 years. Its valves are designed engine by engine, checked by ultrasound, X-ray and laser measurement, then validated by engine builders, from circuit racing to drag racing.
	FERREA Racing Components, set up in 1978 in Fort Lauderdale, Florida, by two engine builders from Argentina, makes everything in its own workshops. Each valve is forged in one piece from steel bar stock and then CNC machined; they are found in NASCAR, drag racing and circuit racing.

How to choose

The collets sit in the groove, just below the retainer. Its shape sets how the valve is held, and therefore what it can withstand.

When reinforced valves become necessary

• Sharper camshafts or firmer valve springs fitted
• Raised maximum rpm
• Conversion to forced induction, by turbocharger or supercharger
• Cylinder head rebuilt for a circuit, drift or rally engine
• Original valves damaged, worn or already at repair size

Vehicle compatibility

OEM part number (inlet valve): 11 34 1 739 822

Don't forget the exhaust valves

A rebuilt cylinder head takes new valves on both the inlet and exhaust sides, as well as new valve stem seals. The exhaust valves for this engine are available here: