Reinforced inlet valves MITSUBISHI 4G63

MITSUBISHI engines covered

The twin-cam 4G63 is Mitsubishi's 2-litre, 16-valve four-cylinder, naturally aspirated or turbocharged (4G63T). It powers the first and second generation Eclipse and the Lancer Evolution VIII, two very popular bases for tuning.

It has 8 inlet valves, two per cylinder. Raised boost, sharper camshafts or a higher rev limit load them well beyond what the production engine was designed for.

FERREA and SUPERTECH reinforced inlet valves

The inlet valve lets the fresh charge in, drops back onto its seat at every closing and slides constantly in its guide, at 400 to 550 °C. An ordinary chrome-silicon steel goes from 500 MPa at 500 °C to 250 MPa at 600 °C there: half of its strength, 50 %, is gone.

FERREA's 6000 series is EV8 stainless steel, which keeps 650 MPa at 500 °C and 550 MPa at 600 °C, 30 % and then 120 % more than chrome-silicon steel. The Competition Plus, in stainless steel with a chrome-plated stem, adds 20 % hot strength and fatigue resistance and a seat that lasts 25 % longer. SUPERTECH supplies black nitride stainless steel, surface-hardened to limit stem wear.

Above standard size the head grows to 34.5, 35 or 36 mm with the same stem and length: the seat opening widens, the cylinder fills better and the engine gains power, once the 8 inlet seats are machined to the chosen diameter.

Inlet valve technical specification

F6026, F1826P and MIVN-1007 are standard size; MIVN-1008 is +0.5 mm, F6052, F1452P and MIVN-1009 are +1 mm, MIVN-1010 is +2 mm.

Fitting details

The K10035 collets must suit the groove of the chosen valve: check this before compressing the springs.

At 34 mm the inlet seats keep their factory size; from 34.5 to 36 mm the workshop machines all 8 seats to the head diameter.

Technical guide

The brands offered

	Based in Florida since 1978, FERREA also manufactures in Argentina, producing racing valves from the 6000 series in EV8 stainless steel to the chrome-stem Competition Plus. Builders of road heads and rally engines alike use them routinely.
	For more than thirty years SUPERTECH Performance has designed valves, springs and guides for competition in California. Every batch is checked by ultrasound, X-ray and laser, then proven on circuit and drag engines.

How to choose

The groove is the recess machined near the stem tip; the collets sit in it to hold the upper retainer. All SUPERTECH valves are black nitride stainless steel; the choice is about size and, for FERREA, the series:

When reinforced valves become necessary

• Raised boost or a larger turbo
• Higher-lift camshafts or stiffer springs
• Higher rev limit
• Cylinder head rebuilt for rallying, track or drag racing
• Marked original valves or seats already reground

Compatible vehicles

Related products

With the 4G63 cylinder head off, replace the 8 exhaust valves at the same time.