Reinforced inlet valves MITSUBISHI Lancer Evolution X 4B11T

MITSUBISHI engines covered

The 4B11T is the 2-litre, 16-valve, twin-cam turbo four-cylinder of the Lancer Evolution X (CZ4A), built from 2007 to 2014. Its aluminium block and twin-scroll turbo make it a sought-after base for tuning.

It has 8 inlet valves, originally 1010A220. Raised boost, sharper camshafts or a higher rev limit load them much harder than in standard form.

FERREA and SUPERTECH reinforced inlet valves

Each inlet valve opens the way for the air compressed by the turbo, closes onto its seat every cycle and slides constantly in its guide, at 400 to 550 °C. A standard chrome-silicon steel drops there from 500 MPa at 500 °C to 250 MPa at 600 °C, 50 % less strength.

FERREA's 6000 series, in EV8 stainless steel, keeps 650 MPa at 500 °C and 550 MPa at 600 °C: 30 % and then 120 % better than chrome-silicon steel. The Competition Plus, in stainless steel with a chrome-plated stem, offers 20 % more hot strength and fatigue resistance and a seat that lasts 25 % longer. The SUPERTECH valve, in black nitride stainless steel, has a hardened surface that protects the stem from wear.

At +1 mm the head grows from 35 to 36 mm with the same stem and length: air passes the seat more freely, the cylinder fills better and the engine gains power, once the 8 inlet seats are machined to that diameter.

Inlet valve technical specification

F6294, F2175P and MIVN-1017 are standard size; F6295, F2176P and MIVN-1019 are +1 mm.

Fitting details

The FERREA valves have a single groove: use collets made for that profile, such as K10091, and check their seating before releasing the springs.

With the 35 mm head the inlet seats keep their factory size; with 36 mm the workshop machines all 8 seats to that diameter.

Technical guide

The brands offered

	A valve maker since 1978, FERREA produces racing parts in Florida and Argentina, from the 6000 series in EV8 stainless steel to the chrome-stem Competition Plus. Its valves are found in rally heads as well as in highly tuned turbo engines.
	A Californian racing valvetrain specialist for more than thirty years, SUPERTECH Performance makes valves, springs and guides. Ultrasound, X-ray and laser measurement approve each batch before it goes into competition engines.

How to choose

The groove is the recess cut at the end of the stem; the collets sit in it to retain the upper retainer. The SUPERTECH valves are black nitride stainless steel; you choose the 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 time attack
• Marked original valves or seats already reground

Compatible vehicles

OEM part number (inlet valve): 1010A220

Related products

With the 4B11T cylinder head off, replace the 8 exhaust valves at the same time.