FERREA inlet valve stem seals Mitsubishi Hyundai 4B11-T G4KF

Mitsubishi and Hyundai engines concerned

Intended for 5.5 mm stem inlet valves, this set targets the Mitsubishi 4B11-T, a 2.0 litre 16-valve turbo four-cylinder used in the Lancer Evolution X and Lancer Ralliart, as well as its Hyundai cousin, the G4KF of the Genesis Coupe 2.0 T.

The head carries 8 inlet valves, two per cylinder. Mitsubishi caps each guide with an original seal that meters oil onto the stem, part number MN183952, used on both inlet and exhaust.

FERREA inlet valve stem seals

Placed at the top of the guide, this small seal regulates oil flow to the stem: a very thin film is enough, and without it stem and guide would wear fast. Tired or hardened by heat, it lets more oil into the chamber, which shows on the dipstick, as blue smoke on starting or after idling, and as deposits on valves and plugs.

FERREA moulds it in Viton (FKM), a rubber built for high temperatures, with a spring that presses the lip onto the 5.5 mm stem for better oil control under hard use. This set of 8 covers the whole inlet side of the 4B11-T or G4KF; for the exhaust, FERREA supplies a distinct seal, sold separately.

Stem seal technical specifications

Stem seal installation

Technical guide

The brand offered

FERREA produces its own valvetrain components in its Florida and Argentine workshops, from the valve to the stem seal. This production is aimed at high-output and racing engines; the spring in its Viton seals keeps them tight even at high revs.

Inlet or exhaust?

FERREA splits the two sides of the 4B11-T: VS1025 for the inlet and VS1024 for the exhaust, the latter rated for high temperatures. Both are made of Viton (FKM), both carry a lip spring and both suit a 5.5 mm stem, yet each one keeps to its own place in the head. This four-cylinder needs 8 seals on the inlet and 8 on the exhaust.

When valve stem seals must be replaced

• Higher oil consumption, blue smoke
• Valves removed or head being renovated
• Valve guides changed for new ones
• Fitting uprated springs or new valves

Vehicle compatibility

Mitsubishi / Hyundai

OEM part number (Mitsubishi stem seal): MN183952

Remember the exhaust valve stem seals

Change the 8 inlet seals of the 4B11-T or G4KF with the 8 exhaust seals. For these engines FERREA supplies the VS1024 set: