Inlet valve guides Mitsubishi 4G63

Applicable Mitsubishi engines

This set equips the inlet side of the 2.0 litre Mitsubishi 4G63 four-cylinder, naturally aspirated or turbocharged (4G63T). It goes into Lancer Evolution, Eclipse, Galant VR-4 and Outlander Turbo models, among others.

The engine's 16 valves split into eight inlet and eight exhaust, each running in a guide pressed into the head. For this set the FERREA catalogue gives a 6.57 mm valve stem, and SUPERTECH a guide made for a 6.6 mm stem; the sizes below are the makers' own.

FERREA and SUPERTECH inlet valve guides

In the 4G63 each inlet valve slides in its guide, which keeps it square to the seat, takes some of its heat away and retains the stem seal. As soon as clearance grows, the valve tilts and seats badly: oil creeps down the stem, giving blue smoke, more frequent top-ups and falling compression. A new guide gives the stem back a controlled clearance and a clean contact on the seat.

FERREA's copper bronze comes from the United States, and its in-house heat treatment, described in the catalogue, targets heat dissipation, high-temperature stability, slow wear and lubricity. Tight-tolerance CNC machining suits valves in titanium or stainless steel. SUPERTECH chooses a manganese bronze that, per the brand, carries heat away much more effectively than the standard sintered guides. The set contains the eight inlet guides of the engine. They are most often fitted with reinforced valves.

Valve guide technical specifications

Valve guide installation

Technical guide

Our brands

	Founded in 1978 in Fort Lauderdale, Florida, FERREA also builds in Argentina. Its catalogues gather guides, valves, springs and stem seals for competition.
	SUPERTECH has been based in Silicon Valley for over thirty years. Guides, springs, titanium retainers and valves are drawn there for racing, calculated by finite elements, then proven with engine builders.

Standard or oversize?

Each brand lists two sizes: standard, then 0.025 mm (0.001") oversize. SUPERTECH's outside diameter moves from 12.08 mm to 12.1 mm.

Manganese bronze

Manganese bronze is a copper alloy enriched with manganese, with a little aluminium, iron and zinc. It stands up well to corrosion and to sliding wear, which explains its use in heavily loaded bearings, and so in a valve guide, rubbed by the stem on every cycle.

When valve guides must be replaced

• Oil passing through the inlet stems
• Reinforced valves meant for a worn head
• Track, rally or drift head to bring back to new
• Valve train reworked from end to end

Vehicle compatibility

Important: these guides are given for the turbo 4G63 and for the Eclipse one, both double overhead cam. Other 4G63 engines are excluded.

Remember the exhaust guides and valve stem seals

New guides call for new stem seals; FERREA lists the VS1011 for the inlet side in its catalogue.