SUPERTECH inlet and exhaust valve stem seals Mitsubishi Eclipse 420A set of 16

Mitsubishi engines concerned

This complete set of 16 seals is for the 420A engine, a Chrysler-designed 2.0 with 16 valves and 6 mm stems, which Mitsubishi fitted to the 141 hp Eclipse II (D3_A) 2.0 RS from 1995 to 1999.

The 420A's 16 valves, 8 inlet and 8 exhaust, all take the same SUPERTECH VSI-M6E integral seal, so this set of 16 covers the head in one go. Each seal hugs the guide and meters the oil going down to the stem.

SUPERTECH inlet and exhaust valve stem seals

On this 2-litre four, each seal does two jobs: lubricate the 6 mm stem and keep surplus oil in the head. Hardened by 25 years of heat, the rubber ends up leaking: the 420A burns more oil than when new, the Eclipse puffs blue on a cold start or when restarting after a long idle, and deposits gradually build on the 16 valves and the 4 spark plugs of the 420A.

SUPERTECH's VSI-M6E is an integral Viton (FKM) seal matching the 420A's 11 mm guide and 6 mm stem. With its 16 pieces, this set renews the inlet seals and the exhaust seals in a single job: one part number for the whole Chrysler head of the Eclipse.

Stem seal technical specifications

Stem seal installation

Technical guide

The brand offered

For over 30 years, out of San Jose, California, SUPERTECH has produced competition valves plus its own springs, guides, stem seals. Ultrasound, radiography and laser control its manufacture, then renowned engine builders validate it in dyno tests and racing.

Inlet or exhaust?

On the 420A, SUPERTECH keeps to one part: the VSI-M6E integral seal in Viton (FKM) serves the 8 inlet valves just as well as the 8 exhaust valves, 6 mm stem and 11 mm guide throughout. SUPERTECH's data give this Viton 204 °C (400 °F) in continuous service, a handy margin on the exhaust side. This set of 16 is enough for a complete engine.

When valve stem seals must be replaced

• Higher oil consumption, Eclipse smoking blue at start
• 420A head removed for overhaul
• Changing all the 420A's guides
• Firmer springs or racing valves fitted

Vehicle compatibility

MITSUBISHI

Remember the Eclipse 420A uprated valves

With the 420A head off, inspect its 16 valves as well. SUPERTECH builds uprated exhaust valves suited to the Eclipse 2.0 RS: