Reinforced cylinder head gasket Mitsubishi 4G63-T Eagle Talon JMC S350 Soueast DX7

The Mitsubishi engines covered

The 2.0-litre turbocharged petrol 4G63-T engine powers the Eagle Talon, the JMC S350 and the Soueast DX7, listed below.

For this 4G63-T, our sources confirm no original gasket part number, so the original bore, construction and thickness remain unstated. The standard gasket is sized for standard combustion pressure; when it rises, the clamping load fades, the head lifts and coolant passes into a cylinder.

Reinforced cylinder head gaskets

Sealing does not depend on the gasket alone: the bolts or studs that press the head onto the block play just as large a part. A composite gasket settles for good beyond 100 N/mm² of admissible stress; the 301 stainless steel of MLS gaskets withstands 517 N/mm², 5 times more, and regains its shape after every combustion.

This page offers one part number from the American maker Cometic, a specialist in racing gaskets: the H1528SP6060S, in multilayer steel MLS, with an 87 mm bore and a thickness of 1.52 mm. It is sold individually.

Technical specifications

A gasket's volume is the void it leaves above each piston. That void enlarges the combustion chamber and lowers the compression ratio; only gaskets of the same bore are compared.

Preparation and fitting

Before fitting, check the flatness of the head and block with a straightedge, and have resurfaced whichever part requires it. Cometic supplies this gasket coated: add no sealing paste.

Technical guide

The construction offered

MLS Cometic A stack of embossed, riveted stainless steel sheets. The outer sheets carry active beads around each cylinder and each fluid passage. A moderate clamping load is enough to seal, with little bore distortion. It is the versatile choice, from the built naturally aspirated engine to light boost.

Choosing bore and thickness

Gasket bore. The Cometic MLS is offered in 87 mm (H1528SP6060S), in that bore only.

Thickness. No original thickness is confirmed for this engine. A thicker gasket enlarges the combustion chamber and lowers the compression ratio; a thinner one reduces it and raises the ratio.

As the original thickness is not confirmed, read with a dial gauge how far the pistons stand proud of the block's gasket face, above all if the removed gasket is thinner than 1.52 mm: that figure sets the clearance left between piston and head.

The brand

Cometic Gasket, Inc. is an American maker of gaskets and sealing solutions for engines, based in Concord, Ohio, since 1989. It is known for the gasket made to measure, at the bore and thickness requested, built entirely in the United States from American raw materials.

Advantages over the original gasket

When a reinforced gasket becomes necessary

• Adding forced induction, or raising boost on an already turbocharged engine
• Cylinder rebored beyond what the 87 mm bore of the gasket offered covers
• Looking for a compression ratio different from standard, higher or lower
• Engine that has already lost its gasket, or is consuming coolant
• Competition use, where the gasket goes through repeated temperature rises

Vehicle compatibility

OEM part number: no confirmed original part number.

Important: the part number on this page is intended for the 4G63-T engines of the vehicles in the table above: read your vehicle's engine code and check the 87 mm bore before ordering.

Why switch to a reinforced gasket?

When the standard gasket reaches its limit, the reinforced gasket takes over: under higher combustion pressure it does not crush and keeps its shape.

On an engine that is already turbocharged from the factory, the slightest rise in pressure or power loads the head gasket first. The reinforced gasket prevents the leak and costs much less than the head removal it would cause, with no long spell off the road.