Reinforced head gasket Opel Vauxhall 1.6 16V C16XE X16XE X16XEL Y16XE

The Opel engines covered

Opel's 1.6 litre 16-valve inline four comes as the C16XE, X16XE, X16XEL and Y16XE. It powers the Opel Corsa B, Tigra, Vectra B, Astra F and G and Zafira A, and their Vauxhall cousins the Corsa, Tigra, Vectra, Astra and Zafira in the table below. A single head covers the four cylinders: the gasket is sold individually, one per engine.

The manufacturer part number of the standard gasket is 6 07 491, and 56 07 865 for the Y16XE; neither the bore, nor the thickness, nor the construction appears in any published documentation. It is sized for the original combustion pressure: beyond it, the clamping load loses its grip, the head lifts and coolant passes into a cylinder.

Reinforced cylinder head gaskets

The gasket does not seal on its own: the fasteners that clamp the head to the block count as much as it does. Beyond 100 N/mm², a composite gasket takes a permanent set; the 301 stainless steel of the MLS withstands 517 N/mm², 5 times more, and recovers its shape with every combustion. The raised features of the outer sheets carry the clamping load around each cylinder and each fluid passage, without any machining of the block.

This page gathers the part numbers of a single racing manufacturer, Cometic, in multi-layer MLS construction, with three gasket bores, 79, 80 and 82 mm. Thicknesses run from 0.686 to 3.556 mm, enough to adjust the compression ratio without altering either the pistons or the head. As a rule, the gasket bore chosen is at least 0.5 mm larger than the actual cylinder bore. Each part number is sold individually, one gasket per engine.

Technical specifications

Gasket volume means the space left open above each cylinder. It is added to the combustion chamber and lowers the compression ratio by the same amount. Keep the comparison to gaskets of the same bore.

Preparation and fitting

Before fitting, run a straight edge over the head and the block to check their flatness, and have the surface that needs it resurfaced. Add no sealing paste: Cometic gaskets arrive already coated.

Technical guide

The construction offered

Cometic MLS Stamped stainless steel sheets, laid over one another and riveted. The outer sheets show active beads around each cylinder and each liquid passage. The gasket seals with a moderate clamping load and barely distorts the bore. It is the all-round solution, from the tuned naturally aspirated engine to sensible boost.

Choosing bore and thickness

Gasket bore. The Cometic MLS comes in 82 mm (C4257), 79 mm (H1568SP2 and H2407) and 80 mm (H1568SP1).

Thickness. The manufacturer gives no thickness for the standard gasket: only the measurement of the gasket you remove counts. A thicker gasket enlarges the combustion chamber and lowers the compression ratio; a thinner one reduces it and raises the ratio.

With no published original thickness, use a dial gauge to measure how far the pistons protrude above the block deck: that gives the clearance remaining between piston and head, particularly with the thinnest gasket.

The brand

Cometic Gasket, Inc., an American company born in 1989 in Concord, Ohio, designs engine gaskets and sealing solutions. It has made a speciality of the custom gasket, at the bore and thickness requested, built entirely in the United States from American 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 bore of the gaskets offered (79, 80 and 82 mm) 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: 6 07 491.

Important: the gaskets on this page are listed for the 1.6 litre 16-valve C16XE, X16XE, X16XEL and Y16XE engines in the survey below, at Opel and Vauxhall. For any other vehicle, find the engine code first before placing an order.

Why switch to a reinforced gasket?

When the standard gasket is no longer enough, the reinforced gasket replaces it: at higher combustion pressure it keeps its geometry instead of sagging.

Push an engine harder, with more boost, a higher compression ratio or a thorough build, and the head gasket is the first top-end part to give up. A reinforced gasket avoids the leak and the cylinder head removal that goes with it, a job that costs far more than the part.