Reinforced head gasket Opel 2.0 16V X20XEV Z20LET Z20LEH

The Opel engines covered

The Opel petrol engines X20XEV (2.0 litre, 136 hp, naturally aspirated) and Z20LET and Z20LEH (2.0 litre turbo, 190 to 240 hp) are sixteen-valve four-cylinder units. They power the Opel Vectra A and B, Omega B, Calibra, Astra F, G and H, Zafira A and B and Speedster models in the compatibility table below.

These engines take two original gaskets: 09 118 313 for the X20XEV, and 6 07 442 for the Z20LET and Z20LEH. Opel publishes neither their bore, nor their thickness, nor their construction. They are sized for the standard combustion pressure: when it rises, the clamping load fades, the cylinder head lifts off the block and coolant finds its way into a cylinder.

Reinforced cylinder head gaskets

The fasteners that clamp the head to the block provide half of the sealing by themselves: the gasket never works alone. A composite gasket is crushed for good from 100 N/mm², while the 301 stainless steel of the MLS gasket takes 517 N/mm², five times more, and regains its shape after every combustion.

This page brings together seven part numbers from Athena, an Italian maker of racing gaskets, for a single construction: the multi-layer steel MLS. The bores run from 87.5 to 88.5 mm, with thicknesses of 1.0, 1.15, 1.3 and 1.9 mm. 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 is the space the gasket leaves free above each cylinder. It adds to the combustion chamber and lowers the compression ratio; at the same bore, the thicker the gasket, the lower the ratio.

Preparation and fitting

Before refitting, check the flatness of the head and block with a straightedge, then have them resurfaced if needed. The Athena gasket is supplied already coated: no sealant should be added.

Technical guide

The construction offered

Athena MLS Two to five AISI 301 stainless steel sheets, laser cut, stamped and riveted together. Around each cylinder, a folded sheet called the Gas Stopper concentrates the clamping force on the combustion chamber, while beads keep the water and oil passages apart. Two coatings cover the outer faces: the first withstands high temperatures and absorbs small flatness errors in the block and head, the second, in silicone, prevents the gasket from sticking when it is removed. It is Athena's all-steel solution, from a prepared naturally aspirated engine up to a turbo at moderate boost.

Choosing bore and thickness

Gasket bore. The Athena MLS is offered in 87.5 mm (338058R, 338060R, 338062R and 338260R), 88 mm (338459R) and 88.5 mm (338059R and 338061R).

Thickness. The thickness of the original gasket is not given by Opel. A thicker gasket enlarges the combustion chamber and lowers the compression ratio; a thinner one reduces it and raises the ratio.

As Opel does not publish the original thickness, use a dial gauge to measure how far the pistons protrude above the block face, particularly if you are considering 1.0 mm or 1.15 mm: it gives the space left between piston and head.

The brand

Athena S.p.A. is an Italian company that designs gaskets and engine parts. Its head office and main factory are in Alonte, in the Veneto region, and the group has further sites in Spain, the United States, Brazil and India. Some car makers fit its multi-layer gaskets as original equipment, and the competition range is designed and built entirely in Italy.

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 original gasket, which Opel does not publish 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: 09 118 313 and 6 07 442.

Important: the part numbers on this page fit only the engines X20XEV, Z20LET and Z20LEH: check your vehicle's engine code before ordering.

Why switch to a reinforced gasket?

When the original gasket reaches its limits, the reinforced gasket takes over: under higher combustion pressure, it keeps its thickness and shape without collapsing.

Turbo, supercharger or raised compression ratio: the more power climbs, the more the head gasket becomes the weak point of the top end. The reinforced gasket prevents the leak, and the head removal that goes with it, which costs far more than the gasket.