Reinforced head gasket Alfa Romeo 1.5 1.6 AR30124 AR30146 AR30504 AR30514 AR30520 AR30588 AR30734 AR30751 AR33201

The Alfa Romeo engines covered

The 1.5 litre (AR30124, AR30143, AR30146, AR30504, AR30508, AR30514, AR30520, AR30588, AR30734, AR30750, AR30751) and 1.6 litre (AR33201) eight-valve petrol engines power the Alfasud, Sprint, 33, 145 and 146 models listed below.

The original gasket for these engines carries the manufacturer part numbers 60505485, 60505488, 60591810 and 60591811. The manufacturer publishes neither its bore, nor its construction, nor its thickness. It is sized for standard combustion pressure: once that rises, the clamping force fades, the cylinder head lifts and coolant works its way into a cylinder.

Reinforced cylinder head gaskets

The seal does not rest on the gasket alone: it also depends on the bolts or studs that clamp the cylinder head to the block. With the O-Ring each element has its job: the stainless ring closes the combustion chamber by itself, the sheet handles the water and oil passages, and the block needs no machining.

This page covers the part number from Athena, an Italian maker of competition gaskets, in a single construction: the O-Ring, a steel sheet clad in aramid fibre and encircled by a stainless steel ring. Its bore is 85.4 mm and its thickness 1.50 mm. Practical rule: pick a gasket bore at least 0.5 mm larger than the cylinder bore. The part number is sold individually, with one gasket per engine.

Technical specifications

A gasket's volume is the space it keeps open above each cylinder. It adds to the combustion chamber and so lowers the compression ratio; only gaskets of the same bore can be compared.

Preparation and fitting

Before fitting, run a straight edge over the cylinder head and the block to check their flatness, and have the faces machined if needed. Athena supplies the gasket ready to fit: do not apply any sealant.

Technical guide

The construction offered

Athena O-Ring A steel sheet covered with asbestos-free aramid fibre, in which each cylinder is encircled by a stainless steel compression ring. The ring carries the clamping load onto a narrow band, exactly where the seal is decided, while a silicone bead isolates the water and oil circuits. Across the whole range, it is the construction that withstands high pressures best.

Choosing bore and thickness

Gasket bore. The Athena O-Ring is offered in 85.4 mm (330008R), in that bore only.

Thickness. The manufacturer gives no thickness figure for the original gasket. A thicker gasket enlarges the combustion chamber and lowers the compression ratio; a thinner one reduces it and raises the ratio.

Since the original thickness is not published, use a dial gauge to measure how far the pistons stand above the block, especially if the removed gasket is thicker than 1.50 mm: that figure sets the clearance left between piston and cylinder head.

The brand

Athena S.p.A., an Italian maker of gaskets and engine components, has its head office and largest factory in Alonte, in the Veneto. The group also operates sites in Spain, the United States, Brazil and India. Its multi-layer gaskets are fitted by car makers as original equipment, and its entire competition range is designed and built 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 85.4 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: 60505485, 60505488, 60591810 and 60591811.

Important: the part number on this page fits only the Alfa Romeo engines listed in the compatibility table: 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 holds its shape and does not collapse.

As soon as power goes up, through a larger turbo, a more aggressive map or a raised compression ratio, the head gasket is the first part of the top end to fail. A reinforced gasket prevents the leak and the cylinder head removal that goes with it.