Reinforced head gasket Alfa Romeo 75 155 164 2.0 Twin Spark AR06166 AR06224 AR06416 AR06420 AR64103 AR67201 AR67202

The Alfa Romeo engines covered

The 2.0 litre Twin Spark petrol engines AR06166, AR06224, AR06416, AR06420, AR64103, AR67201 and AR67202, four-cylinder eight-valve units, power the Alfa Romeo 75, 155 and 164 listed below.

Two original gaskets exist: the 195510150800 (AR06166, AR06224, AR06420) and the 60552577 (AR64103, AR67201, AR67202). Alfa Romeo publishes neither their bore, nor their construction, nor their thickness, and gives no original part number for the AR06416. They are calculated for the original combustion pressure: if it rises, the clamping load eases, the head lifts and coolant passes into a cylinder.

Reinforced cylinder head gaskets

Sealing does not depend on the gasket alone: the fasteners that clamp the head onto the block contribute just as much. Pure copper at 99.9% resists corrosion, deforms without breaking and carries heat away well, without growing brittle with temperature.

This page describes the part number from the American maker Cometic, a specialist in racing gaskets, in a single construction: copper. Its bore is 85 mm and its thickness 1.60 mm. By convention, the gasket bore is at least 0.5 mm larger than that of the cylinders. It is sold individually: one gasket per engine.

Technical specifications

A gasket's volume is the space it leaves free above each cylinder. This space adds to the combustion chamber and lowers the compression ratio; only gaskets of the same bore should be compared.

Preparation and fitting

Before fitting, check the flatness of the head and block with a straight edge, and have either resurfaced if necessary. Cometic checks the flatness of each of its copper gaskets.

Technical guide

The construction offered

Choosing bore and thickness

Gasket bore. The Cometic copper gasket is offered in 85 mm (H1995SP2063C), with no other bore.

Thickness. Alfa Romeo gives no thickness for the original gaskets. 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 find how far the pistons protrude above the block's gasket face, especially if the removed gasket is thinner than 1.60 mm: this reading gives the clearance left between piston and head.

The brand

Cometic Gasket, Inc. is an American maker of gaskets and sealing solutions for engines, created in 1989 in Concord, Ohio. Its reputation comes from the made-to-measure gasket, cut to the bore and thickness required. Everything is made 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 85 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: 195510150800 and 60552577.

Important: the part number on this page suits the AR06166, AR06224, AR06416, AR06420, AR64103, AR67201 and AR67202 engines: check your vehicle's engine code before ordering.

Why switch to a reinforced gasket?

When the original gasket reaches its limit, this copper gasket takes over: pure copper stays ductile and does not turn brittle when hot, which preserves the seal between head and block.

Turbo, supercharger or a raised compression ratio: the head gasket is the first part to give way, the weak point of the top end. A reinforced gasket prevents the leak, and the head removal that goes with it costs far more than the gasket.