Reinforced head gasket Lancia Fulvia Coupé 1.6 838A.100

The Lancia engines covered

The 838 A.100 petrol engine (1.6 litres, 1,584 cc), a four-cylinder, powers the Lancia Fulvia Coupé 1.6 listed below.

Nothing is published about the original gasket of this engine: no part number, no bore, no construction and no thickness. It is sized for standard combustion pressure; as soon as that pressure rises, the clamping of the head weakens, 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 tighten the head onto the block count just as much. The CFM-20, with its galvanized steel core and asbestos-free soft compound, makes up for small irregularities in the gasket faces.

This page offers three part numbers from the American maker Cometic, a specialist in racing gaskets, in a single construction: CFM-20. Their bores are 83 and 84 mm and their thicknesses 1.09 and 1.50 mm. Each part number is sold individually: one gasket per engine.

Technical specifications

A gasket's volume is the space it leaves free above each cylinder: it adds to the combustion chamber and reduces the compression ratio. Only gaskets of the same bore can be compared.

Preparation and fitting

Before fitting, lay a straight edge across the head and the block to check their flatness, and have whichever is warped resurfaced. Cometic checks each of its CFM-20 gaskets before shipping.

Technical guide

The construction offered

Choosing bore and thickness

Gasket bore. The Cometic CFM-20 gasket is offered in 83 mm (H2687043F) and in 84 mm (H2687SP1043F and H2687SP5059F).

Thickness. No thickness is given for the original gasket of this engine: the dimension of the removed gasket serves as the reference. A thicker gasket enlarges the combustion chamber and lowers the compression ratio; a thinner one reduces it and raises the ratio.

As no original thickness is published, measure with a dial gauge how far the pistons protrude above the block's gasket face, above all before choosing the 1.09 mm gasket: this shows the clearance left between piston and head.

The brand

Cometic Gasket, Inc. is an American company, founded in 1989 in Concord (Ohio), that makes gaskets and sealing solutions for engines. It owes its reputation to the custom-cut gasket, made to the bore and thickness requested and produced 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 83 and 84 mm bores of the gaskets 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: not published by the manufacturer.

Important: the part numbers on this page suit the Lancia 838 A.100 engine of 1.6 litres (Fulvia Coupé 1.6): check your vehicle's engine code before ordering. The gasket chosen must have a bore at least 0.5 mm larger than that of the cylinders.

Why switch to a reinforced gasket?

When the original gasket is no longer enough, this CFM-20 gasket takes over: the steel core keeps its shape under combustion pressure, and the soft compound on both faces follows the small flaws of the head and block.

On a pushed engine, the head gasket is often the first part to give way, at the top of the engine. The reinforced gasket prevents the leak, whereas the head removal that would follow costs far more than the gasket itself.