Reinforced head gasket Nissan Sunny Cherry Datsun 120 A12 A15

The Nissan engines covered

The A12 (1.2 litre) and A15 (1.5 litre) four-cylinder petrol engines power the Nissan Sunny, Cherry, Pulsar, Datsun 120 and the other models listed below.

Two original gaskets exist: the 11044-H1000 (A12) and the 11044-H7200 (A15). Nissan publishes neither their bore, nor their construction, nor their thickness. 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

The gasket does not seal on its own: sealing also depends on the fasteners that clamp the head against the block. Copper of 99.9% purity resists corrosion, deforms without breaking and conducts heat well, without becoming fragile under 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 79 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

The volume of a gasket is the space it leaves open above each cylinder. It joins the combustion chamber and lowers the compression ratio; only gaskets of the same bore can be compared.

Preparation and fitting

Before fitting, check the flatness of the head and block with a straight edge, and have them resurfaced if need be. 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 79 mm (H3103063C), with no other bore.

Thickness. Nissan 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 measure how far the pistons stand above the block face, especially if the removed gasket is thinner than 1.60 mm: that measurement shows the clearance left between piston and head.

The brand

Cometic Gasket, Inc. is an American maker of gaskets and sealing solutions for engines, founded in 1989 in Concord, Ohio. It owes its reputation to the made-to-measure gasket, cut to the bore and thickness wanted. All manufacturing stays in the United States, with 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 79 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: 11044-H1000 and 11044-H7200.

Important: the part number on this page suits the A12 and A15 engines: check your vehicle's engine code before ordering.

Why switch to a reinforced gasket?

When the original gasket reaches the end of its capacity, this copper gasket takes over: pure copper is ductile and does not turn brittle when hot, which keeps the seal between head and block.

A turbo, a supercharger or a higher compression ratio test the head gasket first, the weak link of the top end. Choosing a reinforced gasket means preventing the leak and the head removal that follows from it, a job far dearer than the gasket itself.