Reinforced cylinder head gasket Nissan L24 L24S L24E L26

The Nissan engines covered

The Nissan petrol engines L24, L24S, L24E and L26, inline six-cylinders of 2.4 and 2.6 litres, power the Nissan 240Z, 260Z, Skyline, Laurel, Cedric, Gloria, Maxima, 810 and Bluebird models described below.

Two original gaskets exist: 10044-N4200 for the L24, L24S and L26 engines, with an 85 mm bore, and 11044-27L01 for the L24E, with an 84.5 mm bore. Nissan publishes neither their thickness nor their construction. They are sized for standard pressure: as soon as it rises, the clamping relaxes, the head lifts off and coolant reaches a cylinder.

Reinforced cylinder head gaskets

The head gasket does not seal on its own: the fasteners that clamp the head to the block take part as much as it does. Beyond 100 N/mm², a composite gasket sags for good; the 301 stainless steel of MLS gaskets withstands 517 N/mm², 5 times more, and regains its shape at every combustion.

This page brings together the part numbers of Cometic, an American maker of competition gaskets, around a single construction: the multi-layer steel MLS. The gaskets exist in an 85 mm bore, with two part numbers in 87 mm, and in thicknesses from 0.69 to 3.56 mm, enough to adjust the compression ratio without touching the pistons or the cylinder head. 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 empty space it leaves above each cylinder. It adds to the combustion chamber and lowers the compression ratio, the more so as it is large. Compare these values only between gaskets of the same bore.

Preparation and fitting

Before fitting, check the flatness of the head and block faces with a straight edge, then have them machined if needed. Apply no sealing paste: Cometic gaskets are supplied coated.

Technical guide

The construction offered

MLS Cometic Stainless steel layers, stamped and then joined by rivets. The outer layers carry active beads around each cylinder and each fluid passage. Measured tightening is enough to seal and the bore barely distorts. This versatile construction suits everything from the prepared naturally aspirated engine to moderate boost.

Choosing bore and thickness

Gasket bore. Cometic MLS is offered in 85 mm (C4579) and, on two part numbers, in 87 mm (H3528).

Thickness. Nissan publishes no thickness for the original gaskets of these engines. A thicker gasket enlarges the combustion chamber and lowers the compression ratio; a thinner one reduces it and raises the ratio.

If you choose a thickness below the original, first measure with a dial gauge the height of the pistons relative to the block deck: that figure sets the clearance left between piston and head.

The brand

Cometic Gasket, Inc., an American company founded in 1989 in Concord, Ohio, designs engine gaskets and sealing solutions. Its specialty is the made-to-measure gasket, cut to the bore and thickness wanted. All of its manufacturing stays in the United States, with American 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 bore of the original gasket, 85 mm or 84.5 mm depending on the engine 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: 10044-N4200 and 11044-27L01.

Important: the part numbers on this page apply to the Nissan engines L24, L24S, L24E and L26: identify the engine code of your car, then the bore required, before ordering.

Why switch to a reinforced gasket?

Where the original gasket reaches its limit, the reinforced gasket takes over: under higher combustion pressure it keeps its shape and does not crush.

With a turbo, a supercharger or a raised compression ratio, the head takes heavier loads and the gasket becomes the most stressed part of the top end. A reinforced gasket rules out the gas or coolant leak and the head removal that follows, with the car off the road.