Cometic MLS Head Gasket for B18A B18B Integra

Cometic MLS Head Gasket for B18A and B18B Integra

The factory composite head gasket on a B18 was fine for stock power, but once you add boost, nitrous, or serious compression, it becomes the weak link that lets go and pushes coolant or loses a cylinder. This Cometic MLS gasket is the fix. It is built from three layers of stainless steel that clamp down and seal under the kind of cylinder pressure that kills a stock gasket, and it is the standard sealing upgrade for any B18A or B18B build that is making real power. If you are running head studs and chasing boost, this is the gasket that belongs under the head.

MLS stands for multi-layer steel, and the construction is the whole point. The two embossed outer layers are coated on both sides with Viton, a fluoroelastomer that seals against your head and block surfaces and takes heat up to 482 degrees F. The uncoated stainless center shim sets the thickness. There is no sealant required, the gasket seals through clamp load and the geometry of the embossing, and because that clamp load distributes evenly, there is no re-torque needed after install and minimal bore distortion. Stainless also rebounds and resists corrosion, so it holds its seal through heat cycle after heat cycle instead of degrading like a composite gasket.

Pick your thickness, and know it changes your compression

This gasket comes in two thicknesses, and the number you pick is the compressed operating thickness, so it directly affects your compression ratio and your piston-to-valve clearance. A thinner gasket raises compression and shrinks the deck gap, a thicker one lowers compression and opens the gap up. The right choice depends on your block deck height, how much has been milled off the head, and your compression target, so measure and calculate rather than guessing.

Many boosted builders run a thicker gasket to drop static compression and add a margin of safety on cylinder pressure. Naturally aspirated and high-compression builds often want the thinner one. If you are unsure which fits your combination, our staff can walk you through it before you order.

Specs

Fitment

This gasket fits the DOHC non-VTEC B18 engines at up to an 81.5mm bore. Confirm your engine and bore before ordering.

This is the non-VTEC B18 gasket at 81.5mm bore. It does not fit the B18C VTEC (GS-R or Type R), and it does not fit an LS/VTEC or B20/VTEC combination, those use a different bore and a different gasket. If you are running a VTEC head on a non-VTEC block, ask us before ordering so you get the right part.

What to know before you buy

Surface finish matters with an MLS gasket, so get this right or the best gasket in the world will still weep. MLS gaskets want a smooth, flat deck and head surface, smoother than an old composite gasket needed. If your deck or head has been resurfaced, make sure it was finished to an MLS-appropriate smoothness, and check both surfaces for flatness before assembly. A clean, flat, smooth surface is what lets the Viton do its job.

Match the thickness to your actual build, since this is the number that determines your final compression and clearances. Have your block deck height and any head milling measured, then pick the thickness that lands your compression where you want it. This is worth doing on paper before you order, especially on a boosted or high-compression motor where piston-to-valve clearance is tight.

Torque the head properly, and this is where it pays to have your fasteners sorted. Follow the correct torque sequence and spec for your studs or bolts, because even clamp load is what makes an MLS gasket seal. If you are building for boost, this gasket pairs naturally with a quality head stud kit, the studs give you the consistent, high clamp load that lets the MLS gasket hold cylinder pressure. Do the gasket, the surface prep, and the studs together and the head seal is not something you will think about again.