The Cometic MLS (Multi Layer Steel) gasket is comprised of three layers of Stainless Steel.
Cometic uses Stainless Steel for increased strength, it\'s ability to rebound and corrosion resistance. The outer layers of the gasket are embossed and coated on both sides with a flouroelastomer rubber based materioal (Viton) designed to meet the demands of a variety of harsh sealing environments, load conditions and surface finishes. The Viton Coating is heat resistant to 250 degrees Celcius or 482 degrees farenheit. The center or shim layer of the gasket is comprised of an uncoated Stainless Steel layer, which can be varied to accommodate multiple thickness requirements.
The MLS gasket is ideal for both aluminum heads to cast iron blocks and aluminum heads to aluminum blocks. The composition of MLS will also withstand the shearing forces created by aluminum heads on cast iron blocks. No re-torque is necessary. By design the MLS gasket promotes an even torque load across the sealing surface allowing for measurable reduced bore distortion.
We stock Cometic MLS Head Gaskets in a variety of bore sizes as an option below including 88mm, 89mm, & 90mm. We recommend using a size slightly larger (0.5-1.0mm) than the finished cylinder bore. For instance if using 88mm (1 mm or .040") OS pistons we use a 89 mm Cometic gasket.
We also stock these gaskets in different thicknesses. Including .045" (stock), .051" (6 thousanths thicker), and even thicker sizes are available for custom order. If rebuilding and your block has been decked and heads have been surfaced with-in Nissan specifications, chances are that around 5-7 thousandths of material has been removed between the block and the heads (8 thousandths being the factory specified limit). In this case the .051" thickness (6 thousandths thicker) will closely compensate for the amount of material removed. Decking block and surfacing heads (especially past factory specifications) without increasing headgasket thickness results in higher compression ratios, affects timing due to distances between crank and cam timing sprockets changing, as well as can cause problems with valve to piston clearances in extreme circumstances.
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