{"product_id":"cometic-mls-head-gasket-77mm-bore-030-for-honda-civiccrx-d15d16","title":"Cometic MLS 77mm Head Gasket for Honda Civic\/CRX D15 \u0026 D16","description":"\u003cul\u003e\n\u003cli\u003eConstructed from three layers of stainless steel for enhanced strength \u003c\/li\u003e\n\u003cli\u003eViton-coated outer layers for high-temperature and chemical resistance \u003c\/li\u003e\n\u003cli\u003eUncoated stainless steel shim layer for various thickness options \u003c\/li\u003e\n\u003cli\u003eNo additional sealants or re-torquing required \u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c!-- split --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli\u003e\u003ca class=\"active\" href=\"#Description\"\u003eDescription\u003c\/a\u003e\u003c\/li\u003e\n \u003cli\u003e\u003ca href=\"#VehicleFitment\"\u003eVehicle Fitment\u003c\/a\u003e\u003c\/li\u003e  \u003cli\u003e\u003ca href=\"#TechnicalData\"\u003eTechnical Data\u003c\/a\u003e\u003c\/li\u003e   \u003cli\u003e\u003ca href=\"#Included\"\u003eIncluded\u003c\/a\u003e\u003c\/li\u003e  \u003cli\u003e\u003ca href=\"#InstallGuide\"\u003eInstall Guide\u003c\/a\u003e\u003c\/li\u003e \u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\n\n\u003cli class=\"active\" id=\"Description\"\u003e\n\u003ch3\u003eCometic MLS 77mm Bore Head Gasket for Honda Civic \/ CRX SOHC D15 and D16\u003c\/h3\u003e\n\u003cp\u003eBore out a D-series to fit bigger pistons and the factory head gasket stops fitting. A stock D15 or D16 runs a 75mm bore. Go to 76mm or 76.5mm, and the edge of a stock-bore gasket hangs into the cylinder. That puts the gasket right in the flame on every combustion stroke, and it'll burn through. An overbored engine needs a gasket with a bore that's bigger than the new cylinders. That's what this Cometic gasket is for: a 77mm bore that clears overbored D15 and D16 blocks.\u003c\/p\u003e\n\u003cp\u003eIt's also an MLS gasket, made from stainless steel layers instead of a composite sheet. If you're overboring for more displacement, you're likely adding compression, a cam, or boost too, and all of that raises cylinder pressure. MLS holds its seal where a composite gasket would start to fail. Building a stock-bore D16? Use a gasket sized for 75mm. This one's for blocks that have been bored out.\u003c\/p\u003e\n\u003ch4\u003eSizing the Bore Right\u003c\/h4\u003e\n\u003cp\u003eThe gasket's bore has to be bigger than your cylinders, by enough that the gasket edge stays out of the flame. It shouldn't be so much bigger that you lose sealing surface or quench area around the cylinder for no reason. A 77mm gasket fits blocks bored up to just under 77mm, like a 76mm or 76.5mm overbore. Measure your finished bore before you order. Don't go by the piston box. Your machine shop's final number is the one that matters.\u003c\/p\u003e\n\u003ch4\u003eThree Layers of Stainless\u003c\/h4\u003e\n\u003cp\u003eThe two outer layers are stainless steel embossed with raised beads around each cylinder and passage. When you torque the head down, those beads compress like springs and keep pushing back against the head and block. That's how the seal stays tight as the aluminum grows and shrinks with heat. A Viton coating on the outer layers, a fluoroelastomer rubber rated to 482°F (250°C), fills in tiny surface flaws. The plain stainless center layer sets the thickness, .030in on this one. MLS gaskets clamp evenly across the whole surface, so the cylinders stay rounder once the head's torqued down. The gasket doesn't need to be re-torqued after the first heat cycle, either.\u003c\/p\u003e\n\u003ch4\u003eInstall Notes\u003c\/h4\u003e\n\u003cp\u003eAn MLS gasket needs flat, smooth surfaces to seal against. Since the block's been bored anyway, have the shop deck it and check the head for flatness while they're at it. Get both surfaces to Cometic's MLS finish spec. Clean everything down to bare metal, install the gasket dry, and torque the head in sequence to spec. Factor the .030in thickness into your compression ratio math along with your pistons. For a boosted build, use head studs instead of the factory bolts.\u003c\/p\u003e\n\u003ch4\u003eFitment\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eHonda Civic and CRX with SOHC D15 or D16 engines - confirm your exact engine code before ordering\u003c\/li\u003e\n\u003cli\u003e77mm gasket bore: for blocks overbored to just under 77mm\u003c\/li\u003e\n\u003cli\u003e.030in compressed thickness\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n \n\u003cli id=\"VehicleFitment\"\u003e\n \u003cp\u003e   Honda Civic SOHC D15\/D16   Honda CRX SOHC D15\/D16\u003c\/p\u003e \n\u003c\/li\u003e\n\n\n\n\n\u003cli id=\"TechnicalData\"\u003e\n\u003cp\u003eMaterial: Multi-Layer Steel (MLS), Coating: Viton, Bore Size: 77mm, Thickness: .030 inches, Temperature Resistance: Up to 250°C (482°F)\u003c\/p\u003e\n\u003c\/li\u003e\n\n\n\n \n\u003cli id=\"Included\"\u003e\n\n\u003c\/li\u003e\n\n\n\n\n\n\n\n\n\n\n\n\u003cli id=\"InstallGuide\"\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n","brand":"Cometic Gasket","offers":[{"title":"Default Title","offer_id":69834029793314,"sku":"COG-C4196-030","price":96.52,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/2218\/5701\/files\/COG-C4196-030_1.jpg?v=1794602666","url":"https:\/\/www.hybrid-racing.com\/products\/cometic-mls-head-gasket-77mm-bore-030-for-honda-civiccrx-d15d16","provider":"Hybrid Racing","version":"1.0","type":"link"}