{"product_id":"cometic-86mm-k20-mls-head-gasket-c4300","title":"Cometic 86mm K20 MLS Head Gasket C4300","description":"\u003cul\u003e\n\u003cli\u003e86mm bore, K20A\/K20A2\/A3\/Z1 \u003c\/li\u003e\n\u003cli\u003e3-layer stainless with Viton coating \u003c\/li\u003e\n\u003cli\u003eCompressed thickness .040 in, .045 in \u003c\/li\u003e\n\u003cli\u003eWithstands up to 250°C \u003c\/li\u003e\n\u003cli\u003e2002-2006 Acura RSX, Civic Si \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=\"#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 86mm K20 MLS Head Gasket - Part #C4300-040 \/ C4300-045\u003c\/h3\u003e\n\u003cp\u003eThis is the head gasket for a K20 at its stock 86mm bore: an RSX, an EP3, or a K20A2\/A3\/Z1 swap that hasn't been bored or sleeved. Cometic's 3-layer MLS in .040 or .045 compressed, which is what you reach for when the block has been decked and you need to put the compression and valve clearance back where they belong.\u003c\/p\u003e\n\u003ch3\u003eWhat It Is and Why It Works\u003c\/h3\u003e\n\u003cp\u003eCometic's MLS gasket is three layers of stainless steel: two embossed outer layers coated in a Viton fluoroelastomer that seals against the block and head, and a center shim that sets the compressed thickness. The Viton handles 250 C, the stainless springs back after every heat cycle instead of taking a set, and the layered design tolerates the slight movement between an aluminum head and block that kills a composite gasket. It's the same construction Honda uses from the factory, done with more clamp margin.\u003c\/p\u003e\n\u003cp\u003eThickness is how you set compression and piston-to-valve clearance after a deck cut or a piston change. Thicker gasket, lower static compression, more clearance; thinner, the reverse. Cometic sells the same gasket in several thicknesses for that reason, and the bore has to clear your actual cylinder bore, not the one the engine left the factory with.\u003c\/p\u003e\n\u003ch3\u003eSpecs\u003c\/h3\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePart number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eC4300-040, C4300-045\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMaterial\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eMLS, 3-layer stainless with Viton coating\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBore\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e86mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eCompressed thickness\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e.040 in, .045 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eEngines\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eK20A, K20A2, K20A3, K20Z1 (stock bore)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eIncluded\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e1 head gasket\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003ch3\u003eFitment\u003c\/h3\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eVehicle\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003eEngine\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2002-2006 Acura RSX Base, Type-S\u003c\/td\u003e\n\u003ctd\u003eK20A3, K20A2, K20Z1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2002-2005 Honda Civic Si\u003c\/td\u003e\n\u003ctd\u003eK20A3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eK-swaps\u003c\/td\u003e\n\u003ctd\u003eK20A, K20A2, K20A3, K20Z1 at stock 86mm bore\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cp\u003e86mm is the stock K20 bore. The K24 is 87mm from the factory and does not take this gasket; use the 87mm C4311. The K20Z3 (06-11 Civic Si) uses a different coolant passage layout and takes Cometic C4561 instead.\u003c\/p\u003e\n\u003ch3\u003eWhat to Know Before You Buy\u003c\/h3\u003e\n\u003cp\u003eSurface finish matters more than anything else. Cometic wants the block and head decked to 50 RA or smoother; an MLS gasket on a rough or corroded deck will weep coolant no matter how it's torqued. Have the head checked for flatness and skimmed if it's been overheated.\u003c\/p\u003e\n\u003cp\u003ePick thickness by what you're correcting. Stock K20 gaskets are roughly .030 compressed; .040 drops static compression about a quarter point on a stock K20A2 and buys clearance after a light deck cut, .045 a bit more. If you haven't cut anything and aren't chasing clearance, the .030 C4300-030 is closer to stock.\u003c\/p\u003e\n\u003cp\u003eMeasure the bore. A block that's been honed a few thou is fine; one that's been bored to 87 needs the C4311.\u003c\/p\u003e\n\n\u003c\/li\u003e\n\n \n\u003cli id=\"VehicleFitment\"\u003e\n \u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eVehicle\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003eEngine\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2002-2006 Acura RSX Base, Type-S\u003c\/td\u003e\n\u003ctd\u003eK20A3, K20A2, K20Z1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2002-2005 Honda Civic Si\u003c\/td\u003e\n\u003ctd\u003eK20A3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eK-swaps\u003c\/td\u003e\n\u003ctd\u003eK20A, K20A2, K20A3, K20Z1 at stock 86mm bore\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cp\u003e86mm is the stock K20 bore. The K24 is 87mm from the factory and does not take this gasket; use the 87mm C4311. The K20Z3 (06-11 Civic Si) uses a different coolant passage layout and takes Cometic C4561 instead.\u003c\/p\u003e \n\u003c\/li\u003e\n\n\n\n\n\u003cli id=\"TechnicalData\"\u003e\n\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePart number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eC4300-040, C4300-045\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMaterial\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eMLS, 3-layer stainless with Viton coating\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBore\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e86mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eCompressed thickness\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e.040 in, .045 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eEngines\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eK20A, K20A2, K20A3, K20Z1 (stock bore)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eIncluded\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e1 head gasket\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePackaged size \/ weight\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e17.7 x 8.2 x 0.01 in, 0.8 lb (per PIM)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\u003cli id=\"InstallGuide\"\u003e\n\n\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n","brand":"Cometic Gasket","offers":[{"title":".040 in","offer_id":46630554304546,"sku":"COG-C4300-040","price":96.52,"currency_code":"USD","in_stock":false},{"title":".045 in","offer_id":46630554337314,"sku":"COG-C4300-045","price":96.52,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/2218\/5701\/files\/17587546.jpg?v=1787952319","url":"https:\/\/www.hybrid-racing.com\/products\/cometic-86mm-k20-mls-head-gasket-c4300","provider":"Hybrid Racing","version":"1.0","type":"link"}