{"product_id":"supertech-valves-black-nitride-d-series-non-vtec","title":"Supertech Black Nitride Valves for Honda D-Series NON-VTEC","description":"Supertech black nitride exhaust and intake valves for NON-VTEC D-Series engines. These valves are available in various sizes to match your head diameter. Sold as a set of 8 or individually as needed. Please do all your research and consult your engine builder if necessary! Black nitride valves are made from one piece forged stainless steel then go through a special hardening process to lessen the friction between the valve and guide. \u003cbr\u003e\u003cbr\u003e\u003cspan style=\"color: #ff2a00;\"\u003eVehicle Fitment:\u003c\/span\u003e\u003cbr\u003e Honda Civic, CRX, NON-VTEC SOHC\u003cbr\u003e D15B, D16A6\u003cbr\u003e \u003cbr\u003e\n\u003cdiv style=\"overflow-x: auto;\"\u003e\n\u003ctable border=\"0\" cellpadding=\"0\" cellspacing=\"0\"\u003e\n\u003ctbody\u003e\n\u003ctr bgcolor=\"2d2d2d\"\u003e\n\u003ctd style=\"color: #ffffff;\"\u003eFitment:\u003c\/td\u003e\n\u003ctd style=\"color: #ffffff;\"\u003eSize:\u003c\/td\u003e\n\u003ctd style=\"color: #ffffff;\"\u003eIncludes:\u003c\/td\u003e\n\u003ctd style=\"color: #ffffff;\"\u003ePart Numbers:\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr bgcolor=\"404040\"\u003e\n\u003ctd style=\"color: #ffffff;\" rowspan=\"2\"\u003eExhaust\u003c\/td\u003e\n\u003ctd style=\"color: #ffffff;\" rowspan=\"2\"\u003eStandard 25.0mm\u003cbr\u003e • Stem Diameter 5.45mm\u003cbr\u003e • Length 118.75mm\u003cbr\u003e\n\u003c\/td\u003e\n\u003ctd style=\"color: #ffffff;\"\u003e8 Valves\u003c\/td\u003e\n\u003ctd style=\"color: #ffffff;\"\u003eHEVN-1003-8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr bgcolor=\"404040\"\u003e\n\u003ctd style=\"color: #ffffff;\"\u003e1 Valve\u003c\/td\u003e\n\u003ctd style=\"color: #ffffff;\"\u003eHEVN-1003-1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr bgcolor=\"2d2d2d\"\u003e\n\u003ctd style=\"color: #ffffff;\" rowspan=\"2\"\u003eIntake\u003c\/td\u003e\n\u003ctd style=\"color: #ffffff;\" rowspan=\"2\"\u003eStandard 29.0mm\u003cbr\u003e • Stem Diameter 5.48mm\u003cbr\u003e • Length 115.00mm\u003cbr\u003e\n\u003c\/td\u003e\n\u003ctd style=\"color: #ffffff;\"\u003e8 Valves\u003c\/td\u003e\n\u003ctd style=\"color: #ffffff;\"\u003eHIVN-1003-8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr bgcolor=\"2d2d2d\"\u003e\n\u003ctd style=\"color: #ffffff;\"\u003e1 Valve\u003c\/td\u003e\n\u003ctd style=\"color: #ffffff;\"\u003eHIVN-1003-1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\nThe \"Black Nitride\" is a hardening treatment that is applied to the whole valve whereas the chrome coating is only applied to the stem. The microhardness is higher than the stainless steel base material, keeping good ductility beneath the hard nitrided layer. Microhardness is 800HV minimum.\u003cbr\u003e\u003cbr\u003eThe Black Nitride surface finish is smoother than with chromed stems, having less friction between stem and guide. The higher the engine speed the bigger the power loss due to internal engine friction! The Black Nitride reduces this power loss due to less valve-guide friction.\u003cbr\u003e\u003cbr\u003e \u003cspan style=\"color: #ff2a00;\"\u003eNote:\u003c\/span\u003e\u003cbr\u003eImages are for reference. Some Supertech parts have varying part numbers with slashes, dashes, spaces or quantities.\u003cbr\u003e\u003ca style=\"color: #afafaf;\" href=\"https:\/\/stmtuned.com\/collections\/supertech-products\"\u003e\u003cbr\u003e\n\u003cdiv style=\"text-align: center;\"\u003e\u003cspan style=\"font-size: .8em;\"\u003e See more Supertech Parts\u003c\/span\u003e\u003c\/div\u003e\n\u003c\/a\u003e","brand":"Supertech","offers":[{"title":"Exhaust 25.0mm (Set of 8) (HEVN-1003-8)","offer_id":50562321842518,"sku":"SUP-HEVN-1003-8","price":178.51,"currency_code":"EUR","in_stock":true},{"title":"Exhaust 25.0mm (1 Single) (HEVN-1003-1)","offer_id":50562321875286,"sku":"SUP-HEVN-1003-1","price":26.28,"currency_code":"EUR","in_stock":true},{"title":"Intake 29.0mm (Set of 8) (HIVN-1003-8)","offer_id":50562321908054,"sku":"SUP-HIVN-1003-8","price":178.51,"currency_code":"EUR","in_stock":true},{"title":"Intake 29.0mm (1 Single) (HIVN-1003-1)","offer_id":50562321940822,"sku":"SUP-HIVN-1003-1","price":26.28,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0817\/9531\/8102\/files\/supertech-valves-black-nitride-d-series-non-vtec-1.jpg?v=1749201297","url":"https:\/\/www.speed-addicts.com\/en\/products\/supertech-valves-black-nitride-d-series-non-vtec","provider":"Speed Addicts","version":"1.0","type":"link"}