{"product_id":"keith-black-pistons-dome-top-pistons-kb297-std-for-big-twin-1978-1984","title":"Keith Black Pistons Dome Top Pistons KB297.STD for Big Twin 1978-1984","description":"\u003cp style=\"margin:1em 0\"\u003eThese standard dome top pistons are crafted from high-grade hypereutectic alloy featuring a 16% silicon content, engineered specifically for the demands of air-cooled engines. The low thermal expansion rate allows for tighter piston-to-cylinder clearance, maximizing combustion efficiency and overall engine performance.\u003c\/p\u003e\u003cp style=\"margin:1em 0\"\u003eDesigned to deliver an 8.3:1 compression ratio with 117cc head chamber volume, this kit directly replaces OEM # 21990-80 for reliable engine rebuilding and restoration projects.\u003c\/p\u003e\n\u003ch3 style=\"margin:1.25em 0 0.5em\"\u003eKey Features\u003c\/h3\u003e\n\u003ctable class=\"pu-table\" style=\"width:100%;border-collapse:separate;border-spacing:0;border:0;box-shadow:none;outline:none;background:none;table-layout:fixed;margin:0 0 1em\"\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:0;padding:0.4em 0.75em 0.4em 0;opacity:0.65;vertical-align:top;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003eBrand\u003c\/td\u003e\n\u003ctd style=\"border:0;padding:0.4em 0;vertical-align:top;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003eKeith Black Pistons\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:0;padding:0.4em 0.75em 0.4em 0;opacity:0.65;vertical-align:top;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003eManufacturer Part Number\u003c\/td\u003e\n\u003ctd style=\"border:0;padding:0.4em 0;vertical-align:top;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003eKB297.STD\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:0;padding:0.4em 0.75em 0.4em 0;opacity:0.65;vertical-align:top;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003eProduct Type\u003c\/td\u003e\n\u003ctd style=\"border:0;padding:0.4em 0;vertical-align:top;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003eDome Top Pistons\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:0;padding:0.4em 0.75em 0.4em 0;opacity:0.65;vertical-align:top;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003eBore\u003c\/td\u003e\n\u003ctd style=\"border:0;padding:0.4em 0;vertical-align:top;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003e88.8 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:0;padding:0.4em 0.75em 0.4em 0;opacity:0.65;vertical-align:top;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003eStroke\u003c\/td\u003e\n\u003ctd style=\"border:0;padding:0.4em 0;vertical-align:top;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003e108 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:0;padding:0.4em 0.75em 0.4em 0;opacity:0.65;vertical-align:top;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003eMaterial\u003c\/td\u003e\n\u003ctd style=\"border:0;padding:0.4em 0;vertical-align:top;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003eHypereutectic Alloy (16% Silicon Content)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:0;padding:0.4em 0.75em 0.4em 0;opacity:0.65;vertical-align:top;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003eCompression Ratio\u003c\/td\u003e\n\u003ctd style=\"border:0;padding:0.4em 0;vertical-align:top;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003e8.3:1 (with 117cc Chamber Volume)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:0;padding:0.4em 0.75em 0.4em 0;opacity:0.65;vertical-align:top;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003eOEM Replacement\u003c\/td\u003e\n\u003ctd style=\"border:0;padding:0.4em 0;vertical-align:top;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003e21990-80\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:0;padding:0.4em 0.75em 0.4em 0;opacity:0.65;vertical-align:top;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003eEngine Compatibility\u003c\/td\u003e\n\u003ctd style=\"border:0;padding:0.4em 0;vertical-align:top;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003e1340cc Shovelhead\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:0;padding:0.4em 0.75em 0.4em 0;opacity:0.65;vertical-align:top\"\u003eVehicle Fitment\u003c\/td\u003e\n\u003ctd style=\"border:0;padding:0.4em 0;vertical-align:top\"\u003eBig Twin 1978-1984\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003ch3 style=\"margin:1.25em 0 0.5em\"\u003eHighlights\u003c\/h3\u003e\n\u003cul style=\"margin:1em 0\"\u003e\n\u003cli\u003eCast hypereutectic alloy with 16% silicon content\u003c\/li\u003e\n\u003cli\u003eLow thermal expansion rate for tighter operating clearances\u003c\/li\u003e\n\u003cli\u003eEngineered specifically for air-cooled applications\u003c\/li\u003e\n\u003cli\u003e8.3:1 compression ratio with 117cc chamber volume\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"margin:1.25em 0 0.5em\"\u003eCompatibility\u003c\/h3\u003e\n\u003cp style=\"margin:1em 0\"\u003eFits Big Twin 1978-1984 models with 1340cc Shovel engine. Replaces OEM # 21990-80.\u003c\/p\u003e\n\u003ch3 style=\"margin:1.25em 0 0.5em\"\u003eWhat's included\u003c\/h3\u003e\n\u003cul style=\"margin:1em 0\"\u003e\n\u003cli\u003e2 x Hypereutectic Pistons\u003c\/li\u003e\n\u003cli\u003ePiston Rings\u003c\/li\u003e\n\u003cli\u003eWrist Pins\u003c\/li\u003e\n\u003cli\u003eRetaining Clips\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"margin:1.25em 0 0.5em\"\u003eDownloads\u003c\/h3\u003e\n\u003cul style=\"margin:1em 0\"\u003e\u003cli style=\"margin:0 0 0.35em\"\u003e\u003ca href=\"https:\/\/images.rolliesspeedshop.com\/pdf\/KB297.STD.pdf\" target=\"_blank\" rel=\"noopener nofollow\"\u003eDownload Product information ( PDF)\u003c\/a\u003e\u003c\/li\u003e\u003c\/ul\u003e\n\u003ctable class=\"pu-table\" style=\"width:100%;border-collapse:separate;border-spacing:0;border:0;box-shadow:none;outline:none;background:none;table-layout:fixed;margin:0\"\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd style=\"border:0;padding:0\"\u003e\n\u003ch3 style=\"margin:1.25em 0 0.5em\"\u003eFrequently asked questions\u003c\/h3\u003e\n\u003cstyle\u003e.pu-faq[open]\u003esummary .pu-faq-c{transform:rotate(180deg)}\u003c\/style\u003e\n\u003ctable class=\"pu-table\" style=\"width:100%;border-collapse:separate;border-spacing:0;border:0;box-shadow:none;outline:none;background:none;table-layout:fixed;margin:0 0 1em\"\u003e\u003ctbody\u003e\n\u003ctr\u003e\u003ctd style=\"border:0;padding:0;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003e\u003cdetails class=\"pu-faq\" style=\"padding:0.45em 0\"\u003e\u003csummary style=\"cursor:pointer;display:flex;align-items:center;justify-content:space-between;gap:10px;list-style:none\"\u003e\u003cstrong\u003eWhat components are included in this kit?\u003c\/strong\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 24 24\" width=\"18\" height=\"18\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.75\" stroke-linecap=\"round\" stroke-linejoin=\"round\" class=\"pu-faq-c\" style=\"width:1em;height:1em;flex:none;opacity:0.6;transition:transform 0.15s\" aria-hidden=\"true\"\u003e\u003cpath d=\"M6 9l6 6l6 -6\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/summary\u003e\u003cp style=\"margin:0.4em 0 0\"\u003eThe complete kit includes two pistons, rings, wrist pins, and clips.\u003c\/p\u003e\u003c\/details\u003e\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd style=\"border:0;padding:0;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003e\u003cdetails class=\"pu-faq\" style=\"padding:0.45em 0\"\u003e\u003csummary style=\"cursor:pointer;display:flex;align-items:center;justify-content:space-between;gap:10px;list-style:none\"\u003e\u003cstrong\u003eWhat is the compression ratio of these pistons?\u003c\/strong\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 24 24\" width=\"18\" height=\"18\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.75\" stroke-linecap=\"round\" stroke-linejoin=\"round\" class=\"pu-faq-c\" style=\"width:1em;height:1em;flex:none;opacity:0.6;transition:transform 0.15s\" aria-hidden=\"true\"\u003e\u003cpath d=\"M6 9l6 6l6 -6\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/summary\u003e\u003cp style=\"margin:0.4em 0 0\"\u003eThese pistons provide an 8.3:1 compression ratio when paired with a 117cc head chamber volume.\u003c\/p\u003e\u003c\/details\u003e\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd style=\"border:0;padding:0;border-bottom:1px solid rgba(128,128,128,0.16);border-bottom:1px solid color-mix(in srgb,currentColor 12%,transparent)\"\u003e\u003cdetails class=\"pu-faq\" style=\"padding:0.45em 0\"\u003e\u003csummary style=\"cursor:pointer;display:flex;align-items:center;justify-content:space-between;gap:10px;list-style:none\"\u003e\u003cstrong\u003eWhat OEM part number do these pistons replace?\u003c\/strong\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 24 24\" width=\"18\" height=\"18\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.75\" stroke-linecap=\"round\" stroke-linejoin=\"round\" class=\"pu-faq-c\" style=\"width:1em;height:1em;flex:none;opacity:0.6;transition:transform 0.15s\" aria-hidden=\"true\"\u003e\u003cpath d=\"M6 9l6 6l6 -6\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/summary\u003e\u003cp style=\"margin:0.4em 0 0\"\u003eThese pistons directly replace OEM part number 21990-80.\u003c\/p\u003e\u003c\/details\u003e\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd style=\"border:0;padding:0\"\u003e\u003cdetails class=\"pu-faq\" style=\"padding:0.45em 0\"\u003e\u003csummary style=\"cursor:pointer;display:flex;align-items:center;justify-content:space-between;gap:10px;list-style:none\"\u003e\u003cstrong\u003eWhich engines are compatible with this piston kit?\u003c\/strong\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 24 24\" width=\"18\" height=\"18\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"1.75\" stroke-linecap=\"round\" stroke-linejoin=\"round\" class=\"pu-faq-c\" style=\"width:1em;height:1em;flex:none;opacity:0.6;transition:transform 0.15s\" aria-hidden=\"true\"\u003e\u003cpath d=\"M6 9l6 6l6 -6\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/summary\u003e\u003cp style=\"margin:0.4em 0 0\"\u003eThis kit fits Big Twin models from 1978 to 1984 equipped with a 1340cc Shovelhead engine.\u003c\/p\u003e\u003c\/details\u003e\u003c\/td\u003e\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003c\/td\u003e\u003c\/tr\u003e\u003c\/tbody\u003e\u003c\/table\u003e","brand":"Keith Black Pistons","offers":[{"title":"Default Title","offer_id":49681014685952,"sku":"KB297.STD","price":597.31,"currency_code":"NZD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0855\/0888\/2688\/files\/KB297.STD.jpg?v=1788494882","url":"https:\/\/baychoppers.co.nz\/products\/keith-black-pistons-dome-top-pistons-kb297-std-for-big-twin-1978-1984","provider":"Bay Choppers NZ","version":"1.0","type":"link"}