{"product_id":"kpmi-cylinder-stud-kits-studs-pkg-of-8-191-58018","title":"KPMI 8-Piece Cylinder Stud Kit - Harley Milwaukee-Eight Touring \u0026 Softail","description":"\u003c!-- vt:seo-start --\u003e\n\u003cdiv class=\"vt-brand-bio\" style=\"background:#f6f6f6;border-left:4px solid #c8102e;padding:14px 18px;margin:0 0 20px;border-radius:4px;\"\u003e\n\u003ch2 style=\"margin:0 0 6px;font-size:1.05em;\"\u003eAbout KPMI\u003c\/h2\u003e\n\u003cp style=\"margin:0;font-size:0.95em;line-height:1.6;\"\u003eKibblewhite Precision Machining supplies valves, valve springs, guides and complete top-end kits used by professional V-twin engine builders. Its black diamond valves and spring kits are a standard specification on high-lift cam builds.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cp style=\"line-height:1.65;\"\u003eFortify your V-twin engine's top end with the KPMI 8-Piece Cylinder Stud Kit. These high-performance studs are manufactured from premium grade 8740 alloy steel, heat-treated to an impressive 180,000 psi yield strength. Crucially, the threads are rolled post-heat-treatment to maximize fatigue resistance and ensure consistent compressive stress at sustained high temperatures, vital for demanding Harley-Davidson and Indian Motorcycle applications.\u003c\/p\u003e\n\u003ch3 style=\"margin:20px 0 6px;\"\u003eWhy riders pick this\u003c\/h3\u003e\u003cul style=\"padding-left:20px;margin:0 0 16px;\"\u003e\n\u003cli style=\"margin:3px 0;\"\u003eGrade 8740 alloy steel, 180,000 psi yield strength\u003c\/li\u003e\n\u003cli style=\"margin:3px 0;\"\u003eThreads rolled after heat-treat for superior fatigue life\u003c\/li\u003e\n\u003cli style=\"margin:3px 0;\"\u003eInterference fit design maintains thread contact at high temps\u003c\/li\u003e\n\u003cli style=\"margin:3px 0;\"\u003eCenterless ground for precision and concentricity\u003c\/li\u003e\n\u003cli style=\"margin:3px 0;\"\u003ePremium black oxide finish for corrosion resistance\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eWhen you're building a high-performance Harley-Davidson or Indian Motorcycle engine, cylinder head retention is paramount. The KPMI Cylinder Stud Kit provides the superior clamping force and durability needed to prevent head lifting, even under extreme combustion pressures. These studs are a critical upgrade for any V-twin running higher compression, forced induction, or aggressive cam profiles, ensuring the integrity of your engine's sealing surfaces.\u003c\/p\u003e\n\u003ch3\u003eEngineered for Ultimate Engine Integrity\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eManufactured from premium grade 8740 material, heat-treated to 180,000 psi yield strength\u003c\/li\u003e\n\u003cli\u003eThreads rolled after heat treating for maximum fatigue life and strength\u003c\/li\u003e\n\u003cli\u003eSlight interference fit design maintains optimal thread contact at high temperatures\u003c\/li\u003e\n\u003cli\u003eCenterless ground for exceptional concentricity and precision fitment\u003c\/li\u003e\n\u003cli\u003ePremium black oxide finish provides corrosion resistance and a clean look\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eThe Foundation of a Strong Engine\u003c\/h3\u003e\n\u003cp\u003eA KPMI cylinder stud kit is an essential component for any serious V-twin engine build, providing a far more robust solution than factory bolts. The enhanced clamping force and superior material properties of these studs ensure cylinder head stability, preventing gasket leaks and maintaining peak performance. This 8-piece kit is designed for direct replacement, offering a significant upgrade in reliability and peace of mind for your Milwaukee-Eight Touring or Softail.\u003c\/p\u003e\n\u003ch3 style=\"margin:20px 0 6px;\"\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e KPMI\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part #:\u003c\/strong\u003e 20-21040\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eQuantity:\u003c\/strong\u003e 8 studs per package\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLength:\u003c\/strong\u003e 5 in\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWidth:\u003c\/strong\u003e 1 in\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHeight:\u003c\/strong\u003e 1.4 in\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 8 lbs\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"margin:22px 0 8px;\"\u003eCommon questions\u003c\/h3\u003e\u003cdiv class=\"vt-faq\"\u003e\n\u003cdiv style=\"margin:0 0 12px;\"\u003e\n\u003cp style=\"margin:0 0 3px;font-weight:600;\"\u003eWhat material are these cylinder studs made from?\u003c\/p\u003e\n\u003cp style=\"margin:0;line-height:1.6;\"\u003eThese KPMI cylinder studs are made from premium grade 8740 alloy steel, heat-treated to 180,000 psi yield strength, providing exceptional durability and resistance to stretching.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"margin:0 0 12px;\"\u003e\n\u003cp style=\"margin:0 0 3px;font-weight:600;\"\u003eWhy are the threads rolled after heat treating?\u003c\/p\u003e\n\u003cp style=\"margin:0;line-height:1.6;\"\u003eRolling the threads after heat treating maximizes the fatigue resistance and tensile strength of the studs. This process retains compressive stress in the thread roots, which significantly extends their lifespan under high-stress engine conditions.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"margin:0 0 12px;\"\u003e\n\u003cp style=\"margin:0 0 3px;font-weight:600;\"\u003eWill this 8-piece kit fit my Harley-Davidson Touring or Softail model?\u003c\/p\u003e\n\u003cp style=\"margin:0;line-height:1.6;\"\u003eThis 8-piece cylinder stud kit is designed for Harley-Davidson Milwaukee-Eight Touring and Softail models. Please use our Shop by Bike tool to confirm exact fitment for your specific year and model before purchasing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"vt-confidence\" style=\"border-top:1px solid #e5e5e5;margin:24px 0 0;padding:16px 0 0;font-size:0.92em;line-height:1.6;\"\u003e\n\u003ch3 style=\"margin:0 0 6px;\"\u003eOrdering from Vtwinbikers\u003c\/h3\u003e\n\u003cul style=\"padding-left:20px;margin:0;\"\u003e\n\u003cli\u003eBrand new, sourced through authorized US distribution — never used, never grey-market.\u003c\/li\u003e\n\u003cli\u003eNot sure it fits? Use \u003cstrong\u003eShop by Bike\u003c\/strong\u003e to filter by your year and model, or email us and we will confirm before you order.\u003c\/li\u003e\n\u003cli\u003eHarley-Davidson and Indian Motorcycle is all we do, so you are talking to people who ride what you ride.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\":\"https:\/\/schema.org\",\"@type\":\"BreadcrumbList\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/vtwinbikers.com\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Engine\",\"item\":\"https:\/\/vtwinbikers.com\/collections\/all\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"KPMI\",\"item\":\"https:\/\/vtwinbikers.com\/collections\/kpmi\"},{\"@type\":\"ListItem\",\"position\":4,\"name\":\"KPMI 8-Piece Cylinder Stud Kit - Harley Milwaukee-Eight Touring \u0026 Softail\",\"item\":\"https:\/\/vtwinbikers.com\/products\/kpmi-cylinder-stud-kits-studs-pkg-of-8-191-58018\"}]}\u003c\/script\u003e\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\":\"https:\/\/schema.org\",\"@type\":\"FAQPage\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"What material are these cylinder studs made from?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"These KPMI cylinder studs are made from premium grade 8740 alloy steel, heat-treated to 180,000 psi yield strength, providing exceptional durability and resistance to stretching.\"}},{\"@type\":\"Question\",\"name\":\"Why are the threads rolled after heat treating?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Rolling the threads after heat treating maximizes the fatigue resistance and tensile strength of the studs. This process retains compressive stress in the thread roots, which significantly extends their lifespan under high-stress engine conditions.\"}},{\"@type\":\"Question\",\"name\":\"Will this 8-piece kit fit my Harley-Davidson Touring or Softail model?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"This 8-piece cylinder stud kit is designed for Harley-Davidson Milwaukee-Eight Touring and Softail models. Please use our Shop by Bike tool to confirm exact fitment for your specific year and model before purchasing.\"}}]}\u003c\/script\u003e\n\u003c!-- vt:seo-end --\u003e","brand":"KPMI","offers":[{"title":"Default Title","offer_id":53035873271919,"sku":"191-58018","price":171.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0608\/6734\/6543\/files\/3149-5dfb8c9b851f3.jpg?v=1777529926","url":"https:\/\/vtwinbikers.com\/products\/kpmi-cylinder-stud-kits-studs-pkg-of-8-191-58018","provider":"Vtwinbikers","version":"1.0","type":"link"}