{"product_id":"bourne-hpp-prb-cylinder-head-beryllium-seats-guides","title":"Bourne HPP K20 Cylinder Head - Beryllium Copper Seats \u0026 Guides","description":"\u003cul\u003e\n\u003cli\u003eBeryllium Copper Seats \u0026amp; Guides (F1-Grade) \u003c\/li\u003e\n\u003cli\u003eSheds Heat, Resists Valve Seat Recession \u003c\/li\u003e\n\u003cli\u003eNew Bare Head — No Core Or Exchange \u003c\/li\u003e\n\u003cli\u003eK24A4 \u0026amp; K24A8 Require New Pistons \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 \u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\n\n\u003cli class=\"active\" id=\"Description\"\u003e\n\u003ch3\u003eBourne HPP K20 Cylinder Head - Beryllium Copper Seats \u0026amp; Guides\u003c\/h3\u003e\n\n\u003cp\u003eThis is a new, bare K20 cylinder head built to a specification most people never see outside professional motorsport: beryllium copper valve seats and guides in place of the factory steel. It's the head for the serious K-series builder who's chasing reliability at high RPM or under boost, where heat and sealing are what separate an engine that holds together from one that doesn't. Sold as a new bare head, no core or exchange required.\u003c\/p\u003e\n\n\u003ch4\u003eWhy Beryllium Copper Is A Motorsport Material\u003c\/h4\u003e\n\n\u003cp\u003eWorth understanding, because it's the entire reason this head exists and what you're paying for.\u003c\/p\u003e\n\n\u003cp\u003eValve seats and guides are where the valvetrain meets the head, and on a hard-working engine they're managing two problems at once: shedding enormous heat (especially on the exhaust side) and maintaining a perfect seal. Factory steel and cast-iron seats are adequate for a stock engine, but under high RPM, high heat, or forced induction, they reach their limits, they retain heat, they can sink over time, and they lose their seal.\u003c\/p\u003e\n\n\u003cp\u003eBeryllium copper (Be-Cu) is the material Formula 1, Le Mans, and NASCAR engines use to solve exactly this. It conducts heat dramatically better than steel and it's exceptionally tough, which addresses both problems at once. This head brings that specification to the K-series.\u003c\/p\u003e\n\n\u003ch4\u003eIt Runs Cooler Where It Matters\u003c\/h4\u003e\n\n\u003cp\u003eHeat management is the headline benefit, particularly on the exhaust valves.\u003c\/p\u003e\n\n\u003cp\u003eBe-Cu is an exceptional thermal conductor, far better than steel. It actively pulls heat away from the valves, especially the exhaust valves that run hottest, and moves it into the head to be carried away by the cooling system. Lower valve and combustion chamber temperatures mean a \u003cstrong\u003ereduced risk of detonation\u003c\/strong\u003e, which is the failure mode that destroys boosted and high-compression engines.\u003c\/p\u003e\n\n\u003cp\u003eThat cooling has a second benefit: it lets you run more aggressive ignition timing without detonation, so the head doesn't just survive better, it can make more power safely. And because the guides shed heat so effectively, they hold their concentricity and their oil film better, which means less wear on both the valve stems and the guides over time.\u003c\/p\u003e\n\n\u003ch4\u003eIt Seals Better, And Stays Sealed\u003c\/h4\u003e\n\n\u003cp\u003eSealing is where compression and power come from, and Be-Cu seals in a way steel can't.\u003c\/p\u003e\n\n\u003cp\u003eBe-Cu is softer than OE steel, which sounds like a drawback but isn't, it lets the valve seats lap in and conform precisely to the valve face, creating a tighter seal that reduces the small percentage of leak-down present in standard heads. Better sealing means better compression and more consistent power.\u003c\/p\u003e\n\n\u003cp\u003eCritically, it also \u003cstrong\u003eexpands far less than steel\u003c\/strong\u003e under operating temperature. Steel seats distort as they heat, which is how a head that sealed cold loses its seal hot. Be-Cu holds its geometry across the temperature range, so the seal you have on the dyno is the seal you have deep into a session.\u003c\/p\u003e\n\n\u003ch4\u003eIt Won't Sink Or Gall\u003c\/h4\u003e\n\n\u003cp\u003eThe durability points that matter at the redline.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eNo valve seat recession.\u003c\/strong\u003e Over years and hard use, factory seats sink, the valve hammers a softening seat deeper into the casting, which changes your valve lash and kills port flow. Be-Cu is tough enough to resist that pounding, even from high-lift race cams, so it holds consistent valve lash and flow rather than receding.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eNatural galling resistance.\u003c\/strong\u003e Be-Cu resists galling by its nature, so at the extreme valve speeds of high RPM, you're far less likely to damage a guide. The valvetrain keeps moving smoothly, cycle after cycle, where lesser materials would scuff and seize.\u003c\/p\u003e\n\n\u003cp\u003eThat galling resistance also makes Be-Cu the \u003cstrong\u003erequired seat material if you run titanium valves\u003c\/strong\u003e. Titanium galls and seizes against steel seats, so it needs a compatible material like Be-Cu to run reliably, this head is ready for a titanium valvetrain where a standard head isn't.\u003c\/p\u003e\n\n\u003ch4\u003ePairs With Bourne HPP EN52 Valves\u003c\/h4\u003e\n\n\u003cp\u003eWorth knowing, since the seat and valve work as a system, and since the valvetrain is sold separately.\u003c\/p\u003e\n\n\u003cp\u003eA head is only as good as the match between the seat and the valve. Bourne HPP makes their own race valves from \u003ca href=\"#\"\u003eEN52 silicon chrome steel\u003c\/a\u003e, a high-tensile alloy chosen for fatigue resistance and thermal stability at high temperature.\u003c\/p\u003e\n\n\u003cp\u003ePaired with the Be-Cu seats, the heat is pulled out of the EN52 valve face more efficiently than any other combination, which extends valve life and prevents \"tuliping\" (the valve head deforming under heat and load). If you're building this head out, the matched \u003ca href=\"#\"\u003eEN52 valve set\u003c\/a\u003e is the intended companion, and titanium valves are also fully compatible thanks to the Be-Cu seats.\u003c\/p\u003e\n\n\u003ch4\u003eBe-Cu Versus Standard, At A Glance\u003c\/h4\u003e\n\n\u003ctable\u003e\n    \u003cthead\u003e\n        \u003ctr\u003e\n            \u003cth scope=\"col\"\u003eFeature\u003c\/th\u003e\n            \u003cth scope=\"col\"\u003eStandard OEM\u003c\/th\u003e\n            \u003cth scope=\"col\"\u003eBourne HPP Be-Cu\u003c\/th\u003e\n        \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n        \u003ctr\u003e\n\u003ctd\u003eSeat material\u003c\/td\u003e\n\u003ctd\u003eCast iron (retains heat)\u003c\/td\u003e\n\u003ctd\u003eBeryllium copper (sheds heat)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eHeat transfer\u003c\/td\u003e\n\u003ctd\u003eLow\u003c\/td\u003e\n\u003ctd\u003eExceptional, protects valves\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eWear resistance\u003c\/td\u003e\n\u003ctd\u003eProne to sinking\u003c\/td\u003e\n\u003ctd\u003eExceptional impact resistance\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eRecommended valve\u003c\/td\u003e\n\u003ctd\u003eStandard steel\u003c\/td\u003e\n\u003ctd\u003eEN52 steel or titanium\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch4\u003eSold As A New Bare Head\u003c\/h4\u003e\n\n\u003cp\u003eClear on exactly what you're getting, since this is a premium purchase and you'll be building it out.\u003c\/p\u003e\n\n\u003cp\u003eThis is a \u003cstrong\u003enew, bare K20 cylinder head\u003c\/strong\u003e with the beryllium copper valve seats and guides installed. It does \u003cstrong\u003enot\u003c\/strong\u003e include valves, springs, retainers, cams, or other valvetrain components, those are sold separately, so you can spec the valvetrain to your build.\u003c\/p\u003e\n\n\u003cp\u003eThere's \u003cstrong\u003eno core charge and no exchange required\u003c\/strong\u003e. You're not sending in your old head or waiting on a rebuild of your core, you order the head, it ships, and you build it out with the valvetrain of your choice. For a fresh build, or an engine where you'd rather start with a known-new Be-Cu casting than have your existing head modified, that's the straightforward path.\u003c\/p\u003e\n\n\u003ch4\u003eFitment\u003c\/h4\u003e\n\n\u003cp\u003eThis K20 head fits the following engines. Note the Accord and Element require new pistons (see below).\u003c\/p\u003e\n\n\u003ctable\u003e\n    \u003cthead\u003e\n        \u003ctr\u003e\n            \u003cth scope=\"col\"\u003eVehicle\u003c\/th\u003e\n            \u003cth scope=\"col\"\u003eEngine\u003c\/th\u003e\n        \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n        \u003ctr\u003e\n\u003ctd\u003e2002-2006 Acura RSX\u003c\/td\u003e\n\u003ctd\u003eK20A2 \/ K20A3 \/ 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\u003e2006-2011 Honda Civic Si\u003c\/td\u003e\n\u003ctd\u003eK20Z3\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003e2004-2008 Acura TSX\u003c\/td\u003e\n\u003ctd\u003eK24A2\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003e2002-2006 Honda CR-V\u003c\/td\u003e\n\u003ctd\u003eK24A1\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003e2003-2007 Honda Accord*\u003c\/td\u003e\n\u003ctd\u003eK24A4 \/ K24A8\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003e2003-2011 Honda Element*\u003c\/td\u003e\n\u003ctd\u003eK24A4 \/ K24A8\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003cp\u003e\u003cstrong\u003e*Accord and Element (K24A4 \/ K24A8): requires new pistons and rods.\u003c\/strong\u003e See below.\u003c\/p\u003e\n\n\u003ch4\u003eWhy The Accord And Element Need New Pistons\u003c\/h4\u003e\n\n\u003cp\u003eImportant for anyone putting this K20 head on a K24A4 or K24A8 block.\u003c\/p\u003e\n\n\u003cp\u003eThe K24A4 (Accord\/Element) and K24A8 (later Accord\/Element) use pistons that will \u003cstrong\u003ephysically contact the valves\u003c\/strong\u003e of a K20 cylinder head, a valve-to-piston clearance problem. Running this head on those blocks without addressing it means the pistons hit the valves, which destroys the engine.\u003c\/p\u003e\n\n\u003cp\u003eThe fix is new pistons, aftermarket pistons (or K20A2-type pistons) that provide the correct valve clearance for this head, and on a proper build, matched rods to go with them. If you're building one of these K24A4 or K24A8 blocks with this head, budget for pistons and rods as part of the job.\u003c\/p\u003e\n\n\u003cp\u003eThe RSX, Civic Si, TSX, and CR-V engines listed above don't have this issue and run this head without piston changes. For the full details on combining a K24 bottom end with a K20 head, our \u003ca href=\"https:\/\/www.hybrid-racing.com\/blogs\/hybrid-racing\/k20-k24-hybrid-engine-build-guide\"\u003eK20\/K24 hybrid engine build guide\u003c\/a\u003e walks through the whole process.\u003c\/p\u003e\n\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\n\u003cul\u003e\n    \u003cli\u003eEngine: Honda K20 head (fits K20 and K24 applications, see fitment)\u003c\/li\u003e\n    \u003cli\u003eSeats and guides: beryllium copper (Be-Cu)\u003c\/li\u003e\n    \u003cli\u003eCondition: new, bare head (no core or exchange)\u003c\/li\u003e\n    \u003cli\u003eValvetrain: valves, springs, retainers, and cams sold separately\u003c\/li\u003e\n    \u003cli\u003eRecommended valves: EN52 steel or titanium\u003c\/li\u003e\n    \u003cli\u003eBest for: high-RPM naturally aspirated, forced induction, and track use\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch4\u003eWho Should Grab This\u003c\/h4\u003e\n\n\u003cp\u003eThis is for the serious K-series builder whose engine sees high RPM, boost, or track use, and who wants the valvetrain sealing and heat management sorted to a motorsport standard rather than the factory one. Be-Cu seats and guides that shed heat, seal tighter, resist sinking and galling, and accept titanium valves. It's a premium bare head for a premium build. Check whether your block needs pistons, spec your valvetrain with \u003ca href=\"#\"\u003eEN52\u003c\/a\u003e or titanium valves, and build an engine that holds together at the limit.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eFits:\u003c\/strong\u003e 2002-2006 RSX, 2002-2005 \u0026amp; 2006-2011 Civic Si, 2004-2008 TSX, 2002-2006 CR-V, 2003-2007 Accord, 2003-2011 Element (see engine chart above). \u003cstrong\u003eAccord\/Element (K24A4\/A8):\u003c\/strong\u003e require new pistons and rods. \u003cstrong\u003eSeats \u0026amp; guides:\u003c\/strong\u003e beryllium copper. \u003cstrong\u003eCondition:\u003c\/strong\u003e new bare head, no core or exchange. \u003cstrong\u003eValvetrain:\u003c\/strong\u003e valves, springs, retainers sold separately. \u003cstrong\u003eRecommended valves:\u003c\/strong\u003e \u003ca href=\"#\"\u003eBourne HPP EN52\u003c\/a\u003e or titanium. \u003cstrong\u003eBenefits:\u003c\/strong\u003e superior heat dissipation, tighter and more stable sealing, resistance to valve seat recession and galling, titanium-valve compatible. \u003cstrong\u003eBest for:\u003c\/strong\u003e high-RPM NA, forced induction, track.\u003c\/p\u003e\n\u003c\/li\u003e\n\n \n\u003cli id=\"VehicleFitment\"\u003e\n \u003cp\u003e2002-2006 Acura RSX\u003cbr\u003e2004-2008 Acura TSX\u003cbr\u003e2003-2007 Honda Accord*\u003cbr\u003e2002-2005 Honda Civic Si\u003cbr\u003e2006-2011 Honda Civic Si\u003cbr\u003e2002-2006 Honda CR-V\u003cbr\u003e2003-2011 Honda Element*\u003cbr\u003e*Requires New Pistons\/Rods\u003c\/p\u003e \n\u003c\/li\u003e\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\u003c\/ul\u003e\n","brand":"Bourne HPP","offers":[{"title":"Default Title","offer_id":67608839290914,"sku":"BHP-K20CHB-CC-1","price":2009.76,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/2218\/5701\/files\/BHP-K20CHB-CC-1_6srr.jpg?v=1790797009","url":"https:\/\/www.hybrid-racing.com\/products\/bourne-hpp-prb-cylinder-head-beryllium-seats-guides","provider":"Hybrid Racing","version":"1.0","type":"link"}