{"product_id":"brian-crower-honda-acura-k20a-a2-k24a2-f20-22-dual-valve-springs","title":"Brian Crower Dual Valve Springs \u0026 Retainers for K20\/K24\/F Series","description":"\u003cul\u003e\n\u003cli\u003eDual Spring Design \u003c\/li\u003e\n\u003cli\u003eGreat Upgrade to Accompany Cams \u003c\/li\u003e\n\u003cli\u003eAvailable in Steel or Titanium Retainer\/Seats \u003c\/li\u003e\n\u003cli\u003eFits K20A, K20Z3, and K24A2 Engines \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=\"#Included\"\u003eIncluded\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\u003eBrian Crower Dual Valve Springs \u0026amp; Retainers - K20, K24 \u0026amp; F-Series\u003c\/h3\u003e\n\n\u003cp\u003eValve springs are the part of a cam upgrade people underestimate. Bigger cams and higher rpm ask far more of the springs than the factory profile does, and stock springs are what let go first. These BC dual springs are wound by PAC Racing from high grade chrome silicone alloy, rated to 0.550\" net cam lift, and they're the supporting hardware serious K-series and F-series builds are built around.\u003c\/p\u003e\n\n\u003ch4\u003eRead This If Your Head Is 2004 Or Newer\u003c\/h4\u003e\n\n\u003cp\u003eImportant warning, and it affects a lot of people.\u003c\/p\u003e\n\n\u003cp\u003eHonda changed the keeper groove angles on late model cylinder heads. If yours is \u003cstrong\u003e2004 or newer\u003c\/strong\u003e, your factory keepers may not fit the BC retainers properly, and Brian Crower is explicit that this can cause damage.\u003c\/p\u003e\n\n\u003cp\u003eThe fix is \u003cstrong\u003eBC2940 keepers\u003c\/strong\u003e, sourced alongside this kit. If there's any chance your head is a late model, get them in the same order rather than finding out with the head apart or, worse, after the engine is running.\u003c\/p\u003e\n\n\u003cp\u003eThis applies to both the BC2010 titanium and BC2011 steel retainers, so it's not something you avoid by picking one over the other.\u003c\/p\u003e\n\n\u003ch4\u003eTitanium Or Steel Retainers?\u003c\/h4\u003e\n\n\u003cp\u003eTwo versions of the kit, and the difference is what the retainers are made of.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eBC0040 uses titanium retainers (BC2010).\u003c\/strong\u003e Lighter, which reduces valvetrain mass and helps the springs control the valve at high rpm. This is the choice for a race or high rpm application where every gram of reciprocating weight matters.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eBC0040S uses steel retainers (BC2011).\u003c\/strong\u003e Heavier than titanium but considerably more durable over time, which is why Brian Crower positions steel for streetability. If the car sees regular road use and you want the valvetrain to last without thinking about it, steel is the sensible pick.\u003c\/p\u003e\n\n\u003cp\u003eHonest guidance: titanium is the right call for a dedicated race engine, steel for anything that's still a street car. Titanium retainers are a wear item in a way steel isn't, and on a car doing thousands of road miles a year that matters more than the weight savings.\u003c\/p\u003e\n\n\u003ch4\u003eWhy Springs Come First\u003c\/h4\u003e\n\n\u003cp\u003eWorth explaining, because it's the reason these are a hard requirement rather than an upgrade.\u003c\/p\u003e\n\n\u003cp\u003eYour valve spring's job is closing the valve, and it has to do that faster than the cam is trying to open it. Increase lift or add duration and the spring has more work to do in less time.\u003c\/p\u003e\n\n\u003cp\u003eWhen a spring can't keep up, the valve floats. It doesn't fully close when it should, and on an interference engine that means a valve sitting in the path of a piston. That's the failure mode, and it's why every cam manufacturer specifies springs alongside their profiles.\u003c\/p\u003e\n\n\u003cp\u003eThese are rated to 0.550\" net cam lift, which covers the aggressive profiles people run on these engines.\u003c\/p\u003e\n\n\u003ch4\u003ePAC Racing Construction\u003c\/h4\u003e\n\n\u003cp\u003eBC valve springs are wound by PAC Racing from the highest grade, super clean chrome silicone alloy, using proprietary processing for consistent pressures across the set.\u003c\/p\u003e\n\n\u003cp\u003eThat consistency matters more than the headline pressure figure. A set where one spring sits meaningfully off the others means one valve behaving differently from the rest, which shows up as a cylinder that doesn't match on a dyno and, at the limit, a valve that floats before the others do.\u003c\/p\u003e\n\n\u003ch4\u003eSpecifications\u003c\/h4\u003e\n\n\u003ctable\u003e\n    \u003cthead\u003e\n        \u003ctr\u003e\n            \u003cth scope=\"col\"\u003e\u003cbr\u003e\u003c\/th\u003e\n            \u003cth scope=\"col\"\u003eBC0040 (Titanium)\u003c\/th\u003e\n            \u003cth scope=\"col\"\u003eBC0040S (Steel)\u003c\/th\u003e\n        \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n        \u003ctr\u003e\n\u003ctd\u003eSpring\u003c\/td\u003e\n\u003ctd\u003eBC1040 dual\u003c\/td\u003e\n\u003ctd\u003eBC1040 dual\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eRetainer\u003c\/td\u003e\n\u003ctd\u003eBC2010 titanium\u003c\/td\u003e\n\u003ctd\u003eBC2011 steel\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eSpring seat\u003c\/td\u003e\n\u003ctd\u003eBC2904\u003c\/td\u003e\n\u003ctd\u003eBC2904\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eFree length\u003c\/td\u003e\n\u003ctd\u003e2.025\"\u003c\/td\u003e\n\u003ctd\u003e2.025\"\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eSeat pressure\u003c\/td\u003e\n\u003ctd\u003e1.590\" at 80 lbs\u003c\/td\u003e\n\u003ctd\u003e1.590\" at 80 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eOpen pressure\u003c\/td\u003e\n\u003ctd\u003e1.110\" at 250 lbs\u003c\/td\u003e\n\u003ctd\u003e1.110\" at 250 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eCoil bind\u003c\/td\u003e\n\u003ctd\u003e1.030\"\u003c\/td\u003e\n\u003ctd\u003e1.030\"\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003ctd\u003eNet cam lift\u003c\/td\u003e\n\u003ctd\u003e0.550\" \/ 13.97mm\u003c\/td\u003e\n\u003ctd\u003e0.550\" \/ 13.97mm\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch4\u003eDo It While The Head Is Off\u003c\/h4\u003e\n\n\u003cp\u003eInstalling valve springs means the head is apart, which is most of the labor. Use the access.\u003c\/p\u003e\n\n\u003cp\u003eInspect your valve guides and seals while everything is exposed, since those wear on a high mileage engine and reaching them later means the same teardown. And if cams are anywhere in your plan, this is the moment to fit them rather than doing this job twice.\u003c\/p\u003e\n\n\u003ch4\u003eFitment\u003c\/h4\u003e\n\n\u003cp\u003eHonda and Acura K20A, K20Z3, K24A2, F20C, and F22C engines.\u003c\/p\u003e\n\n\u003cp\u003eBC0040 (titanium retainers) or BC0040S (steel retainers). \u003cstrong\u003eHeads from 2004 onward may require BC2940 keepers.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003ch4\u003eWho Should Run These\u003c\/h4\u003e\n\n\u003cp\u003eThis is for anyone fitting aggressive cams, and for the builder who's chasing rpm and needs the valvetrain to keep up. It's supporting hardware rather than a power part, which is exactly why it gets skipped and exactly why skipping it is expensive. Pick titanium for a race engine or steel for a street car, sort your keepers if you're on a late head, and build the top end properly.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eFits:\u003c\/strong\u003e Honda and Acura K20A, K20Z3, K24A2, F20C, and F22C. \u003cstrong\u003ePart numbers:\u003c\/strong\u003e BC0040 (titanium retainers) and BC0040S (steel retainers). \u003cstrong\u003eSpring:\u003c\/strong\u003e BC1040 dual, wound by PAC Racing from chrome silicone alloy. \u003cstrong\u003eRated to:\u003c\/strong\u003e 0.550\" net cam lift. \u003cstrong\u003eIncludes:\u003c\/strong\u003e springs, retainers, and spring seats. \u003cstrong\u003eImportant:\u003c\/strong\u003e 2004 and later cylinder heads may require BC2940 keepers due to changed keeper groove angles.\u003c\/p\u003e\n\u003c\/li\u003e\n\n \n\u003cli id=\"VehicleFitment\"\u003e\n \u003cp\u003e2002-2006 Acura RSX Type S\u003cbr\u003e2004-2008 Acura TSX\u003cbr\u003e2006-2011 Honda Civic Si\u003c\/p\u003e \n\u003c\/li\u003e\n\n\n\n\n\u003cli id=\"TechnicalData\"\u003e\n\u003cp\u003eFree Length - 2.025\"\u003c\/p\u003e\n\u003cdiv\u003eSeat - 1.590\" @ 80 lbs\u003c\/div\u003e\n\u003cdiv\u003eOpen - 1.110\" @ 250 lbs\u003c\/div\u003e\n\u003cdiv\u003eCoil Bind - 1.030\"\u003c\/div\u003e\n\u003cdiv\u003eRetainer - BC2011\u003c\/div\u003e\n\u003cdiv\u003eSpring Seat - BC2904\u003c\/div\u003e\n\u003cdiv\u003eNet Cam Lift - 0.550\" \/ 13.97mm  \u003c\/div\u003e\n\u003c\/li\u003e\n\n\n\n \n\u003cli id=\"Included\"\u003e\n\u003cdiv\u003e(16) Springs\u003cbr\u003e\u003cspan style=\"font-style: italic;\"\u003e(16) Retainers\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan style=\"font-style: italic;\"\u003e(16) Seats\u003c\/span\u003e\u003c\/div\u003e\n\u003c\/li\u003e\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":"Brian Crower","offers":[{"title":"Titanium Retainer\/Seat","offer_id":47372052529186,"sku":"BRC-BC0040","price":488.0,"currency_code":"USD","in_stock":false},{"title":"Steel Retainer\/Seat","offer_id":47372052561954,"sku":"BRC-BC0040S","price":402.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/2218\/5701\/files\/group-40b2a953-62cb-4226-9681-8afbf47cb06d-800.jpg?v=1788894414","url":"https:\/\/www.hybrid-racing.com\/products\/brian-crower-honda-acura-k20a-a2-k24a2-f20-22-dual-valve-springs","provider":"Hybrid Racing","version":"1.0","type":"link"}