{"product_id":"brian-crower-k20-crankshaft-for-acura-rsx-and-honda-civic","title":"Brian Crower K20 102mm Crankshaft for RSX and Civic","description":"\u003cul\u003e\n\u003cli\u003eAerospace-grade 4340 steel construction \u003c\/li\u003e\n\u003cli\u003eLarge radius journals for rigidity \u003c\/li\u003e\n\u003cli\u003eAdvanced micro-polished oil holes \u003c\/li\u003e\n\u003cli\u003eMulti-step heat treatment for durability \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 K20 102mm Stroker Crankshaft with B18A Rod Journals - 02-06 Acura RSX (DC5) \/ 02-11 Honda Civic Si (EP3\/FG2\/FA5)\u003c\/h3\u003e\n\u003cp\u003eA K20 comes from the factory with an 86mm stroke. It's a great short stroke for revving, but it caps how much displacement you get out of the block. There's only one way to add a lot of displacement without boring the cylinders out past what they'll safely take: make the crank throw farther. This Brian Crower crank takes the stroke to 102mm. That's even longer than the 99mm stroke in a K24. With a stock 86mm bore, that works out to roughly 2.37 liters, up from 2.0, all in the K20 block your car already has.\u003c\/p\u003e\n\u003cp\u003eYou'll notice it everywhere below the top of the rev range. More displacement means more torque at every RPM, so boost comes on sooner on a turbo build, and an N\/A car pulls harder out of corners instead of waiting for VTEC. There's a tradeoff, though. A longer stroke means the pistons travel farther and faster on every revolution. At 9,000 RPM, a 102mm stroke has the pistons moving about 18% faster on average than the stock 86mm does. Don't plan to rev a 102mm stroker like a stock-stroke K20. Build it for torque and a sensible rev limit, and you'll be happy with it.\u003c\/p\u003e\n\u003ch4\u003eWhy B18A Rod Journals\u003c\/h4\u003e\n\u003cp\u003eThe rod journals are where the connecting rods bolt onto the crank. This crank uses B18A-size rod journals instead of the factory K20 size. Smaller journals mean smaller rod big ends, and that buys clearance. When the crank swings that far, the rods come close to the block and the bottoms of the cylinders, and the smaller big ends keep things from hitting. It also means stock K20 rods won't fit. You'll need rods built for B18A-size journals at the right length for your pistons.\u003c\/p\u003e\n\u003ch4\u003e4340 Billet: What That Actually Means\u003c\/h4\u003e\n\u003cp\u003e4340 is a nickel-chromium-molybdenum steel alloy, the standard for high-strength rotating parts. \"Billet\" means the crank is machined from a solid bar instead of being forged close to shape first. That's how Brian Crower can make a stroke this far from stock. A forging needs its own expensive set of dies for each design, but a billet crank is just a different program on the CNC machine. The journals have large radiuses (the fillets where each journal meets the crank web), which spread stress over a wider area instead of concentrating it at a sharp corner. That's where cranks usually crack.\u003c\/p\u003e\n\u003ch4\u003eOiling and Surface Treatment\u003c\/h4\u003e\n\u003cp\u003eThe oil passages are gun-drilled and then ground smooth. The holes are shaped like a teardrop where they meet the bearing surface, so they catch more oil as the crank spins. They're also cross-drilled, so oil from the main bearings feeds the rod bearings first. The journals are polished to a mirror finish so the bearings ride on a smooth film of oil.\u003c\/p\u003e\n\u003cp\u003eAfter machining, the crank is stress-relieved to remove leftover tension in the metal. Then it's shot-peened, which means blasting the surface with small steel shot. That packs the surface tighter so cracks have a harder time starting. Next it's nitrided, a heat treatment that hardens the surface for bearing wear while keeping the core tough. Every crank is also magnafluxed, which means inspecting it with magnetic particles to catch any crack before it ships. The counterweights are fully profiled, meaning shaped to slice through the oil mist in the crankcase instead of paddling through it. That's less drag at high RPM.\u003c\/p\u003e\n\u003ch4\u003eBuild Notes: This Isn't a Drop-In\u003c\/h4\u003e\n\u003cp\u003eThis crank is the center of a full stroker build, not a part you swap in on its own. You'll need rods with B18A-size big ends and pistons with the right compression height for a 102mm stroke. Talk to your engine builder about the rod length and piston combination before you order anything. Expect a machine shop to check every clearance, including rods to block, counterweights to block, and pistons at bottom dead center. The whole rotating assembly will need to be balanced together. And the car will need a tune for the new displacement before it runs right.\u003c\/p\u003e\n\u003ch4\u003eFitment\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e2002-2006 Acura RSX Base and Type S (DC5) - K20A2, K20A3, K20Z1\u003c\/li\u003e\n\u003cli\u003e2002-2005 Honda Civic Si (EP3) - K20A3\u003c\/li\u003e\n\u003cli\u003e2006-2011 Honda Civic Si (FG2\/FA5) - K20Z3\u003c\/li\u003e\n\u003cli\u003e2008 Honda Civic Mugen Si - K20Z3\u003c\/li\u003e\n\u003cli\u003eK20 block only. Requires rods with B18A-size big ends and pistons built for a 102mm stroke\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n \n\u003cli id=\"VehicleFitment\"\u003e\n \u003cp\u003e\u003cspan class=\"tag\"\u003e2002-2006 Acura RSX \u003c\/span\u003e\u003c\/p\u003e\n\u003cbr\u003e\u003cp\u003e\u003cspan class=\"tag\"\u003e2002-2006 Acura RSX Type-S\u003c\/span\u003e\u003c\/p\u003e\n\u003cbr\u003e\u003cp\u003e\u003cspan class=\"tag\"\u003e2006-2011 Honda Civic \u003c\/span\u003e\u003c\/p\u003e\n\u003cbr\u003e\u003cp\u003e\u003cspan class=\"tag\"\u003e2006-2011 Honda Civic Si\u003c\/span\u003e\u003c\/p\u003e\n\u003cbr\u003e\u003cp\u003e\u003cspan class=\"tag\"\u003e2002-2005 Honda Civic Si\u003c\/span\u003e\u003c\/p\u003e\n\u003cbr\u003e\u003cp\u003e\u003cspan class=\"tag\"\u003e2001-2005 Honda Civic \u003c\/span\u003e\u003c\/p\u003e\n\u003cbr\u003e \n\u003c\/li\u003e\n\n\n\n\n\u003cli id=\"TechnicalData\"\u003e\n\n\u003c\/li\u003e\n\n\n\n \n\u003cli id=\"Included\"\u003e\n\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":"Default Title","offer_id":69648140337186,"sku":"BRC-BC5049","price":2614.5,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/2218\/5701\/files\/BRC-BC5049_0kmo.jpg?v=1793893941","url":"https:\/\/www.hybrid-racing.com\/products\/brian-crower-k20-crankshaft-for-acura-rsx-and-honda-civic","provider":"Hybrid Racing","version":"1.0","type":"link"}