{"product_id":"4-185in-bore-forged-piston-set","title":"4.185in Bore Forged Piston Set","description":"The AutoTec Oldsmobile 455 Forged Piston Set (Part #1000586) is engineered for enhanced performance in Oldsmobile 455 engines. These pistons are crafted from a forged 4032 low-expansion, high-silicon aluminum alloy, offering excellent durability and suitability for street and strip applications.\n\nThe set includes flat-top pistons with two valve reliefs, designed for a 4.185-inch bore and a 4.250-inch stroke. Key specifications include a compression height of 1.750 inches, a wrist pin size of 0.980 inches, and CNC-machined ring grooves that accept 1.5mm top ring, 1.5mm second ring, and 3.0mm oil ring sizes. The pistons also feature diamond-turned skirts for reduced friction.\n\nCompression ratios vary based on combustion chamber volume: 12.3:1 with 72cc chambers, 11.3:1 with 80cc chambers, and 10.6:1 with 87cc chambers. This set is sold as a set of 8 pistons and comes with pin fit, wire locks, broached pin oilers, and accumulator grooves. Please note that rings are sold separately.","brand":"AutoTec","offers":[{"title":"Default Title","offer_id":52687687188792,"sku":"1000586","price":766.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0970\/4895\/3144\/files\/664192790.jpg?v=1784886109","url":"https:\/\/store.motormia.co\/products\/4-185in-bore-forged-piston-set","provider":"MOTORMIA","version":"1.0","type":"link"}