{"product_id":"80-inch-evolution-domed-piston-kit-030","title":"80 inch Evolution Domed Piston Kit .030","description":"\u003cp\u003eKeith Black dome piston set is .030 oversize with a 10.5:1 compression ratio for 1984-up Big Twin Evolution models.\n\u003cbr\u003eThe Keith Black 390 hypereutectic alloy is cast in a permanent steel mold which makes it possible to build a light weight piston that makes more power and uses less fuel and lasts longer. Pistons are .030 over sized  for a 3.498 inch bore and has a 10.5:1 compression ratio.  The low heat transfer of the alloy keeps the skirts cool so piston expansion is minimal. The combination of a low heat transfer piston alloy and high compression ring placement increases power and economy. The high ring placement alone reduces detonation and increases the top ring temperature.                                                           **Note: Run engine at moderate speeds for at least 500 miles  avoiding excessive running in lower gears  in order to properly break-in new pistons and rings. \n\u003cbr\u003e Instructions: http:\/\/www.vtwinmfg.com\/Instructions\/MS\/KB Conversion Piston Guide and Fitment.pdf\u003c\/p\u003e","brand":"Keith Black","offers":[{"title":"Default Title","offer_id":67617158070457,"sku":"11-2226","price":309.99,"currency_code":"USD","in_stock":false}],"url":"https:\/\/www.thespeedshopusa.com\/fr\/products\/80-inch-evolution-domed-piston-kit-030","provider":"THE SPEED SHOP USA","version":"1.0","type":"link"}