Mazda Miata 1.8 lts 83.50mm(+0.5)/ 4032/ Forged piston/Comp. height 30.5mm (STD)/ -4cc Dish /20mm pin Off Center/ Rings 1, 1.2, 2.8mm. /Valve pocket depth Int.: 4mm – Exh: 3mm /C.R.: 8.6:1