4mil short rod 513 66mm pistons stock cylinders 4mil 19cc dimes squish is 44 thousandths compression was 205 each cylinder . Now the fun Distorted piston after plug center came out BR7ES .30 gap . 35mm air strikers 160 main 48 pilots center on needle . C16 fuel 40-1 Elevation between 2000ft an 3000ft different 1/8 miles . So I need help new piston an dome on the way . An ported to 196 on a deg wheel maybe 10 passes .