Engine Size and Compression [ Close Window ] Fill in either SAE or Metric values. Then click on when finished. Cylinder Diameter  (inches ex: 4.25) Cylinder Diameter (mm) Stroke Length (inches ex: 4.25) Stroke Length (mm) Number of cylinders (4, 5, 6, 8) Number of cylinders Chamber in cc's (ex: 119) Chamber in cc's Piston dome in cc's  (Dome = positive #, Flat = 0, dished = negative number) (ex: 22) Piston dome in cc's Gasket Thickness in inches (add plus or minus amount piston is in the hole) (ex: .042) Gasket Thickness in mm (add plus or minus amount piston is in the hole) The displacement is cubic inches or liters. You also have a Compression ratio of       :1