Piston Calculators

To help you figure out exactly what parts you need to build that perfect machine, United Engine and Machine has put together the following group of calculators and converters.

While using these calculators in your planning, please remember the following:

  • While these calculators will calculate out to six (6) decimal places, they will round to three (3) decimal places when they are displayed, and any figures you enter will also be rounded to three (3) places when the results are displayed.
  • Piston Head Volume and Deck Clearance. Values for Piston Head Volume and Deck Clearance can be entered as both positive or negative values. Negative numbers indicate a reduction in cylinder head volume. Pistons with pop-ups or pistons sticking out above the deck will reduce chamber volume and will usually require a negative number. Pistons with a dish or pistons below deck increase chamber volume and receive a positive value. Located above each picture in the KB Catalog is the value for the piston head volume shown in positive or negative numbers.
  • Deck Clearance. Deck clearance should be measured from the top of the block to the flat portion of the piston. Do not measure to the top of the pop-up or the bottom of a dish. With some pistons this flat area may be very small (example: Chrysler Hemi is only a line at zero deck).
  • Gasket Bore. If you do not have the exact gasket bore use the cylinder bore in its place.
  • Piston Head Volume. On the piston calculator many times you will come up with a piston head volume that approaches zero. When this happens the valve reliefs and the pop-up are approximately equal in value.