Compression Ratio Calculator
Instructions: Enter a value in the un-shaded boxes below as they pertain to your engine.
Note: For pistons BELOW the block @ TDC - value in box must be a POSITIVE number (.000)
Note: For pistons ABOVE the block @ TDC - value in box must be a NEGATIVE number (-.000)
Note: For a DISH piston - value in box must be a POSITIVE number (0.0)
Note: For a DOME piston - value in box must be a NEGATIVE number (-0.0)
Note: Manipulate the DOME/DISH & PISTON to DECK volumes to get the ratio you want.

Enter the number of cylinders of your engine
>
Bore
>
 Finished bore of your engine
>
Stroke
>
 Stroke of your engines crankshaft
>
Rod Length
>
 Ctr. to Ctr. length of your connecting rods
>
Gasket Bore
>
 Head Gasket bore diameter
>
Comp. Gasket
>
 Compressed Head Gasket thickness
>
Block Deck Height
>
 Center of main bearing bore to top of block
>
Top Ring Down
>
 Top of 1st ring to top of pistons (FLAT)
>
Chamber Volume
>
 Cylinder Head chamber volume in CC's
>
Dome/Dish Volume
>
 DOME (-) or DISH (+) vol. (theoretical) in CC's
>
Piston to Deck
>
 Top of BLOCK to top of piston (FLAT) @ TDC
>
Click "Calculate" for dimension results.
Total Volume
>
 
>
Cylinder Volume
>
Total cylinder volume in CC's =
>
Clearance Volume
>
All effective vol. above block deck @ TDC in CC's =
>
Gasket Volume
>
Volume of your head gasket in CC's =
>
Top Ring Volume
>
Total volume above the top ring @ TDC in CC's =
>
Deck Volume
>
Volume of area above the pistons @ TDC in CC's =
>
Piston Top Land
>
Piston top land diameter for volume calculations =
>
1/2 Stroke
>
1/2 stroke of your engine's crankshaft in inches =
>
Compression Ht.
>
Ctr. of piston pin to top of piston (FLAT) in inches =
>
Cubic Inches
>
Cubic inch displacement of your engine =
>
For the given dimensions, your compression ratio =
>

If you are having problems computing your compression ratio, please refer to the "notes" on top
and re-check your numbers or please call tech assistance.