Enter the block height, crank stroke, rod length, and deck clearance into the compression height calculator. The calculator will evaluate and display the compression height. This calculator can also calculate any of the values in the formula below given the other variables are known.

Compression Height Formula

The following formula is used to calculate the compression height of a piston. 

CH = BH - .5*CS - RL - DC
  • Where CH is the compression height
  • BH is the block height
  • CS is the crank stroke
  • RL is the rod length
  • DC is the deck clearance

To calculate the height compression, subtract 1/2 of the crank stroke, the rod length, and deck clearance from the block height.

What is a compression height?

Definition:

A compression height is a term used in automotive engineering to describe the distance between the center of the wrist pin to the crown of a piston.

The compression height is a key component in building performance engines in order to get the desired quench.

How to calculate compression height?

Example Problem:

The following example problem outlines how to calculate the compression height of a combustion engine. Keep in mind these dimensions in this example problem may not be realistic, they are only for showing the process of calculation.

First, determine the block height. For this example, the block height is measured to be 6 inches.

Next, determine the distance of the crank stroke. The crank stroke for this example is 3 inches.

Next, determine the rod length. The rod length for this engine is measured to be 1.5 inches.

Next, determine the deck clearing. For this engine, the deck clearance is 2 inches.

Finally, calculate the compression height using the formula above:

CH = BH – .5*CS – RL – DC

CH = 6- .5*3 – 1.5 – 2

CH = 1 inch