Compression Ratio

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

The compression ratio in an engine is the ratio of the maximum volume to the minimum volume in a cylinder. The equation and calculator below can help find the compression ratio. 

Compression Ratio Formula

\(\large{ CR = 1 +  \frac{\pi}{4} * \frac { BORE^2 * STROKE } {CCV + HGV + PVD  }  }\) 

Where:

\(\large{ CR }\) = compression ratio

\(\large{ BORE }\) = bore

\(\large{ CCV }\) = combustion chamber volume

\(\large{ HGV }\) = head gasket volume

\(\large{ PDV }\) = piston deck volume

\(\large{ STROKE }\) = stroke length

Tags: Equations for Engines