Compression Ratio Calculator

Formula

The formula to calculate the Compression Ratio is:

\[ CR = \frac{(\frac{\pi}{4} \times b^2 \times s) + Vc}{Vc} \]

Where:

\(CR\) is the compression ratio
\(b\) is the cylinder bore diameter in mm
\(s\) is the stroke length in mm
\(Vc\) is the minimum clearance at the end of the compression stroke in mm³

Compression Ratio Definition

A compression ratio is defined as the ratio of total working volume to total compression volume. It is a critical parameter in engine design as it affects the engine's efficiency and performance.

Example Calculation 1

Let's assume the following values:

Cylinder Bore Diameter (b) = 80 mm
Stroke Length (s) = 90 mm
Minimum Clearance (Vc) = 50 mm³

Using the formula:

\[ CR = \frac{(\frac{\pi}{4} \times 80^2 \times 90) + 50}{50} = 9048.79 \]

The Compression Ratio is 9048.79.

Example Calculation 2

Let's assume the following values:

Cylinder Bore Diameter (b) = 100 mm
Stroke Length (s) = 110 mm
Minimum Clearance (Vc) = 60 mm³

Using the formula:

\[ CR = \frac{(\frac{\pi}{4} \times 100^2 \times 110) + 60}{60} = 14399.97 \]

The Compression Ratio is 14399.97.