What is the Compression Ratio of a four cylinder engine with a total volume of 9600cc, bore area of 100 cm² and a crank throw of 10 cm?

To determine the compression ratio of a four-cylinder engine, it is necessary to consider both the swept volume and the clearance volume, which together make up the total volume. The swept volume can be calculated from the displacement of the cylinders, which is typically given for the engine as a whole. In this case, the total volume is provided as 9600 cc, which represents the combined displacement of all cylinders when the pistons are at their lowest point (BDC - Bottom Dead Center).

The swept volume per cylinder can be calculated as follows:

1. The total volume (or displacement) is divided by the number of cylinders.

2. That means each cylinder has a volume of 2400 cc (9600 cc / 4).

Next, to find the clearance volume, which is the volume remaining in each cylinder when the piston is at the top dead center (TDC), we can use the stroke length derived from the crank throw. The stroke length (or distance the piston travels) is twice the crank throw, resulting in a stroke of 20 cm.

Using these values, the swept volume for each cylinder can be derived from the formula for cylinder volume:

Swept Volume (V_s) = π/4 × bore² ×