How you can masure the piston ring side clearance?

To measure the piston ring side clearance, first, install the piston ring onto the piston and place them in the cylinder bore. Use a feeler gauge to measure the gap between the ends of the ring when it is positioned in the bore. The thickness of the feeler gauge that fits snugly in the gap indicates the side clearance. Ensure that the measurements are taken at multiple points for accuracy, as the clearance can vary due to wear or manufacturing tolerances.