What is compression ratio (in motor engine),& wich ratio is best ratio.?
The compression ratio is dependent on your engine. It is the ratio of the volume in the cylinder when the piston is at the bottom-dead-center (highest volume) to the volume in the cylinder when the piston is at the top-dead-center (lowest volume). comp ratio = highest cylinder volume/ lowest cylinder volume If you understand the basics of how an engine works you will know that the piston moves up and down as the engine rotates the crankshaft. As the piston moves down the intake valve opens and draws a mixture of fresh air and fuel into the cylinder. The valve then closes and and the pistion moves up. Since the air can’t go anywhere it is compressed. At somewhere near top-dead-center (the point when the air is the most compressed) the spark plug fires and and the air/fuel mixture combusts and forces the cylinder down. This is what powers your car. The compression ration is dependent on the bore cylinder and the throw of the piston. Generally a higher compression ratio is desireable for
