What does cubic capacity of engine indicates?

CC's (cubic centimeters) or Cu.In. (in3) (Cubic Inches) of displacement =

The amount of VOLUME in the cylinders, from the top of the piston to the bottom of the cylinder head, when the piston is at it's lowest point allowed by the crankshaft.

The "cubes" are the total volume of ALL of the engine's cylinders. For example, a Chevy 350 (5.7L) has 350 cubic inches of cylinder displacement including all 8 cylinders. So, divided by 8, each cylinder would be 43.75in3.

The easiest way to measure would be to just look it up in the engine's service manual specifications. OR, if for some reason you needed to measure the engine's actual cylinder displacement in real life, you could use oil or water (I'd recommend using oil) dump it into the cylinder through either the spark plug hole or the injector hole and measure it. (Be sure the piston is all the way down and that both the intake and exhaust valves are closed when you do that test!)

Kudos! ~AJ