The total volume of all the cylinders would be the cubic inch (cid) or cubic centimeter (cc) displacement of that particular engine.
engine
The "volume" of an engine (4.2 liters in this question) is the volume of the cylinders in which the explosions take place that generate the engine power.
This is the displacement of the engine. Or how much volume the engine will displace in one full cycle (compression and exhaust stroke for all the cylinders.) The measurement is cubic centimeters or cc.
The volume of an engine is called displacement and is typically measured in cubic inches or liters. An eight cylinder engine that could hold 1/2 liter of water (or air) in each cylinder would be a four liter engine. As the pistons move to the top of the cylinder in an exhaust stroke, they theoretically "displace" the 1/2 liter of air in each of the cylinders. The compression ratio is calculated during the compression stroke. If the piston occupies 90% of the enclosed cylinder space when it is at top dead center, the compression ratio is said to be 10 to 1, or 10:1. If the displacement of the cylinder was 10 cubic inches, it would have been compressed to 1 cubic inch.
Displacement
Total displacement, usually in cubic inches or liters.
The compression ratio of an internal-combustion engine, or an IC engine as it is more commonly called, is the ratio of the volume the highest capacity of the combustion chamber to its lowest capacity. In the IC engine, the piston makes a stroke, resulting in the compression of the air in the combustion chamber - the ratio between the volume of the cylinder and combustion chamber when the piston is at the bottom of its stroke, and the volume of the combustion chamber when the piston is at the top of its stroke, is the compression ratio.
The chamber volume refers to the compression ratio of the external combustion of the engine.
Calculate the volume of a single cylinder and multiply it by the number of cylinders.
Engine capacity is the total volume of the spaces each of the cylinders occupies.
Compression ratio is exclusive to each cylinder, though they will all have the same result if they are the same dimensionally ( and they always are) > Divide the total engine capacity by the number of cylinders, this gives the capacity or swept volume of each cylinder (bore * stroke) > So in a 2.0 (2000 cc) litre 4 cylinder engine, each cylinder has a 2000 / 4 = 500 cc swept volume (bore * stroke) > The combustion chamber is the volume remaining at top dead centre (TDC) > Compression ratio = volume at BDC (swept volume + volume at TDC) / volume at TDC
Compression Ratio is the ratio between the original volume and the compressed volume in combustion chamber. The compression ratio is denoted as CR. It is the measure of how much air-fuel mixture is compressed during the compression stroke in the case of the gasoline engine (in the case of the diesel engine only air is compressed. Compression ratio is found by dividing the volume of stroke of the cylinder (swept volume) and clearance volume when the piston is at BDC by the volume when the piston is at TDC (ie clearance volume). Compression ratio= (Swept volume + Clearance volume) / Clearance volume. For example engine has a Swept volume of 700 cc. It has clearance volume 50 cc. Compression ratio= (700 + 80) / 80 =9.75: 1 It means Air fuel mixture is compressed to 1/9.75 of its original volume during compression stroke.