Displacement refers to the total volume swept by all the pistons in the engine during one complete combustion cycle. It's typically expressed in units of liters or cubic centimeters.
For example, if an engine has a piston displacement of 4.6 liters, it means that the combined volume of all the cylinders when the pistons move from the bottom of their stroke to the top of their stroke is 4.6 liters.
The term "4.6 size engine" is often used in the context of automotive or industrial engines, particularly in reference to internal combustion engines powered by gasoline or diesel. The numerical value (4.6 in this case) provides a general indication of the engine's size and power output, although other factors such as the number of cylinders, engine design, and specific engineering features also influence the engine's overall performance and characteristics.
