Can someone explain to me and teach me what displacement means in a car?

Question

i want a thorough introduction to this from a very experienced mechanic or enthusiast

Answer 1

The pistons in an internal combustion engine travel up and down only.  The up-and-down travel distance times the piston area will give you a displacement volume.

A two liter engine will have 2000 cubic centimeters of displacement.  This amount divided by four pistons would be 500 cc of displacement per piston.  For a 10 cm diameter piston, you'd have about 78.5 cm2 of area on the surface.  The up and down travel distance on this piston would be about 6.4 cm (2.5 in) in order to generate the 2000 cc of displacement.

Note:  Vertical travel might be more on the average engine.  I tried to use some relatively easy numbers.

The engine shaft rotates with the pistons displacement.  This converts the vertical motion into a rotational motion.  This conversion allows the shaft to turn your car's wheels.

Answer 2

Displacement is the difference between the volume of the cylinder when the piston is all the way up (TDC) and when it is all the way down, multiplied by the number of cylinders in the engine.  Thus it is the theoretical maximum amount of air the engine pumps for every 2 revolutions.

Basically it is an indication of how powerful the engine is, because the larger the displacement the more air/fuel mixture it can burn per cycle.

  

Answer 3

Check out howstuffworks.com . Its a little complicated to answer.