1800cc's of displacement. In all the cylinders there is 1.8l's of space. Basically the bigger the engine, the more fuel and air you can fit in which equals a bigger boom and more power. There is alot of other physics to it, but that is the jist of it. Some smaller displacement engines make more power then a engine that is bigger, this is where the physics and design come in.
85 325 - Turbo M52B28.