Are Diesel engines constructed differently, so that they have a higher stroke volume? (longer stroke, smaller combustion chamber etc.) I know the main differences between Diesel and Gasoline engines(fuel injection - spark plug etc.), but i can't get it in my head why Diesel engines have a higher compression ratio. Is it because they are designed different to have a greater volume?

Let's ask my question in a different way: What do you need to change of the parts in the engine to create a certain compression ratio? Which constructional factors do have influence on the compression ratio?