ENGINE

An engine () including a main fuel injection valve (), a pilot fuel injection valve (), a liquid fuel supply rail pipe (), and a pilot fuel supply rail pipe (). The main fuel injection valve () supplies liquid fuel from the liquid fuel supply rail pipe () to a combustion chamber () during combustion in a diffusion combustion system. The pilot fuel injection valve () supplies pilot fuel from the pilot fuel supply rail pipe () to the combustion chamber () in order to ignite gaseous fuel during combustion in a premixed combustion system. The liquid fuel supply rail pipe () is disposed at one side of an imaginary vertical plane (P) including an axis of a crank shaft. The pilot fuel supply rail pipe () is disposed at the side of the imaginary vertical plane (P) at which the liquid fuel supply rail pipe () is disposed.