The present invention has an object to provide a vertical multi-cylinder diesel engine capable of conveniently protecting a common rail and its parts.
On the assumption that a width direction of a cylinder block (2) is taken as a horizontal direction, when arranging the common rail (3) horizontally lateral of the cylinder block (2), there is disposed above the common rail (3) a passage forming means (23) which is the alternative of an intake air distributing means (5) and an exhaust air converging means (22). The passage forming means (23) above the common rail (3) may be formed into a box-shaped structure with no branch pipe. Further, an engine cooling fan (4) may be arranged in front of the common rail (3) so as to pass cooling air below the passage forming means (23) above the common rail (3).