Multi-cylinder internal combustion engine

A multi-cylinder internal combustion engine provided, on the downside of a cylinder block, with a communicating passage configured by an upper crankcase integrated with the cylinder block or provided separately from the cylinder block and a lower crankcase connected to a lower part of the upper crankcase for communicating with an internal space of a plurality of crank chambers corresponding to a plurality of cylinders, the multi-cylinder internal combustion engine comprising:

• a communicating hole that is provided at least on either side of the upper crankcase or the lower crankcase for communicating with the communicating passage;
• a cover for forming the communicating passage, said cover being arranged with the cover covering the communicating hole;
• and
• the cover is attached to both the upper and lower crankcases across a joined plane of the upper crankcase and the lower crankcase,
• wherein a groove for arranging a sealing member is formed on a surface joined to the crankcase of the cover;
• and
• each joining surface of the other upper and lower crankcases is flatly formed,
• the communicating passage is formed in the shape of a large bowl with the communicating passage covering the communicating hole in a front view;
• and
• the space for the communicating passage is configured by an inside face of the cover and the front of the crankcase,
• wherein the communicating passage includes multiple communicating passages formed in order along the cylinder block.