Engine system

An engine system in which blow-by gas with a specific gravity less than 1 with reference to air is generatable, the engine system comprising:

• a cylinder block including a cylinder and a crank chamber which are arranged in an up/down direction, the crank chamber being positioned below the cylinder;
• an intake port configured to supply air to a combustion chamber;
• an injection unit configured to inject gaseous fuel into an internal space of the intake port;
• and
• a refrigerant passage through which a refrigerant is configured to pass,
• wherein the intake port and the refrigerant passage are physically separated by a first wall portion and a second wall portion that has a greater thickness between the intake port and the refrigerant passage than the first wall portion,
• wherein a central axis of an injection area of the gaseous fuel from the injection unit intersects the first wall portion,
• wherein an internal peripheral face of the cylinder block has a ventilation port that connects to a ventilation passage that connects an internal space of the crank chamber with an external space out of the cylinder block, and that is open, and
• wherein the ventilation port is placed above a center in the up/down direction in the crank chamber.