Internal combustion engine

An internal combustion engine, comprising:

• cylinders;
• a cylinder head that includes a pair of intake ports and a pair of exhaust ports for each of the cylinders;
• and
• a cylinder block that includes a block-side coolant passage, wherein
• the cylinder head is configured to allow coolant to flow from the block-side coolant passage into the cylinder head,
• one of the pair of intake ports and the pair of exhaust ports is a pair of specified ports,
• the cylinder head includes an inter-port coolant passage between the specified ports, wherein in the inter-port coolant passage, the coolant flows inward in a radial direction with respect to a central axis of each of the cylinders,
• the inter-port coolant passage is connected to the block-side coolant passage through a communication portion,
• a flow direction is a direction in which the coolant flows in a portion of the block-side coolant passage that is connected to the communication portion, and
• a center of a passage cross section of the communication portion is shifted to a downstream side in the flow direction with respect to a center of a passage cross section of the inter-port coolant passage.