Cooling system for an internal combustion engine

A cooling system for an internal combustion engine having at least two cylinder rows each having a set of cylinder heads and a set of cylinder blocks, the cooling system comprising:

• a coolant radiator system;
• a head coolant circuit including a head coolant inlet and a head coolant outlet for each cylinder row and a head thermostat valve for controlling a flow of coolant from the head coolant outlets of the cylinder rows, through one of or both the coolant radiator system and a bypass around the coolant radiator system, and to the head coolant inlets of the cylinder rows;
• a block coolant circuit including a block coolant inlet and a block coolant outlet for each cylinder row and a block thermostat valve for controlling a flow of coolant from the block coolant outlets of the cylinder rows, through one of or both the coolant radiator system and a bypass around the coolant radiator system, and to the block coolant inlets of the cylinder rows;
• wherein, for each coolant circuit, one of the coolant outlets is directly connected to an inlet of the coolant radiator system and another of the coolant outlets is directly connected to a bypass inlet of the thermostat valve;
• and
• wherein, for at least one of the coolant circuits, an intermediate line connects at least two of the coolant outlets.