Engine cooling system including cooled exhaust seats

A cooling system for a cylinder head of an internal combustion engine, comprising:

• a cylindrical seat configured to engage an exhaust valve, the cylindrical seat defining an annular cooling passage extending along a circumference of the cylindrical seat, a wall of the cylindrical seat defining a first opening into the annular cooling passage;
• a first coolant jacket disposed entirely above a combustion chamber;
• and
• a first conduit fluidly coupling the first coolant jacket to the first opening.

A method, comprising:

• providing a cylinder head of an internal combustion engine, the cylinder head comprising a cylindrical seat configured to engage an exhaust valve, the cylindrical seat defining an annular cooling passage extending along a circumference of the cylindrical seat;
• positioning a first coolant jacket disposed entirely in the cylinder head;
• fluidly coupling the first coolant jacket to the annular cooling passage via a first conduit;
• positioning a second coolant jacket disposed entirely above in the cylinder head;
• and
• fluidly coupling the second coolant jacket to the annular cooling passage via a second conduit,
• wherein the annular cooling passage is configured to receive a coolant for cooling the cylinder head.