Patent ID: 8191252

Claim:
A method for producing a cylinder head, comprising: providing a core which includes: an upper water jacket-forming core which is used to form an upper water jacket within a cylinder head; a lower water jacket-forming core which is used to form a lower water jacket within the cylinder head; and a core portion including a holding core portion and a distance maintaining core portion which is used to hold the upper water jacket-forming core and the lower water jacket forming core with a predetermined distance maintained between the upper water jacket-forming core and the lower water jacket forming core, said core portion connects an end portion of the holding core portion to a side end portion of the upper water jacket-forming core and a side end portion of the lower water jacket-forming core, and the core portion being split into two portions at the holding core portion; arranging an exhaust port-forming core between the upper water jacket-forming core and the lower water jacket-forming core using the core portion; and molding the cylinder head by pouring molten material into a die used to form the cylinder head with two split portions of the holding core portion held adjacent to each other.