Cylinder head structure

摘要

The bottom surface 18 of the cylinder head 10 is formed by an intake-side bottom surface 18 a and an exhaust-side bottom surface 18 b on which an intake port 13 and an exhaust port 15 are formed respectively. Further, a first wall 19 formed between an intake-side water jacket 16 and the intake-side bottom surface 18 a is larger in thickness than a second wall 20 formed between an exhaust-side water jacket 17 and the exhaust-side bottom surface 18 b. This structure can reduce an amount of HC included in exhaust gas.