Cylinder head and engine

Abstract

To find compromises in the relationship between the component costs of intake and exhaust valves and the downsizing of an engine and the relationship between the cooling performance and the followability of the intake and exhaust valves and coordinate these conflicting relationships as much as possible. A hollow valve encapsulating coolant having a good cooling function is used as an exhaust valve, which is exposed to a higher temperature environment than an the intake valve, to eliminate a disincentive to downsizing. In contrast, a hollow valve that has no coolant, relatively low component cost, light weight, and good followability is used as the intake valve, which does not need to have a better cooling function than the exhaust valve and needs to have better followability than the exhaust valve to improve combustion efficiency.

Dependencies are inferred from the claim text.