Cylinder head

A cylinder head for an internal combustion engine comprising:

• a combustion chamber recess formed on a lower surface of the cylinder head;
• an exhaust port including a downstream side channel and an upstream side channel, the downstream side channel having an open end at a side surface of the cylinder head and another end sealed by a bottom wall formed inside the cylinder head, the upstream side channel including an end that opens to the combustion chamber recess and another end connected to a side portion of the downstream side channel;
• a downstream side liner including a generally tubular member having a linear axis and inserted from the open end of the downstream side channel and positioned such that an edge of an insertion end of the downstream side liner abuts the bottom wall, the downstream side liner having a connecting hole in a side portion facing the upstream side channel;
• and
• an upstream side liner including a generally tubular member and inserted from the end of the upstream side channel that opens to the combustion chamber recess such that the upstream side liner engages with the connecting hole of the downstream side liner.