Abstract: An apparatus for measuring pressure comprises a housing and an actuator pressure sealed to the housing and having a shaft. The actuator is configured to be in pressure communication with a volume of gas or liquid. Upon a change in pressure, the actuator is displaced at least partially in the axial direction. A sensor detects axial displacement of a magnetically encoded target upon the change in pressure in the volume. A device for measuring pressure in an engine cylinder comprises a valve in pressure communication with an engine cylinder. The valve stem has a magnetic coding located adjacent a sensor. Axial displacement of the stem under cylinder pressure is detected and pressure is obtained.

Abstract: A cylinder head (10) for an internal combustion engine has hydroformed port liners (18) positioned within selected ports, either exhaust and/or intake ports (14, 16). The hydroformed port liner (18) includes an air gap (24) for an insulation layer within the selected port (14, 16) between an outer surface (19) of the hydroformed port liner (18) and the wall of the port (14, 16). A cylinder head (12) with a predetermined port configuration has selected ports (14, 16) cast with protrusions (22). The selected ports (14,16) have a larger diameter than a standard size port diameter for that cylinder head to provide a predetermined port configuration by a preset amount based on the thickness of the hydroformed port liner (18) and a desired air gap (22). Protrusions (22) in the wall of the selected ports (14, 16) or on the insert sleeves (17) facilitate formation of the air gap during the hydroforming process.