A valve is constructed to strike a balance between providing relatively high sealing yet low friction as components of the valve move. The valve includes a port and an actuator movable relative to the port. A member is disposed between the port and the actuator. The actuator acts on the member so that it can intermittently seal the port as it moves. The member and the actuator have a substantially low friction interface, whereas the seal member and the port have a substantially high sealing interface. The valve can be used in an engine, such as a rotary valve in an internal combustion engine.
