A camshaft assembly including a target wheel is manufactured using an assembly process in which the camshaft is formed from a hollow tube. After the cam rings and a target wheel ring have been correctly positioned on the hollow tube, the tube is pressurized to expand its diameter, locking the rings into position on the tube. Locating the target wheel along the axis of the camshaft and spaced from the camshaft end allows the sensor to be located along the axis of the camshaft, and precludes the need to increase the overall length of the head to accommodate the target wheel and the sensor. In a dual overhead engine, the target wheels may be mounted on the two camshafts so that they may be read by a dual element sensor that is mounted between the two wheels.