Abstract: A spark plug orientation method may include forming a spark plug housing by advancing a tool a first distance in a first axial direction into a spark plug bore to create a spark plug seat using a seat forming portion of the tool. The tool may be displaced a second distance in a second axial direction generally opposite the first axial direction to provide a predetermined axial orientation between the thread forming portion of the tool and the spark plug seat. The spark plug bore may be engaged at a first predetermined rotational position and the tool may be displaced in an orbital motion and in the second axial direction at a predetermined rate to form a threading on the spark plug bore providing a starting point of the threading at a second predetermined rotational position proximate the spark plug seat.

Abstract: A method of manufacturing an engine includes providing an inventory of cylinder heads each having a first set of features and a first set of datums. The first set of features is spatially arranged relative to the first set of datums. A fixture that is apart from all of the cylinder heads is provided. The fixture has a second set of features spatially arranged relative to one another substantially identically as the first set of features are spatially arranged relative to one another. A cam carrier is secured to the fixture at the second set of features. A cam bore is machined in the cam carrier at a position determined relative to the second set of features and relative to a surface of the cam carrier that abuts the fixture.

Abstract: A system and method for identifying the start location of the lead thread and the thread profile and quality in a threaded bore in a part, where the system and method can be used for determining the location of the lead thread in a threaded bore in a cylinder head for a spark plug in one non-limiting embodiment. The system includes a moveable table on which the part is mounted. The system also includes a probe having an optical assembly that is inserted in the threaded bore. A camera uses the optical assembly to generate images of the thread bore, where the images are image slices as the probe moves through the threaded bore. The image slices are unwrapped and then joined together to form a planer image to determine a start location of the lead thread, thread count, defects in the threaded bore and thread profile parameters.

Abstract: A spark plug orientation method may include forming a spark plug housing by advancing a tool a first distance in a first axial direction into a spark plug bore to create a spark plug seat using a seat forming portion of the tool. The tool may be displaced a second distance in a second axial direction generally opposite the first axial direction to provide a predetermined axial orientation between the thread forming portion of the tool and the spark plug seat. The spark plug bore may be engaged at a first predetermined rotational position and the tool may be displaced in an orbital motion and in the second axial direction at a predetermined rate to form a threading on the spark plug bore providing a starting point of the threading at a second predetermined rotational position proximate the spark plug seat.

Abstract: A system and method for identifying the start location of the lead thread and the thread profile and quality in a threaded bore in a part, where the system and method can be used for determining the location of the lead thread in a threaded bore in a cylinder head for a spark plug in one non-limiting embodiment. The system includes a moveable table on which the part is mounted. The system also includes a probe having an optical assembly that is inserted in the threaded bore. A camera uses the optical assembly to generate images of the thread bore, where the images are image slices as the probe moves through the threaded bore. The image slices are unwrapped and then joined together to form a planer image to determine a start location of the lead thread, thread count, defects in the threaded bore and thread profile parameters.