| In a transmission, where all gears are constantly in contact and turning with one another. | |
| Enclosure formed by a pocket in the cylinder head at the top of the piston, where the spark plug ignites the compressed air/fuel mixture. The volume of the cylinder above the piston when the piston is at TDC top dead center. | |
| Parts equipment manufacturing that is not original equipment from the factory. | |
| Camshaft position sensor |