tappet
/ˈtapɪt
/noun
A moving part in a machine which transmits motion in a straight line between a cam and another part.The 16-valve has twin, chain-driven, overhead camshafts and hydraulic tappets, while the 8-valve format uses a single camshaft....
- Contact between the cams and the tappets in the valve train span the mixed and boundary regions.
- The real breakthrough in lifter design for street and moderate competition applications was the marriage of roller tappets with hydraulic lifters.
Origin
Mid 18th century: apparently an irregular diminutive of tap2.