Term describes a material that has a free electron.

This is the performance of an extremely thorough cleaning, polishing and waxing of an automobile, both inside and out, to produce a showroom-quality result.

The degree of darkness or lightness of a colour.

A control device that restricts or cuts off the flow of a liquid or gas.

A ball used to create a seal inside a valve.

Collection of valves in one unit that operate a common system (automatic transmission for example).

Bounce of a valve in its seat when closing. Usually occurs as a result of the engine speed being too high or the valve spring losing tension through age or deterioration.

The mechanism from a cam to a valve in an engine that transmits the movement of the cam to open the valve.

The tube or sleeve in the cylinder head that locates a valve centrally in its seat. The valve slides in the guide during opening and closing.

The top or disc end of a valve that seals the gases in the cylinder head.