Spark plug
A spark plug also known as a "sparking plug", is a device used in delivering the electric current to the air-fuel mixture in the combustion chamber in an internal combustion engine. It us connected to the ignition coil and as the electricity flows through the coil, a voltage difference develops between the electrodes on the spark plug. This causes electricity to jump the gap, making a spark which ignites fuel.
Spark Plug Media
Spark plug with single side electrode
An electric spark on the spark plug
Components of a typical, four stroke cycle, DOHC piston engine.- (E) Exhaust camshaft*
- (I) Intake camshaft*
- (S) Spark plug*
- (V) Valves*
- (P) Piston*
- (R) Connecting rod*
- (C) Crankshaft*
- (W) Water jacket for coolant flow*
Two spark plugs in comparison views in multiple angles, one of which is consumed regularly, while the other has the insulating ceramic broken and the central electrode shortened, due to manufacturing defects and / or temperature swing
Central and lateral electrodes
Gap gauge: A disk with a tapered edge; the edge is thicker going counter-clockwise, and a spark plug will be hooked along the edge to check the gap.
Spark plug with two side (ground) electrodes
Different spark plug sizes.*The left and right plug are identical in threading, electrodes, tip protrusion, and heat range. The centre plug is a compact variant, with smaller hex and porcelain portions outside the head, to be used where space is limited. The rightmost plug has a longer threaded portion, to be used in a thicker cylinder head.
