- an electrical device threaded into the cylinder of an internal-combustion engine to ignite the fuel mixture by producing timed sparks between electrodes
- Informal a person or thing that inspires, activates, or advances something
- A device inserted in the head of an internal-combustion engine cylinder that ignites the fuel mixture by means of an electric spark.
- Informal One who gives life or energy to an endeavor.
B. ceramic insulation
C. center electrode
E. ground electrode
(plural spark plugs)
- The part of an internal combustion engine which forms a high-voltage electric spark which ignites the fuel-air mixture to begin the power stroke.
- The spark plug is quite simple in theory: It forces electricity to arc across a gap, just like a bolt of lightning. The electricity must be at a very high voltage in order to travel across the gap and create a good spark. Voltage at the spark plug can be anywhere from 40,000 to 100,000 volts.