Glossary “spark plug well” Definition:
Recess in a cylinder head for a spark plug.

Glossary “spark plug deposit test” Definition:
Visual inpection of spark plugs to see if the engine is using oil.

Glossary “spark plug fouling” Definition:
An accumulation of deposits on the lower, exposed end of the spark plug that act as an electrical conductor, thereby creating a path for electricity to travel to ground, rather than jump across the electrode gap.

Glossary “spark plug heat range” Definition:
The temperature limits, hot, normal, or cold, within which a spark plug is designed to operate. It is determined by varying the length of the exposed lower section of the plug ceramic insulator.

Glossary “spark line” Definition:
The line on an oscilloscope that indicates the voltage required to fire the spark plug and the number of degrees the distributor turns while the spark exists.

Glossary “Spark Output” Definition:
Ford SPOUT. The output signal from the processor which triggers (signals) the ignition module to fire the ignition coil.

Glossary “spark plug” Definition:
An ignition component threaded into the cylinder head that contains two electrodes extending into the cylinder that form a gap across which high-voltage electricity arcs to ignite the compressed A/F mixture.

Glossary “spark delay valve (SDV)” Definition:
A vacuum valve acting like a restrictor, used in the vacuum line between the distributor and carburetor, to delay vacuum-timing advance under certain driving conditions to reduce NOx emissions.

Glossary “spark duration” Definition:
The time a spark is established across the gap of a spark plug.

Glossary “spark ignition (SI)” Definition:
An engine-operating system where the air/fuel mixture is ignited by an electrical spark.

Glossary “spark knock” Definition:
Term used for detonation or ping. Secondary rapid burning of the A/F mixture in the combustion chamber causing a second flame front that collides with the first flame front and produces a engine knock.

Glossary “spark lighter” Definition:
Device that produces a spark and ignites an oxyacetylene torch.

Glossary “spark amplitude” Definition:
The greatest voltage created during a spark event ( the hight of the firing line )

Glossary “spark decel valve” Definition:
A vacuum valve, located in the line between the distributor and carburetor, to advance the spark during deceleration, to reduce emissions.

Glossary “spark advance” Definition:
The moving ahead or advancement of the ignition spark in relation to the piston position.

Glossary “spark advance curve” Definition:
The rate at which ignition timing advances as plotted on a graph; the line rises from some initial amount of advance and levels off at the maximum advance.