SPARK PLUGS

Technical information

Spark Plug Anatomy / Construction
Although the spark plug is a familiar engine component, spark plug terminology often varies. The diagram below identifies the major components of a spark plug and their correct terminology. ...
 

Resistor Spark Plugs
Resistor type spark plug’s incorporate an internal resistor to suppress ignition noise generated during sparking. The ignition noise which is often known as either electromagnetic interferenc...
 

Precious Metal Spark Plugs
NGK's range of precious metal spark plugs provide two major benefits over conventional spark plugs – high ignitability and long service life ...
 

Spark Plug Installation
Spark plugs are designed to operate at an optimal operating temperature and correct tightening is critical to the operation of a spark plug. Problems commonly occur if the incorrect torque is appli...
 

LPG Compatibility
When converting a vehicle from petrol to LPG there are two critical factors that need to be understood; LPG burns hotter and LPG increases the voltage requirement at the electrode gap   ...
 

Operating Temperature
The operating temperature of a spark plug varies between 450-870°C. ...
 

Heat Range Explanation
Typically the heat range for NGK Spark Plugs varies from 2-11. This number indicates the thermal characteristics of a spark plug, or how ‘hot’ or ‘cold’ a spark plug is. ...
 

Projection
The projection of a spark plug is measured as the distance from the end of the metal shell to the tip of the centre electrode ...
 

Electrode Gap
The electrode gap of a spark plug dictates the spark magnitude. An incorrect electrode gap may affect engine performance as the spark magnitude may be insufficient to ensure complete combustion of ...
 

Electrode Gap Adjustment
A variety of techniques are used to adjust electrode gaps. An appropriate method and tool should be used for gap adjustment although it has come to our attention that a variety of improper methods ...
 

Modified / Performance Engines
It is critical to note that once an ENGINE IS MODIFIED, THE RECOMMENDED SPARK PLUG listed in the NGK Spark Plug catalogue for that application MAY NO LONGER BE SUITABLE. ...
 

Spark Plug Analysis
Appearance of a used spark plug tells a lot about the operating conditions of the engine and the plug; the analysis of a plug plays an important role in the maintenance of a car. ...