NGK Spark Plug - Standard

SPARK PLUG TECHNOLOGY

The humble spark plug has undergone a number of changes over recent years to accommodate the demanding operating conditions required by modern engines.

Changes in Spark plugs have been caused by demands for longer life and also improved ignitability in today's lean burning modern engines.

It is critical that each cylinder fires to prevent unburnt fuel from reaching the catalytic converter and causing damage.

With engine manufacturers striving to lean off engines to improve fuel consumption the possibility of misfire becomes a problem.

It has been proven that a very thin electrode will improve ignitability, however a thin electrode made from nickel would quickly erode and fail, therefore spark plug 
manufacturers have necessarily turned to precious metals to withstand the harsh environment.

The introduction of precious metals to withstand the harsh environment.

The introduction of precious metals like platinum and iridium gave spark plugs the added benefit of long life. It is important to note that spark plugs are consumable with a limited service life and as such must be changed at regular intervals.

NGK Spark Plugs designed and Patented V-Groove Spark Plugs for improving ignitability in nickel alloy electrodes.

This style of spark plug incorporates a 90 degree V Groove in the centre electrode and ensures that sparking occurs at the periphery of the electrode, thus enhancing 
ignitability.

All modern engines require the use of resistor type spark plugs.

A resistor type spark plug is one that incorporates a 5 K ohm resistor to suppress ignition noise generated during sparking. (Radio frequency interference).

Radio frequency interference is commonly exhibited by the crackle sound coming from the car radio and there is now an Australian Standard covering R.F.I. which is considered
a type of pollution.

As R.F.I. can also cause premature failure to other electronic components in a modern vehicle, it is important that resistor spark plugs are used to prevent this possibility.

As stated earlier, the use of precious metals in spark plugs has increased their service life.

The following matrix gives an example of the characteristics and service life of resistor spark plugs when used in a modern unleaded engine:

*NGK Spark Plugs are designed to OEM requirements and as such, a variant of each of the above styles may not be available as it may not be an OEM requirement.
**Please note that the service life is provided as a general guide and may vary due to vehicle driving conditions.

The use of Iridium spark plugs is only just starting with Japanese car manufacturers who are finding them ideal for very low emission engines.

Heat range selection is vital to ensure optimum performance of spark plugs.

A spark plug's optimum operating temperature is between 450 degrees C and 870 degrees C. Spark plug tip temperatures outside this range can occur when an incorrect heat rating is selected. Viz:

When the heat rating is too high:

The spark plug temperature remains too low and causes deposits to build up on the firing end; the deposits offer an electrical leakage path that gives rise to loss of sparks.

When the heat rating is too low:

The spark plug temperature rises too high and induces abnormal combustion (pre-ignition): this leads to melting of the spark plug electrodes as well as piston seizure and erosion.

NGK Spark Plugs pioneered the use of a copper cored electrode in 1958, which enables a spark plug to heat up quickly and also dissipate heat quickly giving an ultra wide heat range. It is essential to use a spark plug that fits a specific engine and its conditions of use.

As spark plugs are positioned in the head of an engine, their analysis can give a good indication of how your engine is operating.

NGK Standard plugs for Scorpa, GasGas and Sherco BP5ES