NGK SPARK PLUGS

NGK iridium spark plugs currently represent the highest-quality technological solution. They feature an iridium-alloy on the middle electrode. It is welded on in a special process using laser. The precious metal iridium starts melting at a temperature of 2450°C and is therefore very resistant to spark erosion. To sum things up, by using the iridium spark plug, the service life is doubled on average in comparison to standard nickel spark plugs.

These spark plugs are equipped with a platinum plate on the middle electrode. This ensures a more constant output of the spark plug over the entire service life, even under difficult conditions. Based on its narrow middle electrode, it emits very little spark voltage. Moreover it discharges the ignition coil, and ensures optimal combustion.

One strategy for extending the service life of a standard nickel spark plug is to equip it with multiple ground electrodes. With such spark plugs, the spark continually jumps over to a different ground electrode. In doing so, the wear is distributed to up to four ground electrodes and the service life is extended.

The principle of Niterra’s patented V-grooved spark plugs is technically simple but very effective. A V-groove is situated in the centre electrode. This forces the spark to occur at the outer edge of the centre electrode where it is easier to ignite the air-fuel mixture. In addition, the voltage required to produce a spark is reduced. These two features give the benefit of improved ignitability, even under extreme operating conditions.

These Niterras are equipped with a housing that is fit close to the insulator. If the insulator tip is clogged with carbon deposits, the spark voltage first flows down to the height of the fitted case. The jump to the case now represents lower resistance than flowing along the insulator. Therefore, an arc-over to the housing and thus the ignition of the air-fuel mixture occurs. As soon as the spark plug reaches the self-cleaning temperature of 450°C, carbon deposits are burned off. The spark can now reassume the normal path through the ground electrode.

In the event of a carbon deposit clogging on the insulator or the insulator being at temperatures below the self-cleaning temperature, semi-surface Niterras provide a reliable cold start. Because of this, they have at least two ground electrodes arranged on the side with a tapered point. The arc-over takes place from the tip of the middle electrode to the tip of one of the ground electrodes at the top end. By doing so, the spark initially creeps over the insulator tip. With this process, not only is the fuel-air mixture ignited; the insulator tip is also cleaned of carbon deposits with every spark.

Hybrid NGK spark plugs have a “normal” ground electrode as well as two smaller ground electrodes to the side. These spark plugs are developed for engines that tend towards increased carbon depositing as a result of their design. The side electrodes come into action if the spark plug is clogged with carbon. In this case, the ignition voltage flows down the clogged insulator, direction of the thread. It passes by an area where the side electrodes are very near. The resistance to the side electrodes is smaller than the resistance of the insulator. Therefore, the voltage jumps over to the side electrodes, enabling the spark plug to operate even under severe conditions. Once the plug has reached its operation temperature and the deposits are removed, it returns to “normal” operation: The spark jumps between the centre and main ground electrode.

NGK spark plugs used for racing must withstand especially hard stresses. The speeds during a race are frequently in excess of 15,000 rpm. Temperature, pressure, and vibrations in the combustion chamber are so immense that conventional ground electrodes could break or melt. For this reason, NGK racing spark plugs often come with specially designed ground electrodes. The most extreme form of these plugs come with a ring-shaped ground electrode. The spark jumps from the middle electrode to the ring-shaped ground electrode.

LPG LaserLine spark plugs are dual precious metal spark plugs specifically developed for gas-fuelled engines. The combustion of gas is different from the combustion of petrol. Therefore, it requires spark plugs which are specially adapted to these conditions. More ignition voltage is required. This is why the gas-air mixtures are more difficult to ignite. NGK LaserLine spark plugs come with a lifetime of 60,000 km, clearly outperforming “normal” spark plugs.

A spark plug’s basic function is to ignite the air-fuel mixture within the combustion chamber of a petrol engine. Spark plugs provide a path for electrical energy from the ignition coil to generate a spark needed for this air-fuel mixture. The quality of the ignition spark directly affects several factors for both the quality of the driving experience and the environment. These include starting, smooth running, general engine performance and efficiency as well as the reduction of harmful emissions. 
 

Symptoms of bad spark plugs include reduced fuel economy, rough idling, engine misfiring and difficulty starting the engine.
 

There are a variety of reasons why spark plugs fail. These include: old age (recommended replacement interval has been ignored), carbon build up, overheating, oil present in the combustion chamber and the incorrect spark gap.
 

A variety of different metals can be used in spark plugs. Almost all spark plugs feature a copper cored inner central electrode because copper is an excellent electrical conductor. Copper, however, is a very soft metal with low resistance which means that it is not suitable as an outer centre or ground electrode. Niterra’s standard range of plugs feature a nickel alloy outer centre electrode (fused to an inner copper core) and a nickel ground (side) electrode. The company’s premium range features extremely hard metals like iridium and platinum which guarantee longer replacement intervals.
 

This depends on a range of conditions such as the engine’s condition, if the plugs were correctly installed, the type of metal present on the plug’s outer centre and ground electrodes etc. Generally, the driver or rider should refer to the maintenance intervals recommended by the manufacturer. In this context standard nickel spark plugs need to be replaced earlier than precious metal spark plug types that are more resistant with regards to wear.
 

It is absolutely necessary to tighten a spark plug to the specified turning angle or torque setting. If the torque is set too low, there is a risk of compression loss. Additionally, the insulator and electrodes may also be damaged as a result of excessive vibrations. If the torque is set too high, however, the metal shell of the spark plug will be over-stressed, increasing the likelihood of it yielding or expanding. Expansion can cause the heat dissipation zones to be disrupted. Overheating, melting of the electrodes and even engine damage are other potential outcomes.
 

Common reasons for this include the wrong spark plug heat range, a non-optimal engine combustion process and poor running conditions like continuous low-speed driving and short trips. A spark plug must reach a temperature of 450°C before it starts to self-clean by burning off carbon deposits. Regular short trips and continuous low-speed driving, however, result in the spark plug being unable to reach this critical temperature, making conditions for fouling ripe.
 

This depends on the type of engine being used. Low power engines such as lawnmowers and chainsaws don’t produce large amounts of heat, meaning that a ‘hot’ spark plug (with a low heat range) is needed to reach optimum performance temperature. High-performance engines, however, generate a large amount of heat, resulting in the requirement for a ‘cold’ spark plug (with a high heat range). The heat range number, which typically varies between 5-10, is featured within a spark plug’s code (found on the ceramic insulator). This number illustrates how ‘hot’ or ‘cold’ the particular plug in question is. The lower the number (e.g., 5 or 6), the hotter a spark plug is, whereas the higher the number (e.g., 9 or 10), the colder the spark plug is.
 

No, spark plugs come in a variety of sizes, satisfying the needs of all types of engines such as smaller ones used in lawnmowers and chainsaws. It is very important never to take a ‘one size fits all’ approach. Afterall, Niterra manufactures well over 1,000 different spark plugs for cars alone, with each car having its own particular spark plug specifications. The company’s catalogues or online part finder are useful tools to identify an engine’s correct plug.