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Spark plug

Spark plugs replaced during routine maintenance.

If you have to ever replace the spark plug is not in the routine maintenance, you should take the following into consideration.

Plugs and plug the whole system as a whole matched to this engine, and it reduces the amount of harmful substances in exhaust gases. To avoid failure in the engine, reducing its capacity, worsening pickup, increasing the content of harmful substances in exhaust gases and the creation of harmful interference to radio should be used only approved Volkswagen spark plug for the engine. Especially important characteristics of candles are the number of electrodes, heat rating and in some cases, the ability to not interfere with the radio.

There are two types of packing when installed in the cylinder head: a flat seat and elastic (steel or copper-asbestos) or seal with a conical seat without padding. When installing a new spark is first necessary to verify a seal is provided in the cylinder head and the diameter and length of the threaded portion. If you set a candle with a long threaded portion in the head with a short thread, the protruding portion candles covered with soot and tar deposits lead. The candle will overheat, possibly melting thread. When releasing candles are due to this damage the threads in the cylinder head. If the short threaded part of the spark in the head and long soot and various deposits clog the thread, there is its fusion. After a long work has to go tap a threaded portion in the cylinder head, but so that no dirt remains in the cylinder.

Depending on the purpose of the candles have a number of design features. So, for cars and motorcycles, heavy traffic conditions, when possible ingress of water on the engine, and increased requirements to the level of interference, use shielded candles with hermetic sealing high voltage wires. In order to improve the stability of the candles on the case sometimes made several electrodes or side electrodes do not (floating electrode).

Depending on the particular workflow candles made with recessed inside the body with a protruding insulator or an insulator (for combustion chambers with an intensive turbolizatsiey mixture in the combustion chamber).

The most important parameter characterizing a candle, a temperature mode of its elements, in the first place - the center electrode and the surface of the insulator.

The main problem in creating a spark for the high-speed engine is the implementation of conflicting demands. On the one hand - to provide sufficient heat shed that during prolonged operation at low load and idling to prevent the formation of soot on it, which leads to bypass, especially at low temperatures. In the transition to heavy loads at high temperatures the self-cleaning insulator candles burn fat at the expense of it.

On the other hand, at high speeds and high load the temperature of the central electrode and the lower part of the insulator should not exceed the upper limit at which there is surface ignition (ignition of the mixture before the spark ignition system). From cycle to cycle ignition occurs earlier and earlier, the temperature rising parts as long as that is not burned - in the best case, a candle, in the worst - the piston. So because of the small candles can be in big trouble.

How to prevent the possibility of pre-ignition? First of all, you need to follow the right (under the instruction) by setting the ignition timing angles, avoiding too early ignition. When the contact system ignition timing can suddenly increase, for example, if one of soldered bounce breaker contacts.

The second condition - always pour gasoline corresponding level forcing the engine (compression ratio, rated speed, content and others.). The lower the octane number, the greater the propensity for surface ignition. Well, if you still flooded with low-octane gasoline, you can not go for heavy loads at high rotational speeds.

The third condition, sometimes the most important thing - to install a candle to the desired heat range as recommended by the engine manufacturer.

The most convenient designation of glow, at one time taken by the majority of European companies, by the time (in seconds), after which when tested on a special installation begins surface ignition. In recent years, most companies switched to the symbol glow of candles.