About the spark plug clearance and not only

Car candles - this is an important part of the car, providing the ignition of a certain amount of fuel, compressed piston. Under the influence of micro explosion, the piston moves, ensuring the motion of the crankshaft. Spark plugs are used only in gasoline engines. Here you need to set fire to fuel because of the piston pressure of 10-12 atmospheres. In the pistons of diesel engines, the pressure reaches 15-25 atmospheres, and the ignition is obtained due to the compression force.

The spark plug works under very extreme conditions - in the combustion chamber the temperature can fluctuate from 70 to 2500 C, the electrical voltage reaches 35-40 kW, the pressure reaches 55 atm. And the cycle of these impacts on the candle reaches 50 times per second. Therefore, the spark plugs are considered replaceable elements and, depending on the type of motor, are to be replaced after approximately 30 thousand km, and for reinforced engines - after 15-20 thousand km.

The spark plug in the generalized form consists of a body, a resistor, a central and side electrode, the distance between which is defined as the spark plug gap. Some models have several side electrodes, and more expensive options do not have them at all. Instead of them, additional electrodes on the insulator are present in the candle. In severe operating conditions, the electrodes gradually burn out, and the spark plug clearance increases, which leads to incorrect engine operation. In order for this moment to come as late as possible, it is important to correctly select the spark plugs.

When choosing spark plugs for your car, you should follow the data specified in the passport to the car, or use candles that are suitable for replacement. It is not forbidden to select these details depending on the style of driving. If the driver travels with frequent stops, the "hot" candle will suit, and if he prefers a more sporty driving style, then it is more "cold". The "hotness" of the candle is determined by the glow number - the higher it is, the colder the candle, because A large glow number implies a low temperature in the thermal cone of the insulator.

Without a good work of automobile candles, a good engine performance is impossible. Therefore, if there are breakdowns in his work or the machine does not start - it makes sense to pay attention primarily to the candles.

Visually, you can determine how suitable a candle is for an engine or type of ride. If an oiled black deposit is present on the insulator and electrodes, the candle is "cold" for this engine, if the carbon is black, but dry, the candle works normally on excessively rich mixtures. In the case of burnt-out electrodes or aluminum droplets, we can say that there is a glow ignition - the mixture ignites not from a spark, but from heated surfaces.

Check of spark plugs can be made:

• By checking for a "spark" (using a piezoelectric pistol, a bench with a pressure chamber or a diagnostic tester);
• By checking the electrical circuits;
• With the help of visual inspection.

Visual inspection is carried out after cleaning the candles from the deposit. To do this, the part is soaked in a solvent, washed, dried, and then inspect the thermal case for cracks and chips and the spark plug clearance to assess its correct size. This characteristic like the spark plug clearance is set for the candle in the factory and is not subject to further change.

Measurement of the gap is made with the help of a round feeler, and if you see an excessive increase, you can try to return it to the required parameters by tapping along the side electrode, without touching the central electrode. If you do not adjust the gap, you must immediately replace the spark plug with a new one in order to avoid more serious car breakdowns.