The spark plug is one of the main parts of a gasoline engine. The clearance of candles, their quality and degree of pollution directly affect the stability and efficiency of the engine. A stable spark reveals the potential of ICE due to the fact that the fuel-air mixture burns out completely, increasing efficiency. An important role is played by the correct clearance of the candles, which determines how the car will go.
What is the correct clearance for spark plugs
The design of the candles provides a central electrode, to which voltage is applied. A spark forms between the central and side electrodes, and there is a gap between them. With a large gap, the engine is unstable, knocking occurs, tripling begins. With a small gap, the voltage on the candles sags up to 7 kilovolts, because of this the candle is overgrown with soot.
The classic engine operation is to supply a fuel-air mixture to the cylinders, where due to the upward movement of the piston, the necessary pressure is generated for ignition. At the end of the compression stroke, a high-voltage current comes to the candle, which is enough to ignite the mixture.
The average value of the gap is 1 mm, respectively, a deviation of 0.1 mm significantly affects the ignition for the worse or for the better. Even expensive candles require initial setup, as the factory clearance may initially be incorrect.
If the gap is larger than necessary, the spark power will be weak, part of the fuel will burn out in the resonator, and as a result, burnout of the exhaust system. The new product may initially have a different distance between the electrodes, and after a certain mileage the gap is lost and requires adjustment. An arc is generated between the electrodes, which contributes to their gradual burnout, which is why during the operation of the internal combustion engine the distance between the electrodes increases. When the motor is unstable, power decreases and fuel consumption increases - check the gaps, this is where 90% of the problems lie.
The clearance is important for the insulator. It protects the bottom contact from breakdown. With a large gap, the spark looks for a short way, so the probability of breakdown is high, which leads to the failure of the candles. The likelihood of soot formation is also high, so once every 10 km it is recommended to clean the candles, and change every 000 km. The maximum allowable clearance is 30 mm.
In this case, the power of the spark increases, but it is not enough for full ignition. If you have a carburetor, the candles will immediately flood, and the next start of the power unit is possible only after they are dried. A small gap is observed only in new candles, and it should be at least 0.4 mm, otherwise adjustment is required. The injector is less whimsical to gaps, since here the coils have a power several times higher than the carburetor ones, which means that the spark charge with a small gap will sag slightly.
Do I need to set a clearance
In case the distance between the electrodes differs from the factory values, independent adjustment is required. On the example of NGK candles, we find out what clearance is installed on the BCPR6ES-11 model. The last two digits indicate that the clearance is 1.1 mm. Not allowed discrepancy in a distance of even 0.1 mm. The instructions for use of your car should have a column indicating
what should be on a particular motor. If a gap of 0.8 mm is required, and BCPR6ES-11 plugs are installed, then the probability of stable operation of the internal combustion engine tends to zero.
Which candlelight clearance is better
Select the gap depending on the type of engine. It is enough to separate three classifications:
- injection (minimum clearance due to a powerful spark 0.5-0.6 mm)
- carburetor with contact ignition (gap 1.1-1.3 mm due to low voltage (up to 20 kilovolts))
- carburetor with non-contact ignition (0.7-0.8mm is enough).
How to check and set the gap
If your car is under warranty, then an official car service during scheduled maintenance checks the clearance between the candles. For independent operation, a probe for measuring gaps is required. The probe consists of a series of plates with a thickness of 0.1 to 1.5 mm. For verification, it is necessary to clarify the nominal distance between the electrodes, and if it differs upwards, then insert a plate of the required thickness, press on the central electrode and press it so that the probe comes out tight. If there is insufficient clearance, select the probe of the required thickness, push the electrode up with a screwdriver and bring it to the desired value.
The accuracy of modern probes is 97%, which is quite enough for complete adjustment. It is recommended that the candles be checked every 10 km on carburetor cars, since the likelihood of rapid wear increases due to the unstable operation of the ignition system and the carburetor. In other cases, THEN candles are produced every 000 km.
Questions and answers:
What should be the gap on the spark plugs on injection engines? It depends on the design features of the ignition system and the fuel supply system. The main parameter for injectors is from one to 1.3 millimeters.
How much gap should a spark plug have? It depends on the type of ignition and the fuel system. For carburetor engines, this parameter should be between 0.5 and 0.6 millimeters.
What is the gap on spark plugs with electronic ignition? The normal gap in spark plugs, which are used in engines with electronic ignition, is considered to be a parameter from 0.7 to 0.8 millimeters.