Spark plugs designed to ignite a fuel-air mixture in car engine, have several types of classification. First of all, this is a division by design, then there are differences in the materials of manufacture and in the thermal parameters of the candles.
Candle design
By their design, candles can be:
- two-electrode;
- multi-electrode.
How are spark plugs with two electrodes different? from those that have more of them? A classic two-electrode plug has one electrode protruding as a central one and one side, while in a multi-electrode structure, which also includes one central electrode, there will already be several side ones. The more electrodes, the more reliable the candle should work and the longer it can last. Although, of course, this version of the candles will be more expensive.
Candle materials
According to the materials from which the electrodes are made, candles are:
- platinum;
- iridium;
- classic.
In platinum spark plugs, the electrodes (both center and side) are made of platinum, which is highly resistant to temperature and corrosion. The platinum electrode practically does not fade, although it is, of course, not cheap. Such a candle lasts much longer than the "classic" one, the electrodes of which are made of copper.
However, standard spark plugs can also work for quite a long time if their copper electrodes are covered with rare metals, for example, yttrium. Moreover, their cost will be less than that of platinum ones.
Thermal parameters
Another parameter by which you can divide car candles - their heat number, which determines the thermal parameters. How spark plugs differ with different glow numbers? Those with a higher parameter work better at high temperatures, heat up less and are called "cold", the rest - "hot". "Hot" candles are quite reliable under light load, so they are used at relatively short travel distances. For long trips, during which the temperature of the candle can rise significantly, it would be more expedient to use the "cold" option.
However, at present, the range of glow numbers on different candles is not too large, and the difference between "hot" and "cold" candles is small. This is due to the almost identical fuel combustion processes in modern engines at any distance traveled by the car.
Spark plugs are a special device, the main purpose of which is to ignite the fuel-air mixture. These spark plugs are used in gasoline engines and differ in their performance characteristics... In this article, we will tell you about what cold spark plugs are. Let's take a closer look at how to tell the difference between hot and cold spark plugs.
Why choose the right spark plugs?
Many car owners, when operating their car, do not pay due attention to the issues of the correct choice and quality of the spark plugs used. But the indicators of engine power, its throttle response and fuel efficiency depend on this. That is why it is necessary to use high-quality candles, regularly carry out their maintenance and, if necessary, replace them.
The number of electrodes at the candle
Single and multi electrode hot and cold spark plugs are available today. Each of these varieties has certain advantages. Today, single electrode spark plugs are used primarily with older engines due to their short lifespan and instability.
Modern high-power high-power motors use multi-electrode plugs, which can have up to four side electrodes. They are characterized by durability and stability in operation. We note a significant reduction in exhaust toxicity and a reduction in fuel consumption when using such multi-electronic spark plugs. Their only drawback is their high price, which leads to a significant increase in the cost of servicing and repairing a car, especially when it is necessary to replace them with a set on a six or eight-cylinder engine.
Center electrode material
When choosing spark plugs, you must first of all pay attention to the material from which the center electrode is made. In inexpensive spare parts, iron, nickel, copper or zinc can be used for its manufacture. If you flood the spark plugs on a cold one, then thick iron electrodes may be the cause. But in high-level spark plugs, the electrode can be made of the noble metal of platinum, iridium and silver. The use of such metals makes it possible to carry out ultra-thin electrodes, which in turn gives a spark with a high power and prevents candles from flooding.
Of the advantages of candles with an electrode made of precious metals, we can note their excellent durability. So, for example, simple nickel plugs usually last 30,000 kilometers, and models with a platinum center electrode have a guaranteed service life of 100,000 kilometers.
Heat number, cold and warm candles
The heat number indicates the pressure in the cylinders at which the fuel mixture spontaneously ignites from a glowing plug. The appearance of such a glow ignition negatively affects the operation of the engine, leading to a loss of power and an increase in fuel consumption. Such spontaneous ignition of the fuel-air mixture leads to an increased load on piston group, which in turn reduces the engine life. Many car owners are wondering if spark plugs are cold and hot. This concept directly depends on the glow number.
It is the glow number that determines the thermal modes of operation of the candle. Accordingly, the higher this indicator, the more difficult conditions a particular spark plug is capable of operating. That is why it is necessary to consider this characteristic and compare with the performance of a particular engine internal combustion... It is customary to subdivide cold and hot spark plugs, the difference between which is in the glow number. As you can tell from the name, cold candles slowly heat up, and subsequently dissipate the resulting heat quickly. On the contrary, hot varieties of spark plugs heat up quickly, but at the same time such devices themselves slowly dissipate heat.
Hot plugs are recommended for engines that run at standard rpm. crankshaft... In such power units, the candles are not subjected to serious temperature loads, which allows for trouble-free ignition and the absence of spontaneous ignition of the mixture. Self-cleaning hot plugs are popular, in which such cleaning is performed at relatively low temperatures, which improves the flammability of the fuel mixture.
But cold spark plugs are characterized by increased resistance to temperature loads and are recommended for use in turbocharged and forced power units. Self-cleaning of such spark plugs occurs at high temperatures, therefore, it is not recommended to install them in conventional atmospheric non-boosted engines. In atmospheric engines, the temperature regime will prevent cold spark plugs from self-cleaning, which will lead to ignition problems. Most manufacturers recommend using these types of cold plugs with premium cars and sports cars with forced and turbocharged engines that operate at high temperature loads.
How to choose the right cold and hot candles
Choosing hot and cold candles is easy. It is necessary to pay attention to the candlestick index, and based on this, a choice should be made. For hot ones, this index ranges from 11 to 14, and the marking of cold spark plugs - from 20 and above. You can also pick up candles based on the recommendations of the car manufacturer. In the documentation for the car, you can find all the necessary information on factory spare parts, as well as recommendations for their selection when replacing. Also, in the car manual, you can find suitable brands of candles that are recommended for a particular car. All this will significantly simplify the choice, and the car owner can guarantee the hassle-free operation of his car.
Conclusion
When operating a car, you will invariably face the need to replace spark plugs. When choosing such spare parts, it is necessary first of all to take into account the indicators of the heating number. Hot and cold spark plugs are popular, the differences between which are only in the indicator of the glow number. It is depending on this characteristic that it is customary to distinguish between cold and hot plugs, which are intended for atmospheric and forced engines. For sporty high-powered engines, it is recommended to use cold spark plugs to ensure maximum power. power unit and no ignition problems. But for economical subcompact and atmospheric engines hot plugs are recommended, which have an affordable cost and are durable in operation. In this article, we discussed how cold spark plugs differ from hot ones. We hope that after reading this article, you will not have any difficulties with the choice.
The spark plug is the main part of an internal combustion engine and has two main functions:
- Ignition of the air-fuel mixture
- Removing heat from the combustion chamber
The main task for spark plugs is to ignite the air / fuel mixture. A spark plug is an electrode that transmits electrical energy from the ignition system to the combustion chamber in the form of a spark. The ignition system must generate enough voltage to generate a spark in the spark plug gap.
The spark plug tip temperature must be kept low enough to prevent early ignition and, at the same time, high enough to prevent the formation of carbon deposits. This property of the candle is called the heat characteristic and is determined by the selection of the heat range of the candle.
It is important to remember that spark plugs do not generate heat, they only dissipate heat. The spark plug functions as a heat exchanger, transferring excess heat energy from the combustion chamber and transferring it to the engine cooling system. Heat range is characterized as the ability of a candle to dissipate (transfer) heat.
The amount of heat transfer is determined by the following factors:
- Long working tip insulator
- The volume of the gas cavity around the insulator of the working tip of the candle
- Material and construction of center electrode and ceramic insulator
The heat range of the spark plugs is independent of the actual voltage transmitted through the spark plug. Rather, the heat range is the value of the candle's ability to remove heat from the combustion chamber. The magnitude of the thermal range is determined by several factors: the length of the ceramic central insulator of the working tip of the candle and its ability to absorb and transfer heat from the combustion process, the material of the insulator and the central electrode.
Heat output and heat flux through candles ignition NGK
Hot type
Cold type
The length of the insulator of the working tip of the plug is the distance between the tip of the insulator from the side of the spark gap and the point of contact of the insulator with the metal body of the plug. Since the tip of the insulator is the hottest part of the plug, its temperature is the primary cause of early ignition and carbon deposits. The spark plug tip temperature should be between 500 ° C and 850 ° C, whether used in a lawn mower, boat or racing car engine. |
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If the tip temperature is below 500 ° C, the surface of the insulator surrounding the center electrode will be insufficient to burn off carbon and other deposits. Sediment build-up can cause plug fouling, leading to misfiring. If the tip temperature is higher than 850 ° C, the spark plug will overheat, which can damage the ceramic shell of the center electrode and melt the electrodes. This can lead to early ignition / knocking and serious engine damage. For the same type of spark plug, a 1 unit change in the heat range results in a 70 ° C to 100 ° C change in temperature in the combustion chamber, while the temperature of the tip of the spark plug with a protruding ground electrode changes by 10 ° C-20 ° C. ...
Insulator tip temperature and appearance spark plug
The appearance of the spark plug also depends on the temperature of the tip of the spark plug. There are three main criteria for diagnosing spark plugs: normal, dirty, and overheated. The interface between the areas of contamination and optimal functioning is about 500 ° C and is called the self-cleaning temperature of the plug. At this temperature, the accumulated carbon and other deposits are burned off. It should be borne in mind that the length of the spark plug insulator is the determining factor in the spark plug heat range. The longer it is, the less heat is absorbed and, in the future, the heat must be transferred to the cooling water in the channels of the cylinder head. This means that the plug has a higher internal temperature and is a hot plug. The hot plug maintains a high internal operating temperature, allowing the combustion of oil and carbon deposits, regardless of the intensity or quality of the spark. Conversely, a cold-type spark plug has a shorter insulator length and absorbs more heat from the combustion chamber. The heat travels a shorter distance, allowing the candle to operate at a lower internal temperature. The cold range is required for heavy duty operation or work on high revs for an extended period of time. Cold plugs dissipate heat more quickly and thus reduce the chances of early ignition / detonation and melting or damage to the tip of the plug. (Engine temperature can affect the operating temperature of the plug, but not the heat range of the plug.) |
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Below is a list of some of the possible external factors affecting the working temperature of the plug. The following symptoms or conditions may affect the actual candle temperature. The plug cannot create these conditions, but must be able to withstand thermal loads, otherwise performance will suffer and the engine may fail.
Air-fuel ratio / quality has a significant impact on engine performance and spark plug operating temperature.
- The rich air / fuel mixture causes the spark plug tip temperature to drop, causing carbon deposits and poor performance.
- A poor air / fuel mixture causes the temperature in the combustion chamber and spark plug tip to rise, resulting in early ignition, detonation and the possibility of serious damage spark plugs and engine.
- It is important to check the condition of the spark plugs repeatedly during operation to achieve the optimum air / fuel ratio.
High compression / boost raise the temperature in the combustion chamber and the temperature of the spark plug tip.
- Compression can increase with the following modifications:
- reducing the volume of the combustion chamber, that is, the use of domed pistons, modified cylinder heads, etc.
- additional boost (Nitrous, Turbocharging or Supercharging)
- camshaft modification
- With increasing compression, you should: use lower plugs temperature range; use high-octane fuel; it is necessary to carefully and carefully select the ignition timing and the ratio of the air-fuel mixture. Failure to select a cold spark plug can result in spark plug / engine damage.
Displacement of the ignition moment forward
- Moving the ignition timing forward by 10 ° will heat the spark plug tip by about 70 ° -100 ° C Engine RPM and load.
- The increase in spark plug tip temperature is proportional to the increase in engine speed and engine load. When operating at high speeds or under heavy load, plugs in a colder heat range should be installed.
Ambient temperature
- With a decrease in the ambient air temperature, the density / volume of air increases, as a result, a depletion of the air-fuel mixture occurs.
- This increases the temperature / pressure in the cylinder and causes the spark plug tip temperature to rise. Thus, the fuel supply should be increased.
- As the temperature rises, the density and volume of the intake air decreases, therefore the fuel supply should be reduced.
Humidity
- As the humidity rises, the intake air volume decreases.
- As a result, compression and combustion temperature decrease, causing a decrease in plug temperature and available power.
- Lean the air-fuel mixture depending on the ambient temperature.
Barometric Pressure / Altitude
- Also affects the temperature of the working tip of the candle.
- Compression decreases as altitude rises. Due to the drop in combustion temperature, the temperature of the working tip of the spark plug decreases.
- Many mechanics try to change the heat range of the candles while doing this.
- The most realistic option is to adjust the jets or air / fuel ratio in order to increase the air supply to the engine.
OPTIONS FOR ABNORMAL COMBUSTION PROCESS
Early ignition timing
- Defined as: ignition of the air-fuel mixture before the pre-set level.
- Caused by hot spots in the combustion chamber, this may be due to: early ignition timing, spark plug overheating, low octane fuel, lean air / fuel mixture, excessive compression, insufficient engine cooling.
- Increasing the octane rating of the fuel, using a colder heat range plug, enriching the air / fuel mixture, or reducing compression may help.
- It may also be necessary to shift the ignition timing to the lag side and check the cooling system.
- An early ignition timing usually results in detonation. Early ignition and knock are two separate cases.
Detonation
- Spark plugs' worst enemy! (along with carbon deposits).
- May cause damage to insulators or grounding electrodes.
- In most cases, an early ignition moment leads to detonation.
- The spark plug tip temperature during combustion can exceed 1650 ° C (racing engines).
- Most often caused by overheated areas of the combustion chamber.
- Overheated areas will cause the air-fuel mixture to ignite early. When the piston is pushed up by the action of the connecting rod, premature ignition of the mixture will cause a force in the opposite direction. If the piston cannot move upward (due to premature ignition) and cannot move downward (due to the upward movement of the connecting rod), it will wobble from side to side. As a result, the shockwave will translate into an audible dull sound. This phenomenon is called detonation.
- The destructive effect for the engine is more critical from the occurrence of detonation than from overheating.
- Spark plugs are damaged from both elevated temperatures and concomitant shockwaves or concussion. st>
- It is believed that a spark plug gives a misfire when, at the right moment of the piston stroke, a spark discharge insufficient for complete ignition of the air-fuel mixture is supplied to the combustion chamber (several degrees before top dead center).
- A spark plug can generate a weak spark (or not generate a spark at all) for various reasons: a damaged ignition coil, too high compression coupled with an incorrect spark plug gap, dry or wet deposits on the spark plugs, lost ignition timing, etc.
- Minor misfires can cause a loss of power for obvious reasons (no power generated, intermittent fuel supply).
- Frequent misfiring will cause increased consumption fuel, poor performance and can damage the engine. st>
- Occurs when the spark plug tip is not hot enough to burn carbon, fuel, oil, and other deposits.
- Will cause the electrodes to short to ground, so that the spark does not jump through the spark plug gap, respectively, misfires will occur.
- Wet candles must be replaced as no spark occurs.
- Occasionally, dry plugs can be cleaned by increasing the engine operating temperature.
- Before replacing slag spark plugs, make sure that the cause of the contamination has been eliminated. st>
Interruptions / misfires
Nagar
SPARK PLUG DIAGNOSTIC PROCEDURE
With a competent diagnosis of the spark plug, it can be an assistant in various engine settings. By analyzing the color of the spark plug insulator, an experienced mechanic can obtain a wealth of information about the operating conditions of an engine.
In general, a light tan / gray color of the plug indicates that the engine is operating normally at the optimum temperature. Dark color, such as black wet or dry deposits, can indicate an overly rich mixture, a too cold heat range for the plug, possible vacuum drop, low compression, late ignition timing, or a spark plug gap that is too large.
The presence of wet deposits can be caused by damage to the cylinder head gasket, wear oil scraper ring, or the occurrence of problems in the timing mechanism, or the engine running on excessive rich mixture- depending on the composition of wet deposits on the working tip of the candle. Traces of carbon build-up or overheating should be detected as soon as possible to prevent deterioration in ride performance and engine damage.
DRY AND WET DEPOSITS
Although there are many different options, if the resistance between the center and ground electrodes is greater than 10 ohms, the engine can start normally. If the insulator resistance drops to 0 ohms, the ignition end of the spark plug is contaminated with either dry soot or wet oil deposits.
Reasons for the formation of soot deposits: incorrect carburetor adjustments; too rich fuel-air mixture; heavy pollution air filter; weak spark; malfunction / jamming of the air damper; the problem most often occurs when using the motor to travel short distances; the spark plugs are at too low operating temperature; spark plug heat range index too low. Result: Fixes: adjust the settings of the carburetor and choke; check the condition of the air filter. If only one or two of the kit plugs are dirty, check for sticky valves or faulty ignition leads. After correcting the cause of the malfunction, the spark plugs must be serviced and reinstalled. |
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Reasons for the formation of oil deposits: high oil content in the combustion chamber. Increased oil level in the engine crankcase; wear piston rings, cylinder liners or valve guides. It can occur during the break-in period of a new engine or an engine after overhaul (such dirty plugs can be serviced and installed again). Result: misfiring, difficulty starting the engine. Fixes: holding overhaul engine, adjust the fuel-oil ratio (2-stroke engines), replace the spark plugs with new ones. |
LEAD DEPOSIT AND OVERHEATING
When the spark plug overheats, the deposits that accumulate on the working tip of the insulator melt and give it a glazed or glossy brownish yellow appearance.
Causes: a sharp increase in temperature in the combustion chamber caused by a sharp acceleration under heavy load leads to the formation of varnish deposits. Also, the use of fuels with lead-containing additives leads to the formation of varnish deposits. Result: under heavy load, varnish deposits become electrically conductive and lead to misfiring. They cannot be detected by measuring the resistance between the center and ground electrodes at room temperature. Fixes: replace spark plugs with new ones. If these phenomena recur, it is recommended to use candles with a colder range and service them more often. |
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The insulator is cloudy white or gray and looks puffy. The electrodes are eroded and no deposits are observed. Causes: using spark plugs with too high a heat range; excessive ignition timing; malfunction of the engine cooling system; depletion of the fuel-air mixture; Intake manifold leakage or stuck valves.Fixes: check the correctness of: used heat range of the spark plug, setting the ignition timing, adjusting the carburetor; check the tightness of the intake manifold and the condition of the valves. Replace spark plugs. |
ASH DEPOSITS
Copious white or yellow powdery deposits on insulator and grounding electrode. It is recommended to check the serviceability of the engine, in some cases it is recommended to replace the spark plugs with new ones. It may be necessary to change the type of machine oil used.
CHIP, CRUSHING, INSULATOR DESTRUCTION
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Causes: insulator failure is usually caused by thermal expansion and thermal shock due to sudden heating or cooling; mechanical damage caused by dropping the spark plug, or applying excessive force to the center electrode when setting the gap; in exceptional cases, the formation of deposits between the center electrode and the insulator, as well as corrosion of the center electrode, can lead to the destruction of the insulator (this often happens when the engine has been used for too long). Result: misfiring, the spark jumps in the gap inaccessible for ignition of a fresh portion of the fuel-air mixture supplied to the combustion chamber. Fixes: |
LEAD erosion Typical lead erosion causes a thinning of the ground electrode and the tip of the center electrode looks split. Causes: lead erosion is caused by the presence of lead impurities in the fuel, which at high temperatures enter into a chemical reaction with the electrode material (nickel alloy); the structure of the nickel alloy is destroyed due to the penetration and separation of the grain structure of the nickel alloy by lead compounds. Result: misfiring, difficult starting. Fixes: replacing the spark plug with a new one. |
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ELECTRODE MELTING
Running the engine at an excessively high temperature in the combustion chamber results in excessive early ignition and melting of the electrodes. The melting point of nickel alloy is 1,200 ~ 1,300 ° C. The central electrode melts first, then the ground electrode. Most often, the surface of the electrode is glossy and uneven, the insulator is white, has a porous and soft structure, but can be dirty if there are misfires in the ignition. The electrodes can be partially melted with the presence of molten foreign inclusions on them (far right).
Result: misfiring; loss of power (engine damage).
The spark plug is essential element an engine ignition system that directly ignites the air-fuel mixture in the combustion chamber. V modern cars candles of various designs and operational parameters are used, but they all have a similar principle of operation.
Device and role in the car
Spark plug designThe basic design of a candle includes the following elements:
- Metal body with threaded on the outside for attaching the spark plug to the cylinder head. It also carries out the function of removing excess heat and serves as a conductor from the "ground" to the side electrode.
- Insulator. It usually has a ribbed surface, which lengthens the actual path of surface currents and prevents surface flashover.
- Center and side electrodes, between which a spark is generated that ignites the air-fuel mixture. The side electrode is made of steel alloyed with nickel and manganese. The central one is made of precious metals, which ensures the possibility of self-cleaning of the electrode.
- The terminal for attaching the spark plug to high-voltage wires ignition systems. The connection can be threaded or snap-in contact.
A resistor may also be provided in an automotive spark plug device. Its main task is to suppress the interference created by the ignition system. The resistance can vary from 2 kOhm to 10 kOhm.
Plugs used in internal combustion engines are also called spark plugs. They form a spark at each compression stroke (or compression and exhaust when applied), igniting the air-fuel mixture at a certain point, throughout the entire time the engine is running. As a rule, there is one plug for each cylinder of the engine (with the exception of engines of the Twinspark type), which is screwed by means of a thread into special holes in the cylinder head housing. In this case, the working part is located in the combustion chamber of the engine, and its contact outlet is outside.
Improperly tightened spark plugs can result in precarious work motor. Insufficient tightening will reduce the compression in the combustion chamber. If tightened too tightly, mechanical deformation can occur.
Principle of operation and characteristics
Sparking on the electrodes The main task of a candle is to form a spark and maintain it for the required amount of time. To do this, low voltage from the car battery is converted into high (up to 40,000 V) in the ignition coil, and then fed to the spark plug electrodes, between which a gap is made. "Plus" from the coil comes to the central electrode, "minus" - on the side of the engine.
At the moment of the formation of voltage on the electrodes ("plus" from the coil on the central and "minus" on the side from the motor), sufficient to overcome (breakdown) the resistance of the medium in the gap, a spark appears between them.
Spark gap value
Spark gap is the main parameter of spark plugs. It determines the minimum distance between the electrodes, which ensures the formation of a spark of sufficient size and the possibility of breakdown of the corresponding layer of the medium (fuel-air mixture under pressure).
Spark gap The size of the gap must be within the limits specified by the manufacturer. If the gap is too large, the energy of the spark discharge may not be enough to maintain the required burning time of the candle and the mixture may not ignite. On the other hand, too small a gap will lead to burnout of the electrodes and increased wear of the spark plugs.
The size of the spark gap differs depending on the operating mode of the engine and its type and manufacturer. The lower threshold of the spark gap can be about 0.4 mm, and the upper one can be up to 2 mm.
To check the size of the spark gap, a special tool is used - a dipstick, which can be round or flat. The second type is easier to use, but gives an error, since it does not take into account the wear of the electrode surface. Adjustment of the gap to the required size is performed manually by bending the side electrode.
What is the incandescence number
The location of the spark plug in the engine An equally important parameter is the incandescence number. It determines the thermal properties of the structure and demonstrates at what pressure in the combustion chamber uncontrolled self-ignition of the air-fuel mixture (glow ignition) can occur. In simple words, the higher the glow rate, the less the spark plug will heat up during engine operation.
Constructions with different heating values are used according to the type of motor, mode and conditions of its operation. So, in the summer and at increased loads, it is optimal to use structures with a high heat rating, and in winter or during quiet driving in city limits - with a lower one.
Low glow number plugs are installed in low pressure engines operating on low octane fuel. Conversely, designs with a high heat rating are used in engines with increased compression and high temperature loading of the combustion chamber.
Types and marking
Spark plug markings In order not to be mistaken when choosing a model, you should pay attention to the marking of the spark plugs purchased. Each manufacturer has its own.
The first parameter is, as a rule, the diameter of the threads and the shape of the bearing surface, demonstrating the possibility of actually installing the plug on a particular engine.
The R (P) symbol often indicates the presence of a resistor in the design. Further, the glow number, the size of the spark gap and the material from which the electrodes are made are indicated.
According to the number of electrodes, spark plugs are divided into two types:
- Single electrode.
- Multi-electrode - they have multiple side electrodes. The spark arises with the one with the least resistance.
Depending on the magnitude of the glow number, the candles are divided into:
- hot with a heat rating from 11 to 14;
- medium - from 17 to 19;
- cold - from 20 and above;
- unified - from 11 to 20.
Spark plugs with different number of electrodes According to the type of material of the central electrode, spark plugs are distinguished:
- iridium;
- yttrium;
- tungsten;
- platinum;
- palladium.
Iridium automotive spark plugs are considered to be the most durable and wear-resistant. They are used in high-power engines, but when installed on conventional motors, they do not create significant improvements.
Service life and common faults
In practice, you can determine when to change spark plugs by taking into account several aspects:
- The manufacturer's stated service life for a particular brand of spark plugs. For example, the replacement frequency for standard models is up to 50 thousand kilometers, for platinum models this figure is 90 thousand kilometers, and the most expensive iridium spark plugs serve up to 160 thousand kilometers.
- Operating conditions. When using low-quality fuel, the actual service life will be less than the manufacturer's declared one by 20%. At the same time, iridium is especially sensitive among spark plugs.
- Condition of the electrodes. They can burn out during long-term operation or as a result of a violation of the engine operating modes. Cleaning of electrodes can be done mechanically or spontaneously (when high temperatures are reached). It should be noted that iridium and platinum spark plugs cannot be mechanically cleaned.
- Insulator state. It can be dirty or destroyed.
Correct start and engine power, fuel consumption and CO content in exhaust gases depend on the performance of this, at first glance, simple element, and therefore the answer to the question of why change the spark plugs in a timely manner is quite obvious.
Starting the engine, its uninterrupted work, efficiency and turnover can be associated not only with the normal functioning of all systems. An important role in this is played by spark plugs, on which the ignition of the fuel-air mixture depends. Therefore, it is worth knowing about the characteristics of these elements, the selection rules and the brands offered on the market.
The importance of making the right choice
If you correctly approach the choice of a candle, then you can avoid the following problems:
- regular spending on the purchase of new candles due to the rapid failure of recently purchased ones;
- high efficiency of spark supply for a long time;
- breakage of the socket for the candle;
- increased fuel consumption.
Therefore, it is worth considering many parameters when purchasing a set of candles.
Spark plug types
Spark plugs are classified in terms of the number of electrodes per type:
- Two-electrode - there are two electrodes (central and side);
- Multi-electrode - contain several side electrodes.
Multi-electrode designs allow for increased motor stability. When additional side electrodes are present, sparking is bound to happen. Indeed, in case of failure of one element, the other will work. The presence of multiple electrodes increases the service life.
On sale you can find candles with auxiliary electrodes located on the insulator. They create several discharges at the same time. But the price of such elements is higher compared to the classical design.
By the type of material, candles are divided into:
- Classic - alloy steel, supplemented with manganese, chromium and nickel, is used as the basis for manufacturing;
- Platinum - there is a sprayed layer of platinum;
- Iridium - covered with an iridium film on top.
The classic (standard) version appeared a long time ago. Nickel electrode ensures long plug life. The core made of copper has good heat dissipation properties, which prevents heat stress. The standard variety is considered an inexpensive option due to the use of cheap materials.
Platinum spark plugs are an innovation in the automotive industry. They have a long service life due to the use of a noble metal - platinum. In addition, this additive contributes to the achievement of constant power under a variety of operating conditions. The electrode of this type has a thinner shape compared to a standard candle.
Iridium spark plugs have been designed to reduce ignition voltage and improve flame distribution during combustion. The iridium metal is very hard and does not corrode. Thanks to these properties, manufacturers have been able to produce a thin electrode shaft that is very durable. Such candles can be used for a long time. But the price of products increases significantly.
Spark plug characteristics
Having decided on the type of candle, you should also familiarize yourself with the additional characteristics:
- The glow number is a parameter indicating the pressure in the cylinder at which glow ignition will appear. The mixture ignites at high temperatures. This temperature should come from a spark. If the temperature comes from a heated electrode, then glow ignition occurs. The heat number indicates the temperature mode of the candle itself. In the case of a large value of this indicator, less heating of the candle itself occurs. A low glow rate increases the heating ability of the plug, which eventually leads to burnout of pistons and gaskets. It is forbidden to use candles with a low incandescence value, the value of which is lower than that recommended in the car manual.
- Thermal index is a parameter that means dependence temperature regime candles in working order from the operating mode of the motor. The tip of the insulator should be heated within 500-850 ° C. At temperatures below the minimum point of the specified range, the surface of the insulator will not be able to self-clean from burnt residues. Subsequently, they will create an obstacle that will affect the misfire. At temperatures above 850 ° C, the candle will not be able to remove heat and overheat. As a result, the ceramic shell will crack and the electrodes will melt. In terms of thermal parameters, candles are “hot” (it heats up to a greater extent) and “cold” (it removes heat well). "Hot" elements are required in situations where a high temperature condition of the plug is required at a high engine load. "Cold" candles are used in order to achieve a lower temperature regime at the time of peak engine loads, but they quickly become covered with carbon deposits. Manufacturers mark the candles with a different digital code corresponding to the heat value coefficient. For different firms, a large coefficient may indicate a "hot" or "cold" candle.
- The spark gap is the section between the center and side electrodes. Increased distance affects misfire. As the distance decreases, the energy of the spark cannot “play out”. The factory gap does not need to be changed as the adjustment will result in reduced efficiency or interruptions in operation.
- Size - determined by the diameter and length of the thread. The thread diameter is 10.12, 14, 18 mm. But modern motors are manufactured with smaller spark plug openings to save cylinder space for the fuel injector and additional valves. And also new engine models are designed for increased thread lengths. After all, now aluminum candle heads are being made, and not durable cast iron. Due to the increased wall thickness of the head, the probability of thread rolling is reduced to zero.
An important characteristic of spark plugs is their service life. If we take into account all of the above parameters, then the period of operation depends on them to some extent. If the candle is selected correctly, it will serve the prescribed 20-30 thousand km. But provided that there are no problems in work fuel system or engine.
Manufacturers and their serial releases
Today, the following manufacturers are popular:
| Company / Country | Series | Features of the series | General qualities |
| Bosh / Germany | Super | Copper center electrode is chromium-nickel coated | Wear resistance, spark stability, improved fuel combustion, resistor to reduce interference, excellent start-up in severe frosts (platinum version) |
| Super plus | The center electrode is made of yttrium-nickel alloy and the side electrode has a pointed shape | ||
| Super plus 4 | The production is based on the same components as the Super plus, but there are 4 side electrodes | ||
| Platinum | The center electrode is made with platinum alloy and the insulator is made of ceramic | ||
| NGK / Japan | No separate episodes | The insulator is made of ceramic | High performance under peak loads and high temperatures, widely used as standard elements by many car manufacturers |
| Denso / Japan | Standard | Electrodes are made of copper, nickel, chromium, there is a noise suppression resistor | High efficiency of fuel combustion, increased performance indicators, wear resistance |
| Platinum | There is a thin platinum electrode | ||
| Iridium | Center electrode made of iridium alloy | ||
| Twin Tip | The electrodes are made of nickel using a special technology, which is designed for increased wear resistance | ||
| Brisk / Czech Republic | Classic | For carburetor type | The series are designed for a specific injection system, used fuel |
| Super | For injection engines any production | ||
| Forte | The center electrode is much thicker | ||
| Extra | Multiple side electrode components | ||
| Silver | Used on vehicles running on gas | ||
| Platin | Platinum center electrode | ||
| Premium | Produced using a special technology that ensures increased power sparks | ||
| A-line yttrium | Yttrium center electrode, candles are designed for use in foreign cars | ||
| Champion / USA | Copper Core OE | Two-electrode version made with copper and zinc (frame) | Acceptable service life, improved heat transfer |
| Double Copper OE | The design has a copper center solid-drawn electrode | ||
| OE | Multi-electrode option | ||
| Platinum OE | There are platinum refills on the center electrode |
Things to Consider When Selecting Spark Plugs
There are no universal candles. Different models car involve the use of special types. Therefore, it is necessary to focus on such nuances:
- Read the vehicle manual for the required specifications.
- View information in manufacturers' catalogs on the use of spark plugs in certain engine designs, as well as learn about product labeling.
- Take into account the fuel used.
- You should not rely on the price of products, since expensive platinum or iridium options are distinguished by a long service life.
- A small candle will not screw into the socket, and a large one can damage the internal parts of the unit.
- If a strong burnout of the electrode, "ulcerative surface" of the insulator is detected, the next time elements with an increased heat rating should be selected (first, it is necessary to exclude the valve hanging, overheating, insufficient cooling of the motor).
- If the driving style involves constant overglowing, replacing the spark plugs will not help get rid of the yellow plaque. It is required to exclude abrupt start and "kick-downs".
The use of candles involves them correct installation... It is not necessary to re-install previously used spark plugs. The replacement of individual elements is also excluded.
In the video you can learn more about the types, parameters, marking of spark plugs. Violations in their work are also described.
After reading the operating instructions for your car, and taking into account all the shortcomings in the operation of the motor, you can buy the correct spark plugs. As a result, the engine will run smoothly and deliver excellent power. And fuel costs will only be associated with higher prices.
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