Everything you ever wanted to know about spark plugs, and maybe more...
Everything you ever wanted to know about spark plugs, and maybe more...
Thought this might be a good reference to have on the .org...
I personally haven't found any single thread on the forums that goes through a comprehensive explanation relating to spark plugs. I've been sifting through a ton of scattered information and decided to make a thread to organize it all. NGK plugs are focused on, should be helpful since the consensus appears to be NGK for our Maximas.
Anatomy of a Spark Plug
How does a spark plug work?
The spark plug forces electricity to arc across a gap, just like a bolt of lightning. This spark ignites gas/air mixture in the cylinder to create a controlled explosion/combustion. This combustion force pushes the cylinder downwards to power the engine. The electricity must be at a very high voltage in order to travel across the gap and create a good spark. Voltage at the spark plug can be anywhere from 40,000 to 100,000 volts.
The spark plug must have an insulated passageway for this high voltage to travel down to the electrode, where it can jump the gap and, from there, be conducted into the engine block and grounded. The plug also has to withstand the extreme heat and pressure inside the cylinder, and must be designed so that deposits from fuel additives do not build up on the plug.
Spark plugs use a ceramic insert to isolate the high voltage at the electrode, ensuring that the spark happens at the tip of the electrode and not anywhere else on the plug; this insert does double-duty by helping to burn off deposits. Ceramic is a fairly poor heat conductor, so the material gets quite hot during operation. This heat helps to burn off deposits from the electrode.
Some cars require a hot plug. This type of plug is designed with a ceramic insert that has a smaller contact area with the metal part of the plug. This reduces the heat transfer from the ceramic, making it run hotter and thus burn away more deposits. Cold plugs are designed with more contact area, so they run cooler. Car manufacturers will designate the correct temperature plug for each car. Cars with high-performance engines naturally generate more heat, so they need colder plugs.
Types of Electrodes
Spark plugs with fine wire center electrodes operate better for two reasons. First, a smaller center electrode requires less voltage to jump the gap. This means fewer misfires, which will be seen in higher mileage and more horsepower. The second reason is smaller center electrodes reduce quenching. The smaller center electrodes have required exotic metals such as platinum or iridium so that they can still maintain (and sometimes surpass) the longevity of a traditional spark plug. NGK makes both platinum fine wire (1.1mm diameter center electrode) plugs and Iridium ultra-fine wire (0.7mm diameter center electrode), a traditional center electrode is typically 2.0 to 2.5mm.
V-Power spark plugs are a patented design by NGK. Ignitability is improved by the V-groove cut in the center electrode parallel to the ground electrode, this directs the spark to to the edge of the center electrode thus exposing it to more of the air/fuel mixture. Quenching is reduced in much the same manner, drawing the spark to the edge of the center and ground electrodes reduces the surface area available to quench the spark. See quenching for more info.
Traditional center electrode
Taper cut center electrode
Fine wire platinum
Ultra fine wire iridium
V-Power
Heat range
The term spark plug heat range refers to the speed with which the plug can transfer heat from the combustion chamber to the engine head. Whether the plug is to be installed in a boat, lawnmower or racecar, it has been found the optimum combustion chamber temperature for gasoline engines is between 500°C–850°C. When it is within that range it is cool enough to avoid pre-ignition and plug tip overheating (which can cause engine damage), while still hot enough to burn off combustion deposits which cause fouling.
The spark plug can help maintain the optimum combustion chamber temperature. The primary method used to do this is by altering the internal length of the core nose, in addition, the alloy compositions in the electrodes can be changed. This means you may not be able to visually tell a difference between heat ranges. When a spark plug is referred to as a “cold plug”, it is one that transfers heat rapidly from the firing tip into the engine head, which keeps the firing tip cooler. A “hot plug” has a much slower rate of heat transfer, which keeps the firing tip hotter.
An unaltered engine will run within the optimum operating range straight from the manufacturer, but if you make modifications such as a turbo, supercharger, increase compression, timing changes, use of alternate racing fuels, or sustained use of nitrous oxide, these can alter the plug tip temperature and may necessitate a colder plug. A rule of thumb is, one heat range colder per modification or one heat range colder for every 75–100hp you increase. In identical spark plug types, the difference from one full heat range to the next is the ability to remove 70°C to 100°C from the combustion chamber.
The heat range numbers used by spark plug manufacturers are not universal, by that we mean, a 10 heat range in Champion is not the same as a 10 heat range in NGK nor the same in Autolite. Some manufacturers numbering systems are opposite the other, for domestic manufacturers (Champion, Autolite, Splitfire), the higher the number, the hotter the plug.
For Japanese manufacturers (NGK, Denso), the higher the number, the colder the plug.
http://www.ngk.com/glossaryImages/721.jpg
Do not make spark plug changes at the same time as another engine modification such as injection, carburetion or timing changes as in the event of poor results, it can lead to misleading and inaccurate conclusions (an exception would be when the alternate plugs came as part of a single precalibrated upgrade kit). When making spark plug heat range changes, it is better to err on the side of too cold a plug. The worst thing that can happen from too cold a plug is a fouled spark plug, too hot a spark plug can cause severe engine damage
Common Types of Plug Failure
More Extensive List/Pics here (hint: zoom in)....http://img.photobucket.com/albums/v2...n22/img017.jpg
Fouling
Fouling occurs when the spark plugs' firing tip becomes coated with excessive fuel, oil, or combustion deposits so that it is unable to produce a spark. A plug can become fouled from continuous low speed driving, improper spark plug heat range (too cold), improper timing (over-retarded), too rich an air/fuel ratio or an oil leak into the combustion chamber. A variety of self-cleaning features are designed into most plugs to reduce fouling.
wet fouling image
dry fouling
Bridging
Bridging happens when deposits accumulate between the center electrode and the outer shell or base of the ground electrode. These deposits can form a "bridge" for an improper spark path from the center electrode to the outer shell. The accumulation of deposits on the firing end can be caused by oil leakage, fuel quality and the engine's operating duration. Depending on the application, there are a variety of self cleaning designs used by NGK to reduce bridging.
Pre-ignition
Ignition of the air/fuel mixture prior to its timed ignition by a spark from the spark plug is referred to as "pre-ignition". This can be caused by a hot spot in the combustion chamber, improper timing, too hot a spark plug, low octane fuel, too lean an air/fuel mixture, or engine overheating.
Flashover
Flashover is when the voltage sent to the spark plug does not fire between the center and ground electrodes within the combustion chamber. Instead, it shorts between the metal shell and the terminal nut on the plug exterior, causing the engine to misfire. This can occur when the air is highly ionized (such as on a stormy day), or when the insulator is dirty. Ribbed corrugations on the top portions of the insulator can reduce flashover.
Quenching
Quenching is when the heat generated by the spark is absorbed by the center or ground electrodes instead of igniting the air/fuel mixture. To understand quenching and how it is reduced it is first necessary to review the basic purpose of the spark plug is to ignite the air fuel mixture in the combustion chamber. To do this your vehicle ignition system generates tens of thousands of volts to jump the gap between the center and ground electrodes. However it is good to know that it is not the actual electricity that ignites the air fuel mixture, it is the heat energy generated by that electricity or spark. Therefore when you are creating the spark you want as much of the heat from that spark to be used to ignite the air fuel mixture and not have the heat from that spark be re-absorbed by the center and ground electrodes. Cut back ground electrodes, V-groove center electrodes, fine wire center and ground electrodes all resist quenching by reducing the surface area between the electrodes and the flame nucleus.
The NGK Lineup
Standard: Copper standard plugs offer heat-range tunability with OEM-Spec manufacturing quality and excellent product reliability standards.
V-Power: Like the standard plugs with a groove in the center electrode. Modern lean-burning, fuel efficient engines create a new set of requirements for spark plugs. NGK Spark Plugs answered the call for a spark plug with lower sparking voltage requirements by developing the V-Power, the only spark plug with a v-groove center electrode on the market today. Why is this important? The v-groove center electrode on a V-Power spark plug forces the spark to the outer edge of the ground electrode, placing it closer to the air/fuel mixture. What this does is allow the spark to more quickly ignite the mixture, providing more complete combustion. More complete combustion not only provides more power, it also means less harmful emissions. These emissions are not only damaging to the environment, they can reduce the life of expensive catalytic converters and oxygen sensors. V-Power Spark Plugs also require lower ignition firing voltage, resulting in quicker starts and easier cold weather starts throughout the life of the plugs. NGK V-Power Spark Plugs also are ideally suited for race cars and high performance street cars. Today's performance engines are high compression/high stress applications. Many are supercharged, turbo-charged or nitrous oxide fed. NGK's patented v-groove design allows the ignition system to easily spark in these dense air/fuel mixtures. The flame kernel will quickly grow and allow the engine to potentially make more power since it now is operating more efficiently. As an added bonus, the v-groove forcing the spark to the outer edge of the ground electrode helps reduce the "quenching" effect, reducing misfires caused by high cylinder pressures "blowing out" the spark.
G-Power Platinum: Another precious metal just became more affordable. The G-Power Platinum Spark Plug is designed to deliver the power, performance and quality at a very competitive price. (typically $3/ea) The G-Power Spark Plug features an extremely fine center electrode of platinum combined with a sharp pointed ground electrode designed for better igniting performance. When compared to conventional plugs, the result is a spark plug that delivers better starts, acceleration and greater fuel economy.
Platinum: The platinum material on the center and ground electrode is harder than copper and resists wear. Owners enjoy the extended miles between plug replacement. Seems to be the middle man between performance and plug life. Manufacturer recommends these NOT be used with nitrous.
Iridium IX: Features a 0.6 mm iridium center electrode tip, they offer improved ignitability without sacrificing durability. The tapered ground electrode increases flame kernel expansion, while the superior heat range design is can meet the demands of higher performance. Offer improved acceleration and high fuel efficiency and long life. However, I've read a number of user reviews that suggest these plugs wear out faster than platinums despite iridium being 7x harder than platinum. (Maybe due to thinner layer used secondary to increased cost of metal?)
Laser Iridium/ Laser Platinum Plugs: Laser welding process that provides a 360° seal so the electrode resists wear even in the worst conditions. Supposedly causes engines to run cleaner by using less fuel and more air, which in turn improves engine performance while lowering emissions.
Metal Properties Comparison Chart
Common Questions
Can I use Iridium plugs with nitrous injection or a blown alcohol motor?
Yes, and Yes.
We double checked with the tech’s on this one, they say, while they have been watching for problems, thus far, there has been no reports of any problems in using iridium plugs with a nitrous system.
There should not be any problems using Iridium with a blown alcohol motor
Should I gap my Iridium Plugs?
The manufacturers say NO.
This is because most people do not know how to properly gap a spark plug, and the center electrodes on the ultra-fine iridium can easily snap if mishandled. There is no warranty for snapped center electrodes. The manufacturers say an iridium spark plug will run so much better than a traditional plug, even if it is not gapped for that motor, that they would prefer you just leave it rather than risk snapping the center electrode.
How long will my Iridium spark plugs last?
A traditional iridium plug such as a ZFR6FIX-11 has an iridium center electrode, however the ground electrode is the traditional nickel construction. The ground electrode will wear out first. The manufacturers of Irdium plugs are saying 40,000 to 60,000 miles. But they have to temper their projections as driving conditions and motor modifications differ. Typically we have found you can expect 60,000 to 80,000 miles on anunaltered motor. (the wife’s mini-van has had Iridiums for 76,000 miles, I examined 2 of the plugs, they had some minor wear on the ground electrode, I put them back in and will likely change them in another 5,000 miles)
Some NGK Iridium racing plugs have iridium center and a platinum ground electrodes. If installed to a regular engine they would likely last longer than most people keep their car (barring any motor problems that can cause premature plug death). But, these usually come in heat ranges too cold for an unaltered motor and are usually used in racing applications where all bets are off.
For the traditional automotive market, the longest lasting plugs are the NGK "IFR" series. These have Iridium center and platinum tipped ground electrodes, however these are extremely limited in application as they only manufactured these in a couple of heat range configurations.
Can I use platinum plugs with nitrous injection?
No, it is not suggested to use platinum plugs with nitrous oxide injection.
There have been instances where the platinum tip has lost its bond to either the center or ground electrode when they were used in a motor with nitrous.
Thus far tech's say they have had no problems using Iridium plugs with nitrous.
Can old spark plugs be cleaned?
Yes, you can clean spark plugs, but in most cases its not worth it.
We do not recommend it for a number of reasons. In short, you will not get the same performance from a cleaned plug as a new plug. This is because electricity likes sharp edges to discharge from, a used plug will already have wear, and cleaning may contribute to that wear even more. (depending on the cleaning method used) If you want to try it, the below cleaning procedure was supplied by an old motor head. Good luck!
If the firing end is wet, make sure you clean the spark plug with a quick drying cleaner. (Examples: contact cleaner or brake cleaner).
Sand blast the spark plug using low air pressure and use a dry compound.
Completely blow all the sand from the spark plug.
Using a wire brush clean the threads and re-gap.
NOTE: Insufficient cleaning of the spark plug may lead to spark plug failure in a very short period of time. Clean the spark plug thoroughly to avoid problems later. Remember, if a spark plug is fouling it's usually a result of engine side factors or incorrect heat range selection.
How do I find a colder or hotter plug?
First, consult the NGK numbering system, you should be able to see which digits identify the heat range for your spark plug.
EXAMPLE: The heat range for a BCPR6ES-11 is the "6" (ignore the -11, it is the gap)
After you have identified the numbering system for your plug, merely raise or lower that number to change the heat range.
REMEMBER, NGK PLUGS GET COLDER THE HIGHER THE NUMBER, HOTTER THE LOWER THE NUMBER.
Say you are starting with a BKR6E-11
if you want a colder plug, you would use BKR7E-11
if you want a hotter plug, you would use BKR5E-11
(again, on non-racing plugs, the number after the "-" refers to the gap)
RACING PLUGS ARE AN EXCEPTION
Any NGK spark plug that starts with an “R” is a racing plug (it is important you note we said it starts with an “R”, not that it has an “R” in it) For the NGK racing plugs, the heat range is after the dash IE: R5671A-10 is a 10 heat range. You can change heat ranges on racing plugs merely by raising or lowering the last digit.
If you are trying to go hotter on an R5671A-10
you would lower the last digit, you want an R5671A-9
If you are trying to go colder on an R5671A-10
you would raise the last digit, you want an R5671A-11
In the NGK racing plugs, there are some plugs in which 1/2 heat ranges are available. These are displayed as a 3 digit heat range. An example is an R6120-105, this would more readily be understood as a 10.5 heat range(10 1/2 heat range)
Keywords: spark plug plugs NGK laser pulse copper iridium platinum v-power fuel economy electrode review fouling bridging quenching deposits ignition coils.
I personally haven't found any single thread on the forums that goes through a comprehensive explanation relating to spark plugs. I've been sifting through a ton of scattered information and decided to make a thread to organize it all. NGK plugs are focused on, should be helpful since the consensus appears to be NGK for our Maximas.
Anatomy of a Spark Plug
How does a spark plug work?
The spark plug forces electricity to arc across a gap, just like a bolt of lightning. This spark ignites gas/air mixture in the cylinder to create a controlled explosion/combustion. This combustion force pushes the cylinder downwards to power the engine. The electricity must be at a very high voltage in order to travel across the gap and create a good spark. Voltage at the spark plug can be anywhere from 40,000 to 100,000 volts.
The spark plug must have an insulated passageway for this high voltage to travel down to the electrode, where it can jump the gap and, from there, be conducted into the engine block and grounded. The plug also has to withstand the extreme heat and pressure inside the cylinder, and must be designed so that deposits from fuel additives do not build up on the plug.
Spark plugs use a ceramic insert to isolate the high voltage at the electrode, ensuring that the spark happens at the tip of the electrode and not anywhere else on the plug; this insert does double-duty by helping to burn off deposits. Ceramic is a fairly poor heat conductor, so the material gets quite hot during operation. This heat helps to burn off deposits from the electrode.
Some cars require a hot plug. This type of plug is designed with a ceramic insert that has a smaller contact area with the metal part of the plug. This reduces the heat transfer from the ceramic, making it run hotter and thus burn away more deposits. Cold plugs are designed with more contact area, so they run cooler. Car manufacturers will designate the correct temperature plug for each car. Cars with high-performance engines naturally generate more heat, so they need colder plugs.
Types of Electrodes
Spark plugs with fine wire center electrodes operate better for two reasons. First, a smaller center electrode requires less voltage to jump the gap. This means fewer misfires, which will be seen in higher mileage and more horsepower. The second reason is smaller center electrodes reduce quenching. The smaller center electrodes have required exotic metals such as platinum or iridium so that they can still maintain (and sometimes surpass) the longevity of a traditional spark plug. NGK makes both platinum fine wire (1.1mm diameter center electrode) plugs and Iridium ultra-fine wire (0.7mm diameter center electrode), a traditional center electrode is typically 2.0 to 2.5mm.
V-Power spark plugs are a patented design by NGK. Ignitability is improved by the V-groove cut in the center electrode parallel to the ground electrode, this directs the spark to to the edge of the center electrode thus exposing it to more of the air/fuel mixture. Quenching is reduced in much the same manner, drawing the spark to the edge of the center and ground electrodes reduces the surface area available to quench the spark. See quenching for more info.
Traditional center electrode
Taper cut center electrode
Fine wire platinum
Ultra fine wire iridium
V-Power
Heat range
The term spark plug heat range refers to the speed with which the plug can transfer heat from the combustion chamber to the engine head. Whether the plug is to be installed in a boat, lawnmower or racecar, it has been found the optimum combustion chamber temperature for gasoline engines is between 500°C–850°C. When it is within that range it is cool enough to avoid pre-ignition and plug tip overheating (which can cause engine damage), while still hot enough to burn off combustion deposits which cause fouling.
The spark plug can help maintain the optimum combustion chamber temperature. The primary method used to do this is by altering the internal length of the core nose, in addition, the alloy compositions in the electrodes can be changed. This means you may not be able to visually tell a difference between heat ranges. When a spark plug is referred to as a “cold plug”, it is one that transfers heat rapidly from the firing tip into the engine head, which keeps the firing tip cooler. A “hot plug” has a much slower rate of heat transfer, which keeps the firing tip hotter.
An unaltered engine will run within the optimum operating range straight from the manufacturer, but if you make modifications such as a turbo, supercharger, increase compression, timing changes, use of alternate racing fuels, or sustained use of nitrous oxide, these can alter the plug tip temperature and may necessitate a colder plug. A rule of thumb is, one heat range colder per modification or one heat range colder for every 75–100hp you increase. In identical spark plug types, the difference from one full heat range to the next is the ability to remove 70°C to 100°C from the combustion chamber.
The heat range numbers used by spark plug manufacturers are not universal, by that we mean, a 10 heat range in Champion is not the same as a 10 heat range in NGK nor the same in Autolite. Some manufacturers numbering systems are opposite the other, for domestic manufacturers (Champion, Autolite, Splitfire), the higher the number, the hotter the plug.
For Japanese manufacturers (NGK, Denso), the higher the number, the colder the plug.
http://www.ngk.com/glossaryImages/721.jpg
Do not make spark plug changes at the same time as another engine modification such as injection, carburetion or timing changes as in the event of poor results, it can lead to misleading and inaccurate conclusions (an exception would be when the alternate plugs came as part of a single precalibrated upgrade kit). When making spark plug heat range changes, it is better to err on the side of too cold a plug. The worst thing that can happen from too cold a plug is a fouled spark plug, too hot a spark plug can cause severe engine damage
Common Types of Plug Failure
More Extensive List/Pics here (hint: zoom in)....http://img.photobucket.com/albums/v2...n22/img017.jpg
Fouling
Fouling occurs when the spark plugs' firing tip becomes coated with excessive fuel, oil, or combustion deposits so that it is unable to produce a spark. A plug can become fouled from continuous low speed driving, improper spark plug heat range (too cold), improper timing (over-retarded), too rich an air/fuel ratio or an oil leak into the combustion chamber. A variety of self-cleaning features are designed into most plugs to reduce fouling.
wet fouling image
dry fouling
Bridging
Bridging happens when deposits accumulate between the center electrode and the outer shell or base of the ground electrode. These deposits can form a "bridge" for an improper spark path from the center electrode to the outer shell. The accumulation of deposits on the firing end can be caused by oil leakage, fuel quality and the engine's operating duration. Depending on the application, there are a variety of self cleaning designs used by NGK to reduce bridging.
Pre-ignition
Ignition of the air/fuel mixture prior to its timed ignition by a spark from the spark plug is referred to as "pre-ignition". This can be caused by a hot spot in the combustion chamber, improper timing, too hot a spark plug, low octane fuel, too lean an air/fuel mixture, or engine overheating.
Flashover
Flashover is when the voltage sent to the spark plug does not fire between the center and ground electrodes within the combustion chamber. Instead, it shorts between the metal shell and the terminal nut on the plug exterior, causing the engine to misfire. This can occur when the air is highly ionized (such as on a stormy day), or when the insulator is dirty. Ribbed corrugations on the top portions of the insulator can reduce flashover.
Quenching
Quenching is when the heat generated by the spark is absorbed by the center or ground electrodes instead of igniting the air/fuel mixture. To understand quenching and how it is reduced it is first necessary to review the basic purpose of the spark plug is to ignite the air fuel mixture in the combustion chamber. To do this your vehicle ignition system generates tens of thousands of volts to jump the gap between the center and ground electrodes. However it is good to know that it is not the actual electricity that ignites the air fuel mixture, it is the heat energy generated by that electricity or spark. Therefore when you are creating the spark you want as much of the heat from that spark to be used to ignite the air fuel mixture and not have the heat from that spark be re-absorbed by the center and ground electrodes. Cut back ground electrodes, V-groove center electrodes, fine wire center and ground electrodes all resist quenching by reducing the surface area between the electrodes and the flame nucleus.
The NGK Lineup
Standard: Copper standard plugs offer heat-range tunability with OEM-Spec manufacturing quality and excellent product reliability standards.
V-Power: Like the standard plugs with a groove in the center electrode. Modern lean-burning, fuel efficient engines create a new set of requirements for spark plugs. NGK Spark Plugs answered the call for a spark plug with lower sparking voltage requirements by developing the V-Power, the only spark plug with a v-groove center electrode on the market today. Why is this important? The v-groove center electrode on a V-Power spark plug forces the spark to the outer edge of the ground electrode, placing it closer to the air/fuel mixture. What this does is allow the spark to more quickly ignite the mixture, providing more complete combustion. More complete combustion not only provides more power, it also means less harmful emissions. These emissions are not only damaging to the environment, they can reduce the life of expensive catalytic converters and oxygen sensors. V-Power Spark Plugs also require lower ignition firing voltage, resulting in quicker starts and easier cold weather starts throughout the life of the plugs. NGK V-Power Spark Plugs also are ideally suited for race cars and high performance street cars. Today's performance engines are high compression/high stress applications. Many are supercharged, turbo-charged or nitrous oxide fed. NGK's patented v-groove design allows the ignition system to easily spark in these dense air/fuel mixtures. The flame kernel will quickly grow and allow the engine to potentially make more power since it now is operating more efficiently. As an added bonus, the v-groove forcing the spark to the outer edge of the ground electrode helps reduce the "quenching" effect, reducing misfires caused by high cylinder pressures "blowing out" the spark.
G-Power Platinum: Another precious metal just became more affordable. The G-Power Platinum Spark Plug is designed to deliver the power, performance and quality at a very competitive price. (typically $3/ea) The G-Power Spark Plug features an extremely fine center electrode of platinum combined with a sharp pointed ground electrode designed for better igniting performance. When compared to conventional plugs, the result is a spark plug that delivers better starts, acceleration and greater fuel economy.
Platinum: The platinum material on the center and ground electrode is harder than copper and resists wear. Owners enjoy the extended miles between plug replacement. Seems to be the middle man between performance and plug life. Manufacturer recommends these NOT be used with nitrous.
Iridium IX: Features a 0.6 mm iridium center electrode tip, they offer improved ignitability without sacrificing durability. The tapered ground electrode increases flame kernel expansion, while the superior heat range design is can meet the demands of higher performance. Offer improved acceleration and high fuel efficiency and long life. However, I've read a number of user reviews that suggest these plugs wear out faster than platinums despite iridium being 7x harder than platinum. (Maybe due to thinner layer used secondary to increased cost of metal?)
Laser Iridium/ Laser Platinum Plugs: Laser welding process that provides a 360° seal so the electrode resists wear even in the worst conditions. Supposedly causes engines to run cleaner by using less fuel and more air, which in turn improves engine performance while lowering emissions.
Metal Properties Comparison Chart
Common Questions
Can I use Iridium plugs with nitrous injection or a blown alcohol motor?
Yes, and Yes.
We double checked with the tech’s on this one, they say, while they have been watching for problems, thus far, there has been no reports of any problems in using iridium plugs with a nitrous system.
There should not be any problems using Iridium with a blown alcohol motor
Should I gap my Iridium Plugs?
The manufacturers say NO.
This is because most people do not know how to properly gap a spark plug, and the center electrodes on the ultra-fine iridium can easily snap if mishandled. There is no warranty for snapped center electrodes. The manufacturers say an iridium spark plug will run so much better than a traditional plug, even if it is not gapped for that motor, that they would prefer you just leave it rather than risk snapping the center electrode.
How long will my Iridium spark plugs last?
A traditional iridium plug such as a ZFR6FIX-11 has an iridium center electrode, however the ground electrode is the traditional nickel construction. The ground electrode will wear out first. The manufacturers of Irdium plugs are saying 40,000 to 60,000 miles. But they have to temper their projections as driving conditions and motor modifications differ. Typically we have found you can expect 60,000 to 80,000 miles on anunaltered motor. (the wife’s mini-van has had Iridiums for 76,000 miles, I examined 2 of the plugs, they had some minor wear on the ground electrode, I put them back in and will likely change them in another 5,000 miles)
Some NGK Iridium racing plugs have iridium center and a platinum ground electrodes. If installed to a regular engine they would likely last longer than most people keep their car (barring any motor problems that can cause premature plug death). But, these usually come in heat ranges too cold for an unaltered motor and are usually used in racing applications where all bets are off.
For the traditional automotive market, the longest lasting plugs are the NGK "IFR" series. These have Iridium center and platinum tipped ground electrodes, however these are extremely limited in application as they only manufactured these in a couple of heat range configurations.
Can I use platinum plugs with nitrous injection?
No, it is not suggested to use platinum plugs with nitrous oxide injection.
There have been instances where the platinum tip has lost its bond to either the center or ground electrode when they were used in a motor with nitrous.
Thus far tech's say they have had no problems using Iridium plugs with nitrous.
Can old spark plugs be cleaned?
Yes, you can clean spark plugs, but in most cases its not worth it.
We do not recommend it for a number of reasons. In short, you will not get the same performance from a cleaned plug as a new plug. This is because electricity likes sharp edges to discharge from, a used plug will already have wear, and cleaning may contribute to that wear even more. (depending on the cleaning method used) If you want to try it, the below cleaning procedure was supplied by an old motor head. Good luck!
If the firing end is wet, make sure you clean the spark plug with a quick drying cleaner. (Examples: contact cleaner or brake cleaner).
Sand blast the spark plug using low air pressure and use a dry compound.
Completely blow all the sand from the spark plug.
Using a wire brush clean the threads and re-gap.
NOTE: Insufficient cleaning of the spark plug may lead to spark plug failure in a very short period of time. Clean the spark plug thoroughly to avoid problems later. Remember, if a spark plug is fouling it's usually a result of engine side factors or incorrect heat range selection.
How do I find a colder or hotter plug?
First, consult the NGK numbering system, you should be able to see which digits identify the heat range for your spark plug.
EXAMPLE: The heat range for a BCPR6ES-11 is the "6" (ignore the -11, it is the gap)
After you have identified the numbering system for your plug, merely raise or lower that number to change the heat range.
REMEMBER, NGK PLUGS GET COLDER THE HIGHER THE NUMBER, HOTTER THE LOWER THE NUMBER.
Say you are starting with a BKR6E-11
if you want a colder plug, you would use BKR7E-11
if you want a hotter plug, you would use BKR5E-11
(again, on non-racing plugs, the number after the "-" refers to the gap)
RACING PLUGS ARE AN EXCEPTION
Any NGK spark plug that starts with an “R” is a racing plug (it is important you note we said it starts with an “R”, not that it has an “R” in it) For the NGK racing plugs, the heat range is after the dash IE: R5671A-10 is a 10 heat range. You can change heat ranges on racing plugs merely by raising or lowering the last digit.
If you are trying to go hotter on an R5671A-10
you would lower the last digit, you want an R5671A-9
If you are trying to go colder on an R5671A-10
you would raise the last digit, you want an R5671A-11
In the NGK racing plugs, there are some plugs in which 1/2 heat ranges are available. These are displayed as a 3 digit heat range. An example is an R6120-105, this would more readily be understood as a 10.5 heat range(10 1/2 heat range)
Keywords: spark plug plugs NGK laser pulse copper iridium platinum v-power fuel economy electrode review fouling bridging quenching deposits ignition coils.
Last edited by mannetti21; Apr 6, 2009 at 06:36 AM.
Original post updated with more extensive list/pics of normal plug wear and additional types of failure.
(hint: zoom in)....http://img.photobucket.com/albums/v2...n22/img017.jpg
(hint: zoom in)....http://img.photobucket.com/albums/v2...n22/img017.jpg
good job, i need to replace mine again.
So would i get a colder or hotter plug to help reduce pinging ? and i always use the highest octane fuel i can get at any gas station.
So would i get a colder or hotter plug to help reduce pinging ? and i always use the highest octane fuel i can get at any gas station.
Last edited by Professor; Mar 24, 2009 at 01:24 PM.
The higher octane will obviously help, but if the plugs get too hot they can fire off the air/fuel mixture at the wrong time, thus some possible pinging. A colder plug may work, give it a shot.
Do you recommend a part number ? I have a 2000 Max, VQ30.
i currently have what the OEM calls for,
Last edited by Professor; Mar 24, 2009 at 01:39 PM.
Not sure if switching to a colder plug would be the first step in eliminating ping though. I certainly am unaware of everything that would come before, but maybe someone else could chime in on this.
Just a heads up, I bought 6 NGK iridium IX today and gap is supposed to be .044 per NGK, although Nissan calls for .043....so I checked each of them and the gaps varied between .041-.043
So probably a good idea to not rely on "pre-gapped" specs from the manufacturer, and just DIY.
So probably a good idea to not rely on "pre-gapped" specs from the manufacturer, and just DIY.
Last edited by mannetti21; Mar 24, 2009 at 10:18 PM.
Member
Joined: Mar 2007
Posts: 96
Any advantage usinig Iridium plugs? or should I just stick with platinum?
I am doing a tune up on my 2000 SE with 75k miles, besides plugs and testing/replacing ignition coils (if needed). Changing PCV valve and checking vacumm lines. Before all that running some seafoam.
What else should I put in the to do list.
Thanks a lot
I am doing a tune up on my 2000 SE with 75k miles, besides plugs and testing/replacing ignition coils (if needed). Changing PCV valve and checking vacumm lines. Before all that running some seafoam.
What else should I put in the to do list.
Thanks a lot
Senior Member
Joined: May 2008
Posts: 1,767
From: Moore, OK
Damn, he just copy pasted from other websites.....blah
http://auto.howstuffworks.com/ignition-system2.htm
http://auto.howstuffworks.com/ignition-system2.htm
Member
Joined: Mar 2007
Posts: 96
Damn, he just copy pasted from other websites.....blah
Now again, what would be better iridium or platinum?? what else do I need for tune up.
Damn, he just copy pasted from other websites.....blah
http://auto.howstuffworks.com/ignition-system2.htm
http://auto.howstuffworks.com/ignition-system2.htm
I personally haven't found any single thread on the forums that goes through a comprehensive explanation relating to spark plugs. I've been sifting through a ton of scattered information and decided to make a thread to organize it all. NGK plugs are focused on, should be helpful since the consensus appears to be NGK for our Maximas.
Senior Member
Joined: May 2008
Posts: 1,767
From: Moore, OK
Yeah, because we get so many threads about a friggin spark plug that we need to have a post that is 2000 words long. This is basic automotive crap here. Who the hell needs comprehensive information about a spark plug? Seriously?!
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