DirtyEP3
10-31-2007, 10:40 AM
maybe a sticky on this. plz.
K series plug info:
Thread size = 14mm
Resistor Type
Thread reach = 19mm
Electrode = Iridium
Gap = 1.1mm (0.044") - Iridium plugs come pre-gapped!!
Brand
Part Number - Heat range
Denso Iridium
SKJ20DR-M11 - stock (A3)
IK20 - stock (A3)
SK22PR-M11 - 1 step colder (A3) - stock (A2)
IK22 - 1 step colder (A3) - stock (A2)
IK24 - 2 steps colder (A3) - 1 step colder (A2)
NGK Iridium
See this link for part number meanings:
http://www.ngk.com/sparkplug411_ngk.asp
IZFR6-K11 - stock (A3)
BKR6EIX - stock (A3)
IFR7G-11KS - 1 step colder (A3) - stock (A2)
BKR7EIX - 1 step colder (A3) - stock (A2)
BKR8EIX - 2 steps colder (A3) - 1 step colder (A2)
Side note on spark plug part numbers...
Notice the magic numbers in the part # above; they are the heat ranges for those brands.
Denso - 20, 22, 24
NGK - 6, 7, 8
What does colder plugs mean?
The temperature of the spark plug's firing end must be kept low enough to prevent pre-ignition, but high enough to prevent fouling. This is called "Thermal Performance", and is
determined by the heat range selected.
It's important to remember spark plugs do not create heat, they only remove heat. The spark plug works as a heat exchanger
by pulling unwanted thermal energy away from the combustion chamber, and transferring the heat to the engine's cooling
system. The heat range is defined as a plug's ability to
dissipate heat.
The rate of heat transfer is determined by:
The insulator nose length
Gas volume around the insulator nose
The materials/construction of the center electrode and porcelain insulator
A spark plug's heat range has no relationship to the actual voltage transferred through the spark plug. Rather, the heat range is a measure of the spark plug's ability to remove heat from the combustion chamber. The heat range measurement is determined by several factors; the length of the ceramic center insulator nose and its' ability to absorb and transfer combustion heat, the material composition of the insulator and center electrode material.
Heat rating and heat flow path of NGK Spark Plugs
The insulator nose length is the distance from the firing tip of the insulator to the point where insulator meets the metal shell. Since the insulator tip is the hottest part of the spark plug, the tip temperature is a primary factor in pre-ignition and fouling. Whether the spark plugs are fitted in a lawnmower, boat, or a race car, the spark plug tip temperature must remain between 500C-850°C. If the tip temperature is lower than 500°C, the insulator area surrounding the center electrode will not be hot enough to burn off carbon and combustion chamber deposits. These accumulated deposits can result in spark plug fouling leading to misfire. If the tip temperature is higher than 850°C the spark plug will overheat which may cause the ceramic around the center electrode to blister and the electrodes to melt. This may lead to pre-ignition/detonation and expensive engine damage. In identical spark plug types, the difference from one heat range to the next is the ability to remove approximately 70°C to 100°C from the combustion chamber. A projected style spark plug firing tip temperature is increased by 10°C to 20°C.
What else can you tell me about spark plugs?
Spark plugs are one of the most misunderstood components
of an engine. Numerous questions have surfaced over the years, leaving many people confused.
This guide is designed to assist the technician, hobbyist, or race mechanics in understanding, using, and troubleshooting spark plugs. The information contained in this guide applies to
all types of internal combustion engines.
Spark plugs are the "window" into the engine , and can be used as a valuable diagnostic tool. Like a patient's thermometer, the spark plug displays symptoms and conditions of the engine. The experienced tuner can analyze these symptoms to track down the root cause of many problems, or determine air/fuel ratios.
SPARK PLUG BASICS:
The spark plug has two primary functions:
-Ignite air/fuel mixture
-Transfer heat from the combustion chamber
Spark plugs carry electrical energy and turn fuel into working energy. A sufficient amount of voltage must be supplied by the ignition system to spark across the spark plug's gap. This is
called "Electrical Performance."
Below is a list of external influences on a spark plug's operating temperature. The following symptoms or conditions may have an effect on the actual temperature of the spark plug. The spark plug cannot create these conditions, but it must be able to cope with the levels of heat...if not, the performance will suffer and engine damage can occur.
Air/Fuel Mixtures seriously affect engine performance and spark plug operating temperatures.
Rich air/fuel mixtures cause tip temperature to drop, causing fouling and poor driveability
Lean air/fuel mixtures cause plug tip and cylinder temperature to increase, resulting in pre-ignition, detonation, and possibly serious spark plug and engine damage
It is important to read spark plugs many times during the tuning process to achieve the optimum air/ fuel mixture
Higher Compression Ratios/Forced Induction will elevate spark plug tip and in-cylinder temperatures
Compression can be increased by performing any one of the following modifications:
a) reducing combustion chamber volume (i.e.: domed pistons, smaller chamber heads, mill ing heads, etc.)
b) adding forced induction (Nitrous, Turbocharging or Supercharging)
c) camshaft change
As compression increases, a colder heat range plug, higher fuel octane, and careful attention to ignition timing and air/fuel ratios are necessary. Failure to select a colder spark plug can lead to spark plug/engine damage
Advancing Ignition Timing
Advancing ignition timing by 10° causes tip temperature to increase by approx. 70°-100° C
Engine Speed and Load
Increases in firing-end temperature are proportional to engine speed and load. When traveling at a consistent high rate of speed, or carrying/pushing very heavy loads, a colder heat range spark plug should be installed
Ambient Air Temperature
As air temperature falls, air density/air volume becomes greater, resulting in leaner air/fuel mixtures.
This creates higher cylinder pressures/temperatures and causes an increase in the spark plug's tip temperature. So, fuel delivery should be increased.
As temperature increases, air density decreases, as does intake volume, fuel delivery should be decreased
Humidity
As humidity increases, air intake volume decreases
Result is lower combustion pressures and temperatures, causing a decrease in the spark plug's temperature and a reduction in available power.
Air/fuel mixture should be leaner, depending upon ambient temperature.
Barometric Pressure/Altitude
Also affects the spark plug's tip temperature
The higher the altitude, the lower cylinder pressure becomes. As the cylinder temperature decreases, so does the plugs tip temperature
Many mechanics attempt to "chase" tuning by changing spark plug heat ranges
The real answer is to adjust air/fuel mixtures by rejetting in an effort to put more air back into the engine
Types of Abnormal Combustion
Pre-ignition
Defined as: ignition of the air/fuel mixture before the pre-set ignition timing mark
Caused by hot spots in the combustion chamber...can be caused
(or amplified) by over advanced timing, too hot a spark plug, low octane fuel, lean air/fuel mixture, too high compression, or insufficient engine cooling
A change to a higher octane fuel, a colder plug, richer fuel mixture,
or lower compression may be in order
You may also need to retard ignition timing, and check vehicle's cooling system
Pre-ignition usually leads to detonation; pre-ignition an detonation are two separate events
Detonation
The spark plug's worst enemy! (Besides fouling)
Can break insulators or break off ground electrodes
Pre-ignition most often leads to detonation
Plug tip temperatures can spike to over 3000°F during the combustion process (in a racing engine)
Most frequently caused by hot spots in the combustion chamber.
Hot spots will allow the air/fuel mixture to pre-ignite. As the piston is being forced upward by mechanical action of the connecting rod, the pre-ignited explosion will try to force the piston downward. If the piston can't go up (because of the force of the premature explosion) and it can't go down (because of the upward mo-tion of the connecting rod), the piston will rattle from side to side. The resulting shock wave causes an audible pinging sound. This is detonation.
Most of the damage than an engine sustains when "detonating" is from excessive heat
The spark plug is damaged by both the elevated temperatures and the accompanying shock wave, or concussion
Misfires
A spark plug is said to have misfired when enough voltage has not been delivered to light off all fuel present in the combustion chamber at the proper moment of the power stroke (a few degrees before top dead center)
A spark plug can deliver a weak spark (or no spark at all) for a variety of reasons...defective coil, too much compression with incorrect
plug gap, dry fouled or wet fouled spark plugs, insufficient ignition timing, etc.
Slight misfires can cause a loss of performance for obvious reasons (if fuel is not lit, no energy is be-ing created)
Severe misfires will cause poor fuel economy, poor driveability, and can lead to engine damage
Fouling
Will occur when spark plug tip temperature is insufficient to burn off carbon, fuel, oil or other deposits
Will cause spark to leach to metal shell...no spark across plug gap will cause a misfire
Wet-fouled spark plugs must be changed...spark plugs will not fire
Dry-fouled spark plugs can sometimes be cleaned by bringing engine up to operating temperature
Before changing fouled spark plugs, be sure to eliminate root
cause of fouling
and if you dont want iriduim plugs you can use ngk bkr6e(6962) these are stock Type-S plugs. which are a step colder then stock EP3 plugs.
K series plug info:
Thread size = 14mm
Resistor Type
Thread reach = 19mm
Electrode = Iridium
Gap = 1.1mm (0.044") - Iridium plugs come pre-gapped!!
Brand
Part Number - Heat range
Denso Iridium
SKJ20DR-M11 - stock (A3)
IK20 - stock (A3)
SK22PR-M11 - 1 step colder (A3) - stock (A2)
IK22 - 1 step colder (A3) - stock (A2)
IK24 - 2 steps colder (A3) - 1 step colder (A2)
NGK Iridium
See this link for part number meanings:
http://www.ngk.com/sparkplug411_ngk.asp
IZFR6-K11 - stock (A3)
BKR6EIX - stock (A3)
IFR7G-11KS - 1 step colder (A3) - stock (A2)
BKR7EIX - 1 step colder (A3) - stock (A2)
BKR8EIX - 2 steps colder (A3) - 1 step colder (A2)
Side note on spark plug part numbers...
Notice the magic numbers in the part # above; they are the heat ranges for those brands.
Denso - 20, 22, 24
NGK - 6, 7, 8
What does colder plugs mean?
The temperature of the spark plug's firing end must be kept low enough to prevent pre-ignition, but high enough to prevent fouling. This is called "Thermal Performance", and is
determined by the heat range selected.
It's important to remember spark plugs do not create heat, they only remove heat. The spark plug works as a heat exchanger
by pulling unwanted thermal energy away from the combustion chamber, and transferring the heat to the engine's cooling
system. The heat range is defined as a plug's ability to
dissipate heat.
The rate of heat transfer is determined by:
The insulator nose length
Gas volume around the insulator nose
The materials/construction of the center electrode and porcelain insulator
A spark plug's heat range has no relationship to the actual voltage transferred through the spark plug. Rather, the heat range is a measure of the spark plug's ability to remove heat from the combustion chamber. The heat range measurement is determined by several factors; the length of the ceramic center insulator nose and its' ability to absorb and transfer combustion heat, the material composition of the insulator and center electrode material.
Heat rating and heat flow path of NGK Spark Plugs
The insulator nose length is the distance from the firing tip of the insulator to the point where insulator meets the metal shell. Since the insulator tip is the hottest part of the spark plug, the tip temperature is a primary factor in pre-ignition and fouling. Whether the spark plugs are fitted in a lawnmower, boat, or a race car, the spark plug tip temperature must remain between 500C-850°C. If the tip temperature is lower than 500°C, the insulator area surrounding the center electrode will not be hot enough to burn off carbon and combustion chamber deposits. These accumulated deposits can result in spark plug fouling leading to misfire. If the tip temperature is higher than 850°C the spark plug will overheat which may cause the ceramic around the center electrode to blister and the electrodes to melt. This may lead to pre-ignition/detonation and expensive engine damage. In identical spark plug types, the difference from one heat range to the next is the ability to remove approximately 70°C to 100°C from the combustion chamber. A projected style spark plug firing tip temperature is increased by 10°C to 20°C.
What else can you tell me about spark plugs?
Spark plugs are one of the most misunderstood components
of an engine. Numerous questions have surfaced over the years, leaving many people confused.
This guide is designed to assist the technician, hobbyist, or race mechanics in understanding, using, and troubleshooting spark plugs. The information contained in this guide applies to
all types of internal combustion engines.
Spark plugs are the "window" into the engine , and can be used as a valuable diagnostic tool. Like a patient's thermometer, the spark plug displays symptoms and conditions of the engine. The experienced tuner can analyze these symptoms to track down the root cause of many problems, or determine air/fuel ratios.
SPARK PLUG BASICS:
The spark plug has two primary functions:
-Ignite air/fuel mixture
-Transfer heat from the combustion chamber
Spark plugs carry electrical energy and turn fuel into working energy. A sufficient amount of voltage must be supplied by the ignition system to spark across the spark plug's gap. This is
called "Electrical Performance."
Below is a list of external influences on a spark plug's operating temperature. The following symptoms or conditions may have an effect on the actual temperature of the spark plug. The spark plug cannot create these conditions, but it must be able to cope with the levels of heat...if not, the performance will suffer and engine damage can occur.
Air/Fuel Mixtures seriously affect engine performance and spark plug operating temperatures.
Rich air/fuel mixtures cause tip temperature to drop, causing fouling and poor driveability
Lean air/fuel mixtures cause plug tip and cylinder temperature to increase, resulting in pre-ignition, detonation, and possibly serious spark plug and engine damage
It is important to read spark plugs many times during the tuning process to achieve the optimum air/ fuel mixture
Higher Compression Ratios/Forced Induction will elevate spark plug tip and in-cylinder temperatures
Compression can be increased by performing any one of the following modifications:
a) reducing combustion chamber volume (i.e.: domed pistons, smaller chamber heads, mill ing heads, etc.)
b) adding forced induction (Nitrous, Turbocharging or Supercharging)
c) camshaft change
As compression increases, a colder heat range plug, higher fuel octane, and careful attention to ignition timing and air/fuel ratios are necessary. Failure to select a colder spark plug can lead to spark plug/engine damage
Advancing Ignition Timing
Advancing ignition timing by 10° causes tip temperature to increase by approx. 70°-100° C
Engine Speed and Load
Increases in firing-end temperature are proportional to engine speed and load. When traveling at a consistent high rate of speed, or carrying/pushing very heavy loads, a colder heat range spark plug should be installed
Ambient Air Temperature
As air temperature falls, air density/air volume becomes greater, resulting in leaner air/fuel mixtures.
This creates higher cylinder pressures/temperatures and causes an increase in the spark plug's tip temperature. So, fuel delivery should be increased.
As temperature increases, air density decreases, as does intake volume, fuel delivery should be decreased
Humidity
As humidity increases, air intake volume decreases
Result is lower combustion pressures and temperatures, causing a decrease in the spark plug's temperature and a reduction in available power.
Air/fuel mixture should be leaner, depending upon ambient temperature.
Barometric Pressure/Altitude
Also affects the spark plug's tip temperature
The higher the altitude, the lower cylinder pressure becomes. As the cylinder temperature decreases, so does the plugs tip temperature
Many mechanics attempt to "chase" tuning by changing spark plug heat ranges
The real answer is to adjust air/fuel mixtures by rejetting in an effort to put more air back into the engine
Types of Abnormal Combustion
Pre-ignition
Defined as: ignition of the air/fuel mixture before the pre-set ignition timing mark
Caused by hot spots in the combustion chamber...can be caused
(or amplified) by over advanced timing, too hot a spark plug, low octane fuel, lean air/fuel mixture, too high compression, or insufficient engine cooling
A change to a higher octane fuel, a colder plug, richer fuel mixture,
or lower compression may be in order
You may also need to retard ignition timing, and check vehicle's cooling system
Pre-ignition usually leads to detonation; pre-ignition an detonation are two separate events
Detonation
The spark plug's worst enemy! (Besides fouling)
Can break insulators or break off ground electrodes
Pre-ignition most often leads to detonation
Plug tip temperatures can spike to over 3000°F during the combustion process (in a racing engine)
Most frequently caused by hot spots in the combustion chamber.
Hot spots will allow the air/fuel mixture to pre-ignite. As the piston is being forced upward by mechanical action of the connecting rod, the pre-ignited explosion will try to force the piston downward. If the piston can't go up (because of the force of the premature explosion) and it can't go down (because of the upward mo-tion of the connecting rod), the piston will rattle from side to side. The resulting shock wave causes an audible pinging sound. This is detonation.
Most of the damage than an engine sustains when "detonating" is from excessive heat
The spark plug is damaged by both the elevated temperatures and the accompanying shock wave, or concussion
Misfires
A spark plug is said to have misfired when enough voltage has not been delivered to light off all fuel present in the combustion chamber at the proper moment of the power stroke (a few degrees before top dead center)
A spark plug can deliver a weak spark (or no spark at all) for a variety of reasons...defective coil, too much compression with incorrect
plug gap, dry fouled or wet fouled spark plugs, insufficient ignition timing, etc.
Slight misfires can cause a loss of performance for obvious reasons (if fuel is not lit, no energy is be-ing created)
Severe misfires will cause poor fuel economy, poor driveability, and can lead to engine damage
Fouling
Will occur when spark plug tip temperature is insufficient to burn off carbon, fuel, oil or other deposits
Will cause spark to leach to metal shell...no spark across plug gap will cause a misfire
Wet-fouled spark plugs must be changed...spark plugs will not fire
Dry-fouled spark plugs can sometimes be cleaned by bringing engine up to operating temperature
Before changing fouled spark plugs, be sure to eliminate root
cause of fouling
and if you dont want iriduim plugs you can use ngk bkr6e(6962) these are stock Type-S plugs. which are a step colder then stock EP3 plugs.