READING SPARK PLUGS AT THE TRACK:
There is a lot of mystery into this" black art" of racing.
A lot of this mystery will be figured out if you use a Spark Plug that shows color when you start timing and fuel/air adjustments.
Many times I have checked as recently as last weekend a racing team doing plug checks with a brand that I know does not show combustion color! it was either real clean or fouled !
To make matters worse they where doing plug readings with old plugs that had a bunch of passes on it.
So here we are to clear up the mystery and start from scratch.
Pictured above is an NGK that was used on two runs on a 250 shot of Nitrous ! (8.40@154 MPH and 950 horsepower).
The reason I use NGK's is it shows color as I change air/fuel or timing adjustments. Other makes out there also has this capability.
Upon close inspection you can see a "slight tan and light brown" color. This signifies a safe and conservative tune to this engine, it is neither too dark or too light or what they call "clean".
When its too light or clean get ready because its going to clean your wallet ! It will eventually lean out and wipe out a piston and worse scratch the cylinder walls.
The center electrode upon close observation has brown specs at its center, this is not bad as this is from the driver lifting suddenly from a full throttle pass and colored the center.
What this driver should have done is " Cut-off" clean on top-end and coast, and then get towed back to the pits to pull and read the plugs.
What you should be looking for are little "aluminum specs" and or dark round black specs scattered on the center electrode, this are pieces of piston material melting on a lean run....
Second is look at the ground strap and see if the corners are starting to roll over at the edges ! This is another indication of lean.
Pay attention to this area where the spark is actually jumping to the center electrode.
The center electrode should be of brown or light brown for a safe nitrous or turbo run. Also check for the rounding off of the tips and that is an indication of melting.
Normally aspirated: Look for a ground strap coloring of tan to light brown and getting darker as it goes to the spark plug ring, center electrode should be again tan-light brown. The crown should be the same with out any specs of aluminum or dark specs all over the center electrode. This will be as close to your timing and Air/fuel you will get.
Extreme Boost levels: I usually set up more on the darker side of coloring almost about to look like its real rich and this is just an insurance on an engine that is capable of 7-6 second runs.
(1000+ HP)
The reason for this is I run rich on this set-up to suppress detonation or pre-ignition conditions from forming secondary ignition sources that will surely destroy a boosted engine.
In doing this the extra fuel acts as a coolant.....
TRACK TIPS:+++++++++++++++++++++++++++++
WHAT DO YOU DO WHEN YOU ARE AT THE EDGE OF YOUR TUNING WINDOW?
( run out of adjustments-pump press/volume,timing & jetting) ?
YOUR SPARK PLUGS SHOWING A LITTLE MELTING AROUND THE EDGES AND A LIGHT COLOR ON THE PLUGS?
DESPERATE TIMES REQUIRE DESPERATE MEASURES !!!
FIRST REMOVE SPARK PUGS AND SHORTEN THE GROUND STRAP KEEPING IN MIND THAT THIS WILL MAKE IT RUN AND FUNCTION COOLER AND PREVENTS IT FROM MELTING AND OVERHEATING.
(shorter ground straps runs cooler)
THIS IS ONE REASON RACING SPARK PLUGS HAVE A SHORTER STRAP THAT REACHES HALFWAY TO THE CENTER ELECTRODE SAME LIKE THE PICTURE ABOVE, YOU CAN STILL SHORTEN THIS, AND GAP ON THE SIDE !
SECOND OPTION IS TO ADD WASHERS TO THE SPARK PLUG SEAT, THIS WILL RETRACT THE SPARK PLUG INTO THE CHAMBER AND MAKE THE TIP COOLER AS IT IS "LESS" EXPOSED TO THE FLAME/IGNITION FRONT. THIS ALSO INCREASES THE CHAMBER VOLUME AND DECREASES THE COMPRESSION RATIO A BIT.
AND LAST IF YOU ARE RUNNING A STANDARD PLUG, YOU CAN CUT THE GROUND STRAP SHORTER AND RE-BEND THIS AND GAP IT ON THE SIDES.
NOW IT IS LIKE A RACING SPARK PLUG WHERE THE IGNITION EMANATES NOT FROM UNDER AND BETWEEN THE GAP BUT OUT IN THE OPEN TOWARDS THE PISTON TOP....
THIS WORKS ! RACE SAFE FRIENDS !!!
Check the next article on Spark Plugs here at PARA !
BEN ALAMEDA@PARA,FB, BENALAMEDARACING.COM
( tech. articles in memory of Chuck Stevens: Mentor & Friend )
There is a lot of mystery into this" black art" of racing.
A lot of this mystery will be figured out if you use a Spark Plug that shows color when you start timing and fuel/air adjustments.
Many times I have checked as recently as last weekend a racing team doing plug checks with a brand that I know does not show combustion color! it was either real clean or fouled !
To make matters worse they where doing plug readings with old plugs that had a bunch of passes on it.
So here we are to clear up the mystery and start from scratch.
Pictured above is an NGK that was used on two runs on a 250 shot of Nitrous ! (8.40@154 MPH and 950 horsepower).
The reason I use NGK's is it shows color as I change air/fuel or timing adjustments. Other makes out there also has this capability.
Upon close inspection you can see a "slight tan and light brown" color. This signifies a safe and conservative tune to this engine, it is neither too dark or too light or what they call "clean".
When its too light or clean get ready because its going to clean your wallet ! It will eventually lean out and wipe out a piston and worse scratch the cylinder walls.
The center electrode upon close observation has brown specs at its center, this is not bad as this is from the driver lifting suddenly from a full throttle pass and colored the center.
What this driver should have done is " Cut-off" clean on top-end and coast, and then get towed back to the pits to pull and read the plugs.
What you should be looking for are little "aluminum specs" and or dark round black specs scattered on the center electrode, this are pieces of piston material melting on a lean run....
Second is look at the ground strap and see if the corners are starting to roll over at the edges ! This is another indication of lean.
Pay attention to this area where the spark is actually jumping to the center electrode.
The center electrode should be of brown or light brown for a safe nitrous or turbo run. Also check for the rounding off of the tips and that is an indication of melting.
Normally aspirated: Look for a ground strap coloring of tan to light brown and getting darker as it goes to the spark plug ring, center electrode should be again tan-light brown. The crown should be the same with out any specs of aluminum or dark specs all over the center electrode. This will be as close to your timing and Air/fuel you will get.
Extreme Boost levels: I usually set up more on the darker side of coloring almost about to look like its real rich and this is just an insurance on an engine that is capable of 7-6 second runs.
(1000+ HP)
The reason for this is I run rich on this set-up to suppress detonation or pre-ignition conditions from forming secondary ignition sources that will surely destroy a boosted engine.
In doing this the extra fuel acts as a coolant.....
TRACK TIPS:+++++++++++++++++++++++++++++
WHAT DO YOU DO WHEN YOU ARE AT THE EDGE OF YOUR TUNING WINDOW?
( run out of adjustments-pump press/volume,timing & jetting) ?
YOUR SPARK PLUGS SHOWING A LITTLE MELTING AROUND THE EDGES AND A LIGHT COLOR ON THE PLUGS?
DESPERATE TIMES REQUIRE DESPERATE MEASURES !!!
FIRST REMOVE SPARK PUGS AND SHORTEN THE GROUND STRAP KEEPING IN MIND THAT THIS WILL MAKE IT RUN AND FUNCTION COOLER AND PREVENTS IT FROM MELTING AND OVERHEATING.
(shorter ground straps runs cooler)
THIS IS ONE REASON RACING SPARK PLUGS HAVE A SHORTER STRAP THAT REACHES HALFWAY TO THE CENTER ELECTRODE SAME LIKE THE PICTURE ABOVE, YOU CAN STILL SHORTEN THIS, AND GAP ON THE SIDE !
SECOND OPTION IS TO ADD WASHERS TO THE SPARK PLUG SEAT, THIS WILL RETRACT THE SPARK PLUG INTO THE CHAMBER AND MAKE THE TIP COOLER AS IT IS "LESS" EXPOSED TO THE FLAME/IGNITION FRONT. THIS ALSO INCREASES THE CHAMBER VOLUME AND DECREASES THE COMPRESSION RATIO A BIT.
AND LAST IF YOU ARE RUNNING A STANDARD PLUG, YOU CAN CUT THE GROUND STRAP SHORTER AND RE-BEND THIS AND GAP IT ON THE SIDES.
NOW IT IS LIKE A RACING SPARK PLUG WHERE THE IGNITION EMANATES NOT FROM UNDER AND BETWEEN THE GAP BUT OUT IN THE OPEN TOWARDS THE PISTON TOP....
THIS WORKS ! RACE SAFE FRIENDS !!!
Check the next article on Spark Plugs here at PARA !
BEN ALAMEDA@PARA,FB, BENALAMEDARACING.COM
( tech. articles in memory of Chuck Stevens: Mentor & Friend )
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