Reading a plug

k9

Dragway Regular
May 22, 2003
1,122
0
0
CHICAGO
Went to the track for the first time yesterday. Only got to make one full pass and found out that I closed the gap on most of the plugs-needed to index the plugs-lesson learned
It went 11.15/122
Anyhow, my question is,how do you properly read a plug? What color should I be looking for and where should I be looking? I can take a few pics if somebody can post them.
 

boyzbad

Top Fueler
Jul 28, 2004
2,637
0
0
Olathe, Ks
You'll want to look down in at the base of the porcelin. It's been a while for me runnig gas but I believe you want a lighter greyish color.
 

k9

Dragway Regular
Thread starter
May 22, 2003
1,122
0
0
CHICAGO
I have a grey color at the base, but I dont know if it would be considered lean or rich. I am going to take them to one of my customers who races a pro-mod and maybe learn a few things :)
 
A

Anonymous

Guest
k9 said:
Went to the track for the first time yesterday. Only got to make one full pass and found out that I closed the gap on most of the plugs-needed to index the plugs-lesson learned
It went 11.15/122
Anyhow, my question is,how do you properly read a plug? What color should I be looking for and where should I be looking? I can take a few pics if somebody can post them.

email me the pics
 
A

Anonymous

Guest
here you go.

spark_plug.jpg
 
A

Anonymous

Guest
Looks like its running decent. I would like to see a new plug with one pass on it and a better pic.
What you are looking for is the fuel ring in the middle of the porcelin and where the heat is on the ground strap and electrode. If you go over to yellowbullet.com Monty has a killer write up on nos plugs with pics. good read but the timing part will be different for you.
heres a link : http://www.yellowbullet.com/forum/showthread.php?t=7255
 
A

Anonymous

Guest
here's a even better link i found : http://www.dragstuff.com/techarticles/how-to-read-plugs.html
 
A

Anonymous

Guest
K9, what type and brand fuel are you using? I agree with Bigtime it dose look pretty good but to read them right you have to look down deep in the plug. The tip is just idle ratio. Different fuels like Torco and some VP's look different on the plug. You can also look inside the pipes. You want a light grey color. Dark is too rich and white too lean. To get a perfect read on the plugs you really need to shut the car off at the end of the run and coast to the end of the track. Some do but not me!
 

Jordan81

Pro Stocker
Feb 10, 2004
1,774
0
0
wichita, ks
http://www.4secondsflat.com/Spark_plug_reading.html
 

k9

Dragway Regular
Thread starter
May 22, 2003
1,122
0
0
CHICAGO
Thank you guys. I ran VP C12 with a Pro Systems carb with 88 jets squared. I couldnt provide a better picture because of lighting. I have the timing set at 38. I made two passes on those plugs so I know you cant get an accurate reading.
 

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