Spark plug color & ignition timing relationship
Thread Starter
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 786
From: Lebanon Township New Jersey
Spark plug color & ignition timing relationship
Went to Englishtown on Saturday to do some bracket racing, so I couldn't make adjustments. Conditions were very fast but I was running about 1.5 tenths and 2 mph slower than I should have been. I lost in the second round, plus 3 time shots gave me 5 runs.
This was my first time out this year. I had changed the disributor to a Pertronix HEI and I went 2 heat ranges colder on my plugs. AC Delco R43TS now, R45TS before, with the old distributor. The R45s used to be light tan. The R43s are absolutely bone white. I'm sure I need to adjust the timing to optimize it, but will that change the plug coloring? I haven't touched the carb.
This was my first time out this year. I had changed the disributor to a Pertronix HEI and I went 2 heat ranges colder on my plugs. AC Delco R43TS now, R45TS before, with the old distributor. The R45s used to be light tan. The R43s are absolutely bone white. I'm sure I need to adjust the timing to optimize it, but will that change the plug coloring? I haven't touched the carb.
Le Mans Master
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
Went to Englishtown on Saturday to do some bracket racing, so I couldn't make adjustments. Conditions were very fast but I was running about 1.5 tenths and 2 mph slower than I should have been. I lost in the second round, plus 3 time shots gave me 5 runs.
This was my first time out this year. I had changed the disributor to a Pertronix HEI and I went 2 heat ranges colder on my plugs. AC Delco R43TS now, R45TS before, with the old distributor. The R45s used to be light tan. The R43s are absolutely bone white. I'm sure I need to adjust the timing to optimize it, but will that change the plug coloring? I haven't touched the carb.
This was my first time out this year. I had changed the disributor to a Pertronix HEI and I went 2 heat ranges colder on my plugs. AC Delco R43TS now, R45TS before, with the old distributor. The R45s used to be light tan. The R43s are absolutely bone white. I'm sure I need to adjust the timing to optimize it, but will that change the plug coloring? I haven't touched the carb.
Thread Starter
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 786
From: Lebanon Township New Jersey
Thread Starter
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 786
From: Lebanon Township New Jersey
I was running 35 total before and thats where I tried to reset it. I could be off 1 or 2 degrees though. I've noticed in the past that my car is very sensitive to timing. I'm using the same fuel as usual, 93 octane.
Le Mans Master
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
Thread Starter
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 786
From: Lebanon Township New Jersey
Thanks for the responses.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
The 1 or 2 degrees can cut 1.5 tenths off especially if combined with a a couple seemingly minor variables like a little warmer temperatures, different track prep, tire wear and or a different manufacturer of fuel, same octane.
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Safety Car
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
Reading plugs correctly is one of the dark arts. There aren't that many people who can do it proficiently enough to influence the outcome to a high degree of perfection. I am not one of those select few. In your case, you're not looking for the right signs and there's no way you can eyeball the plugs for anything really useful. Without a good light source and high magnification, you are shooting in the dark. Here's a good tech piece on plug reading: http://www.strappe.com/plugs.html
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
Here is a very good article on reading spark plug coloring. It is important to note that it says you can't read plugs from a car that has been driven back to the pits. The car must be shut down immediately after the run and one or two plugs removed.
So either tow it back or move it off the track and out of the way so you can swap out a couple of plugs.
http://www.dragstuff.com/techarticle...ark-plugs.html
cc
So either tow it back or move it off the track and out of the way so you can swap out a couple of plugs.
http://www.dragstuff.com/techarticle...ark-plugs.html
cc
Thread Starter
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 786
From: Lebanon Township New Jersey
Thanks for the articles guys. They are educational. So the answer to my original question is that timing does affect plug coloring, mostly on the ground strap rather than the porcelain.
