Spark plug timing marks

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512Stroker

512Stroker

We are all here because we are not all there.
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OK you engine Guru's
Does anyone have a clear image they can post of what the timing mark is suppose to look like on the plug electrode?
I have tried to read mine and came up empty handed, may not have enough run time on the plugs?
 
The timing Mark should be in the curve of the ground wire for race gas. Pump gas and alcohol based fuels can run the timing Mark around the corner a bit.

I'll look and see if I can find some good pictures.
 
yellow rose said:
The timing Mark should be in the curve of the ground wire for race gas. Pump gas and alcohol based fuels can run the timing Mark around the corner a bit.

I'll look and see if I can find some good pictures.
Click to expand...
Are you still at your mom's house?
 
512Stroker said:
OK you engine Guru's
Does anyone have a clear image they can post of what the timing mark is suppose to look like on the plug electrode?
I have tried to read mine and came up empty handed, may not have enough run time on the plugs?
Click to expand...
all joking aside can you post a picture of what you're looking at it sounds interesting...
 
j par said:
Are you still at your mom's house?
Click to expand...


Yep. Was going home tomorrow but OHSU is dragging their feet and I don't want to leave until I meet that heart Doctor. Been waiting to hear from that joker for over a week. Called this morning and kicked some gals ear. Hopefully I hear back today.
 
j par said:
all joking aside can you post a picture of what you're looking at it sounds interesting...
Click to expand...
I tried to post a picture but it was to crappy to make any sense of.
Cheap *** phone makes a poor camera at that close of range.
 
j par said:
Well the term timing mark on a spark plug is new to me...
Click to expand...
A lot can be learned by proper reading of a spark plug.
The timing marks are found on the ground strap.
Great info from Dubob in his reply to this thread
 
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If you are running vacuum advance the mark will be lower on the strap, more timing. Sometimes it is easier to read the inside portion.
 
Look for faint white lines at each side of bend on plug tang about an 1/8th apart.

The one towards the electrode are initial...and the one nearest base ring are total/full advance. the closer those two are, the shorter the advance rate is...for instance, 22 initial and 32 will be closer than 12 initial and 36.. which would be wider gap with the initial mark further out on the tang near electrode.
 
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MOPAROFFICIAL said:
Look for faint white lines at each side of bend on plug tang about an 1/8th apart.

The one towards the electrode are initial...and the one nearest base ring are total/full advance. the closer those two are, the shorter the advance rate is...for instance, 22 initial and 32 will be closer than 12 initial and 36.. which would be wider gap with the initial mark further out on the tang near electrode.
Click to expand...
Kind of like a verification of what your timing light is telling you?
 
MOPAROFFICIAL said:
Kinda like letting you know if it's set where that particular motor likes it.
Click to expand...


That's why setting your timing at a given number and not checking the plugs is a waste of time. If the timing light says 35 (for example) and the timing Mark is above the corner, it wants more timing, regardless of what the light is saying.
 
512Stroker said:
OK you engine Guru's
Does anyone have a clear image they can post of what the timing mark is suppose to look like on the plug?
I have tried to read mine and came up empty handed, may not have enough run time on the plugs?
Click to expand...
Well after all this good info I went back out and looked at the plugs again.
It appears that the timing mark is 3/4 up from the threads before the bend. Never did see an initial timing mark on the flat part of the ground strap.
Timing is currently set at 16* initial, 36* all in at 3200
I am running a vacuum advance that kicks up the total timing to 44* all in.
Healthy ported iron head 340, engine runs well at these settings.
I think I will leave it where it's at and check it again after a couple hundred more miles.
Thanks for all the help
 
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For some visual inspiration to the thread I went ahead and pulled my number two plug. As you can see I run a cold plug. The car was probably running about 190° the whole time, give or take. 11 to 1 compression. Timing, initial 22-24 and all in at 35-36. Two parts 92 non-ethanol one part 110 race fuel. The plugs have been in for a while and the most recent drove to the track took some passes took the freeway and a recent ride to a friend's house. I've been seeing a lot of 13 in my AF gage. Some 12 at wide open throttle and some 14 at idle, but don't quote me because it moves a lot. ..
IMG_20190604_135354.jpg
looks a little dark to me...
IMG_20190604_135027.jpg
IMG_20190604_135056.jpg
 
A good sparkplug reader: SPARK PLUG READING AS I SEE IT.
 

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j par said:
For some visual inspiration to the thread I went ahead and pulled my number two plug. As you can see I run a cold plug. The car was probably running about 190° the whole time, give or take. 11 to 1 compression. Timing, initial 22-24 and all in at 35-36. Two parts 92 non-ethanol one part 110 race fuel. The plugs have been in for a while and the most recent drove to the track took some passes took the freeway and a recent ride to a friend's house. I've been seeing a lot of 13 in my AF gage. Some 12 at wide open throttle and some 14 at idle, but don't quote me because it moves a lot. ..View attachment 1715344846 looks a little dark to me...
View attachment 1715344849 View attachment 1715344850
Click to expand...
My concern would be with the dark spots on the insulator.
That is a sign of detonation.
 
j par said:
For some visual inspiration to the thread I went ahead and pulled my number two plug. As you can see I run a cold plug. The car was probably running about 190° the whole time, give or take. 11 to 1 compression. Timing, initial 22-24 and all in at 35-36. Two parts 92 non-ethanol one part 110 race fuel. The plugs have been in for a while and the most recent drove to the track took some passes took the freeway and a recent ride to a friend's house. I've been seeing a lot of 13 in my AF gage. Some 12 at wide open throttle and some 14 at idle, but don't quote me because it moves a lot. ..View attachment 1715344846 looks a little dark to me...
View attachment 1715344849 View attachment 1715344850
Click to expand...


Look at the rolled edges. That is too hot, and you are cooling the plug with fuel. You need to get a cooler plug in there and then start taking fuel out.

It's defiantly fat at idle and probably cruise. With the shell on its hard to to see WOT but I'm betting it's fat there too.

Always watch the sharp edges. When they start getting round you are too hot.


Edit: I forgot to mention you are showing heat 3 threads down on the shell. YIKES. That's plenty plenty hot. I don't like to go past 1 thread on a champion, or two threads on an NGK.
 
512Stroker said:
My concern would be with the dark spots on the insulator.
That is a sign of detonation.
Click to expand...
I was getting a little detonation at shut off when I stopped using a little bit of race gas. So, a little 110 and shuts off fine. The timing seems spot on. Never any pinging or valve clatter...
 
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