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General What do these plugs tell you.

1cleangsx

Proven Member
710
584
Sep 28, 2013
Cheyenne, Wyoming
Hey guys, I just threw in a new set of NGK br8es plugs, which I’ve ran in the past, replacing br8 iridium’s. These have maybe a few miles and 4 WOT pulls or so. AFR’s we’re 11:6-11:4 at WOT on a 6266 at 26 psi on 72% ethanol. 9:1 motor, from what I’ve read and gathered a full white strap could be too little timing? Maybe too cold of a plug? I have some br7es plugs I can throw in, timing up top is 13 degrees. I appreciate any opinion/help!
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1990TSIAWDTALON

Moderator
9,408
5,232
Nov 14, 2013
Independence, Kansas
They look ok to me too, although I am not a perfect plug reader, I have been reading them on my sons 400 SBC to see if we can add timing and we need to. Your plugs look like they are spot on for timing as the ground strap is the same color from its end to the bend.
I hope we can have another opinion so you are getting good info.
 

1990TSIAWDTALON

Moderator
9,408
5,232
Nov 14, 2013
Independence, Kansas
I run the non-projected tip Copper NGK 8's and mine are necked down to .018 too Jeremy.
 

1cleangsx

Proven Member
710
584
Sep 28, 2013
Cheyenne, Wyoming
So far .023 works for 26 psi:D

Now that I think about it Marty I think I’m having an ignition issue and I wonder if it’s the plug gap or my coil pack, but sometimes at low rpm from a stop there’s like a flutter as I’m releasing the clutch, I have to rev it up a little or else it doesn’t want to accelerate. It reminds me of when my alternator died and I barely made it back to the house, on 7-8 volts that’s what the ignition sounded like:idontknow:
 

danl

Proven Member
690
99
Apr 8, 2002
Severn, Maryland

On the attached image, do you see a blue line where I added arrows?

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1990TSIAWDTALON

Moderator
9,408
5,232
Nov 14, 2013
Independence, Kansas
It won't kill it to run a tighter gap but it "usually" gives you issues under high boost (when I started getting over 35lbs up to 44) Jeremy. It would just be an experiment.
GOOD EYES DANI.
I couldn't see the mark you pointed out on all 4. Good to have other people looking at these. Now, do you think that he "could" run more timing? I can't see down in the porcelain for pepper mark's but just like others opinions for sure.
 

bastarddsm

Proven Member
5,448
1,279
Aug 26, 2003
Mendota, Illinois
They are probably about 10* retarded. Don't do that unless you have a crank trigger though. Sand the cad plating off and hit em again. Line will show up better.

Also remember that reading plugs is no more than "the motor ran really good, so we pulled the plugs out and they looked like this"

They honestly look like the plugs a little cold to me, but IDK I'm on 9's and i think it's perfect on mine at a 8.5:1 motor at 28-29psi.
 

danl

Proven Member
690
99
Apr 8, 2002
Severn, Maryland
So with the line being above the bend the timing is on the high side?
Above the bend is not enough timing, below the bend (closer to the threads) is too much. Right at the bend is about where you want to be.

NGK puts a coating on their plugs. That coating turns to grey and makes it hard to see the blue line. I can't tell from the pictures if there is a blue band under that grey. Some people will sand the coating off and do a pull so that they can see the blue better.


Another good one: https://www.crankshaftcoalition.com/wiki/Reading_spark_plugs#Example_plug
 

bastarddsm

Proven Member
5,448
1,279
Aug 26, 2003
Mendota, Illinois
remember, non projected plugs and tight gaps are the same as retarding timing. a little pepper isn't terrible at some boost levels, but could be catostrophic at others.
 

habitatguy187

Proven Member
3,464
160
Aug 20, 2008
Indianapolis, Indiana
remember, non projected plugs and tight gaps are the same as retarding timing. a little pepper isn't terrible at some boost levels, but could be catostrophic at others.
Same as retarding timing.... Will you elaborate on that please?
 

1cleangsx

Proven Member
710
584
Sep 28, 2013
Cheyenne, Wyoming
I tried Vegas to load the log but couldn’t figure it out on the laptop LOL, it’s been a while but I’ll keep trying, I’d love the feed back:thumb:
 

1990TSIAWDTALON

Moderator
9,408
5,232
Nov 14, 2013
Independence, Kansas
Load the log as a "photo" Jeremy.
 

danl

Proven Member
690
99
Apr 8, 2002
Severn, Maryland
I’ve also heard this but don’t understand, might also explain the line on my ground strap indicating “too little” timing:coy:
The heat range of the plug is a measure of how much heat the plug retains between firing events. So a hotter plug holds more heat between combustion cycles and a colder plug, less. If the plug is staying colder on average, then the ground strap will show the blue line at different points depending on the plug heat range.

Another thing that affects this is how much time you have on your pull. A third gear pull is a shorter duration than a full quarter mile pass. If you have an auto car, then its even worse because you aren't lifting between shifts. I run less timing overall on an auto car due to this.

This is how I do it, I'm probably wrong because I am self taught so YMMV. I pick my plug heat range by power level. Stock plugs for stock power, BR7ES for up to 100 more than stock. 8ES for 300-500whp cars. 9ES for 500+. You should see the last 2 threads of the plug to have some color in them.

Tune on the dyno to build a timing curve that gives you max torque at each RPM and load interval. The dyno is a tool that helps you build your curve. Throw a fresh plug into cyl #2 and do a pull. Take note of the blue line and remember this. Back off global timing a couple degrees.

Take it to the track and do a 1/8 mile pass on fresh plugs. Look at the timing mark, do you have enough timing mark left in it to do a full 1/4 pass? Do a full 1/4 pass, look at timing mark on the plug. Add in 1 degree globally at a time to get back to where your timing mark was on the dyno. You should see MPH pick up each degree you add but you may not achieve the same timing as you had on the dyno. Stop if timing mark goes too far past the bend or if MPH does not pick up. You have now found peak timing.

When you put it back on the street take 2 degrees out of the timing that you had at the track. This is your safety margin.

If the timing marks look different on the plugs you have a fuel or air distribution issue that needs accounting for. I think I see something like that on your right most plug in the pictures but I can't quite make it out in the photos.
 

1cleangsx

Proven Member
710
584
Sep 28, 2013
Cheyenne, Wyoming
here's a log from earlier tonight, the car feels AWESOME at WOT. I'll pull the plugs tomorrow and check them. Ive added 2 degrees across the board. This cars gonna scare the $h!t out of me at 35-40lbs LOL..
 

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1cleangsx

Proven Member
710
584
Sep 28, 2013
Cheyenne, Wyoming
And the car still has that same ignition flutter at low rpm when engaging the clutch, i have to rev it a little when releasing the clutch, ive boost leak tested it several times veryfying zero leaks, the only air leak i have is at the hallman pro mbc which i believe is normal right? Anyways i appreciate any criticism/advice, thanks guys!
 
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1990TSIAWDTALON

Moderator
9,408
5,232
Nov 14, 2013
Independence, Kansas
here's a log from earlier tonight, the car feels AWESOME at WOT. I'll pull the plugs tomorrow and check them. Ive added 2 degrees across the board. This cars gonna scare the $h!t out of me at 35-40lbs LOL..
You'll get used to it Jeremy, I did and now I'm "spoiled" ROFL
40 lbs is hella fun, just keep it between the ditches!!! :thumb:
 
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