Spark plug reading?

[73Scamp318]

I've changed out the plugs in my Duster and am trying my hand at reading them. From what I can tell, the initial and total timing are about right, it's pig rich at idle, lean at WOT, and the heat range is about where it should be. Here are the plugs in order from 1 through 8 from my 360 with Edel heads and standard Mopar ignition, don't mind the oil on the threads from valve cover leaks that have since been fixed. Am I close or way off?

View attachment 027.jpg

View attachment 028.jpg

View attachment 029.jpg

View attachment 030.jpg

View attachment 031.jpg

View attachment 032.jpg

View attachment 033.jpg

View attachment 034.jpg

 

[bOb shingler]

looks to be oil fouled, can use more timing and you used them far to long. you also might want to consider a msd unit. you could get it to idle leaner if you opened the idle air bleeds up a few thou.

 

[vtmopar]

What brand of plugs are you using?
Those look like champions
I switched to accells last year and noticed a difference in plug life over champions
Always had good luck with champions but seemed the accells performed better and longer

 

[moper]

I find Autolites seem to last the best, and they are easier to read than Champions for me. The "best choice" in terms of reading are the NGK Race plugs. A little more money, but I like tham in something that has to make power. What I see, is you need to replace them after you warm up the engine, then drive it, and then look at them. They've got too much carbon and soot on the rings to be of much use.

 

[pettybludart]

I also run the Auto-Lites race plugs in my Eddy heads.It looks like some of your gaps are off?I tried the NGK,s and my car ran slower.:wack:

 

[JoeDust451]

NGKs are the easiest to read, Autolites not so much. Seeing the glaze on the porcelin those plugs overheated & are junk, trash them & go 1 step colder.

 

[Guitar Jones]

NGKs are the easiest to read, Autolites not so much. Seeing the glaze on the porcelin those plugs overheated & are junk, trash them & go 1 step colder.

I agree, I see some gray/silver flecs on them and if that's the case it's been detonating. You may need to go more than one step colder or use better fuel.

I'm using NGK race plugs in mine but have also used Bosch and Champion with good results. What I did find is the heat range needs to be correct. Use the coldest plug you can and have it still run well. I would keep going colder one step at a time until it doesn't run well anymore.

The other advice in this thread is good, such as an MSD and leaning out the idle circuit a little.

 

[73Scamp318]

The plugs are champion rc12yc and they have about 6 months of use on them. I swapped them out for a new set I already had on hand.

They may have some oil on them, they're the same plugs that I used for break-in and I put less than 2000 miles on the car this year. I have a msd 6al that will be going in while the car is in hibernation for the winter.

I didn't see any gray or silver flecks on them when I was eyeballing them...it might be from the flash on the camera, but I'll recheck.

After I swapped them out, I started the car up to get the new antifreeze I put in cycled through the engine. After idling long enough to get it warmed up, I decided to pull some of the plugs and found that the front four (1,2,3,4) are completely black and the rear four (5,6,7,8 ) still look new. It looks like the idle circuit on the secondaries isn't working and I'm going to pull the holley for a rebuild before next season.