Reading spark plugs

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Wally426ci

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any tips?

heres mine. I was just curious how she's performing...

I opted to change to Champion from these Autolites.... Im hearing NGK is pretty good too, Theyre going in my 408 Stroker.. stock heads

:read2:

sparkplug.jpg
 
Hey wally, just a nother suggestion. If you compare heat ranges and lookup a plug for a magnum engine (put 1993, dodge ram, 1500, 5.9L) it will fit your LA head AND have 5/8" wrench instead of the big 13/16...helps with header clearance if you have issues.
 
Need a photo looking down into the plug to see all the color and comotion but from what I can see she's a little on the lean side. Remember it's not just color you're looking at, you're also looking for tiny balls of white=aluminum=piston=$$$$, and yellowish brown scale = coolant and of course black=rich.

Terry
 
You will NOT do better than Autolite when it comes to plugs. I have been using them for close to 25 years, exclusively, in everything I own.

George
 
To me the photo looks like the plug is running lean. Do you have an air/fuel ratio monitor? It's a great tool for knowing what's going on inside your engine. I agree with the other forum members who use Autolite plugs. I tried Split Fire and noticed no gain. I'm going back to Autolites.
 
Lean. You want to see a nice tan color on the center electrode insulator.

Demon's right, plugs can tell more than just A/F ratio.
 
I agree that they look lean. I started using NGK's a few yrs. back just because they were on sale and I have had real good luck with them. I tried Autolite, Champion, Splitfire (which btw is a gimmick because electricity takes the path of least resistance to ground) and NGK's and the NGK's ran stronger and lasted just as long as any of the others in my 93 318 Dakota. I run them in my Cuda now and they seem to do real good but I haven't ran anything else to compare them with.

BTW: Welcome to the board Wally. I think I've seen you on the Cuda-Challenger board haven't I?
 
Thanks everyone, yep I tend to hang on Cuda-Challenger, came here for the 69 Dart im building.... still have to load pics. I'll take more pictures, but i have that frosty white color throughout the insulator. No "balls" of anything building up on the plugs.... Ive gotten a few lean answers so i will mess with that a little, it would be nice to have a monitor. Maybe when i slap on some new headers......
 
Wally426ci said:
Thanks everyone, yep I tend to hang on Cuda-Challenger, came here for the 69 Dart im building.... still have to load pics. I'll take more pictures, but i have that frosty white color throughout the insulator. No "balls" of anything building up on the plugs.... Ive gotten a few lean answers so i will mess with that a little, it would be nice to have a monitor. Maybe when i slap on some new headers......
Click to expand...

Just be careful Wally cuss with the headers installed she'll probably go "way" lean. I'd go one or two sizes higher on the main jets the same time you do the headers.

Terry
 
The black housing on the autolite prevents you from checking the mixture. The porcelain is used to check heat range. Using the porcelain to check mixture is a dumb old mechanics tale! The back pages of every spark plug manufactures master catalog will detail this information out for you. Of course most parts stores don't know what a master catalog is. Autolite racing plugs are not black for that reason. Looks like the heat range is OK.
 
I run ngk and have been very happy with them. The only reason I switched from autolight is the black housing, but now that I have switched I don't think I will ever go back. I have ngks in my race hydroplane all my small blocks, my big block, my /6 and all my other cars/boats/lawnmowers ect...
 
The inside back cover of every Haynes manual I've ever looked at has a realllllllllly nice chart complete with pictures, details and diagnoses about spark plug conditions.

Good luck with the tuning!!!
 
My69Barracuda said:
The porcelain is used to check heat range. Using the porcelain to check mixture is a dumb old mechanics tale! The back pages of every spark plug manufactures master catalog will detail this information out for you. Of course most parts stores don't know what a master catalog is. Autolite racing plugs are not black for that reason. Looks like the heat range is OK.
Click to expand...

Wrong! I may be old, and I may be a mechanic but I'm not dumb. You've got it backwards kid: http://www.4secondsflat.com/Spark_plug_reading.html
 
Ok, well I took her out for a spin yesterday and she ran pretty well. Now i need to mess with the Jet sizes cus it has a little sputter in a low cruise until you step on it. could be a little too much advance as well.... But, at least its looking up!!
 
Sounds like your making progress Wally. The lean stumble is most likely from running so lean. Normally you just make one jet size change per time but as lean as yours look it'll probably take 2 sizes up to get it right. Maybe even 3. Also remember when you change the primary jets you need to change the secondary ones the same amount.
 
Looking at that great article on plugs on the link it looks like your plug is showing a bit too much advance. Says ideal colour change should occur closer to the apex.

Good luck with it.

Cheers
 
Hmmm, that give me conflicting info on plugs then. On the page linked (think for sure it was on this post.... I'll have to check now) the heat range was being estimated for correct by looking at the threads on the plug. The ground electrode was used to look at timing. If the burned point was down from the apex and close to the threads then it was supposed to be too far advanced. If it was at the apex it was supposed to be right on. If it was above the apex then it was supposed to be not advanced enough. Hmmmm.

The ring around the plug is pretty much the same. If black then it is rich at idle. If black and insulator is white all the way then it is rich at idle, but at WOT it is lean and needs a larger jet and to be re adjusted.

Anyone clarify?

I've always read the plugs using the insulator colour for mixture etc. Although can be tougher with today's fuel. Only just trying to see where they indicate for timing so would like to know if I'm on the right track or the picture crackedback posted (thanks for posting by the way even though I'm now in confused mode 8-[8-[ ) ?
 
the v power ngk is a fr4. just so you don't have to ask one of the kids at your auto parts store. platinum is an fr4gp (I go to the subie dealership in less then 2 weeks :) No more shucks!)
 
res1vw21 said:
the v power ngk is a fr4. just so you don't have to ask one of the kids at your auto parts store. platinum is an fr4gp (I go to the subie dealership in less then 2 weeks :) No more shucks!)
Click to expand...

Platinum is GR4GP. :-D And I have a heck of a time finding these in a local parts store.
 
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