Just changing the spark plugs (I have no idea how old they are) all were gapped wrong and they all have the same black soot. A couple has a small glistening of oil as well, not a ton, you have to look hard but im paranoid. Its from a 67 cutlass 330 2 bbl. I was told the soot is from running rich. The reason im changing them is one, I like to tinker, 2 it quits when im idling when warmed up. I already picked up plugs, wires, fuel filter, cap, rotor, points and condenser. She never skips or miss fires but im.asking - do you think I will need to diddle.with that Rochester carb to keep the thing from running rich.
thanks!

 

Do a compression test.

If the plugs were pulled after a short start up without being driven at full temp they will look exactly like they look now. The insufficient gap will contribute to fouling due to a weaker spark.

I'd suggest either cleaning those plugs and gapping them or replacing them. Only the last plug photo shows enough of the plug to make any determination and it looks pretty good with little fouling and virtually no wear on the electrode. If you'd like post pics from that angle of all of the plugs.

Adjust the carb last after all else is in order.

What brand and # are the plugs?

 

Thanks S. bear!
It has been sitting for a few weeks because i had to replace the MC and some brake lines and shoes and cylinders. Fun times lol
All 8 plugs look virtually the same. And manual says gap at .030 these were mostly .019, not a huge difference but I follow the book and have to think its .030 for a reason. And yes the LAST thing I want to do is mess with that carb! Hoping a regular tune up by the book, will help

 

That’s simply not true. Heat range is determined by the distance of the porcelain in the tip, not the gap.
Please don’t post if you don’t know. Thank you.

 

The difference between 0.019" and 0.030" in terms of spark plug gaps is significant.

 

Mark,
Hopefully you seriously don't think I'm going to stop posting because you disagree with what I've posted. One thing I've learned is that I don't know everything and am willing to learn everyday. When I do try to share knowledge with others the most important thing I try to do is show respect to others. Sometime it is mutual sometimes it isn't, your response in my opinion is the latter.

Re-read my post and show me where I said that spark plug gap changes heat range, you'll see that I didn't. If you believe that wider gaps don't produce a hotter/higher voltage spark which would likely keeps plugs cleaner then we disagree.

 

Put your new tune up components in, then give her the ol' Eye-talian tune up- take it out, and give'er hell for 5-10 miles.

 

But it has absolutely NOTHING to do with the heat range of the plug. And in fact a smaller gap could actually INCREASE the intensity of the spark if the larger gap is on the borderline of the coils capacity.

 

holy cow…have you ever got that mixed up. he’s talking about the problems associated with a gap that’s way to small. this has nothing to do with heat range .

two problems happen. there isn’t enough space between the electrode and the ground strap for the mixture. then the spark is weak/small because it’s jumping a smaller gap. because of that, and the smaller amount of mix between the spark path, slow ignition flame/burn leads to incomplete combustion and poor performance, plug fouling and eventual misfire

plugs will look black. it’s you who should give up giving advice. look at what any plug manufacturer says happens with a real small gap.

 

what a load of bs. This is for a stock engine with correct plugs that were gapped way to small

 

Always a good idea!

BTW, what brand spark plugs are they?

 

You obviously don’t do any blower stuff. They run gaps as low as .015 and work just fine. So much for not being able to light the mixture.
A smaller gap works on NA stuff too, its inconsequential. Try it.
Look up Richard Holdener/Junkyard plug gap test.
Picked up 2 hp going from .010 to .100. How much difference do you think it’ll make going from .019 to .035. Probably nothing.
You’ve read too many JC Whitney catalogs.

 

I had no idea how much controversy there was in plugs. Sorry about that. I figure now just run the new plugs to what the manual says for gap size , put in new wires, rotors,points and cap and taker for a spin. I wont ask where to put the dielectric compound on the wire boots, I already saw where everyone has a different opinion on that online! I've already caused enough ****. LOL
also the old plugs were Autolite 83. I put in what my old 1967 manual says. Ac delco 44s.
thanks guys. I like reading the different sides to everyone's take on things.

 

No problem.
Like anything, everyone has an opinion. I make every effort to back up my statements with the facts.
Best of luck to you moving forward.

 

This is tame...ask what oil to use😂🤣😅

 

boosted apps do need closed up gaps, which has nothing to do with what we are talking about here… so why bring up blower applications? other than trying to show off.

and no, way to tight of a gap is not good on a stock application which needs the recommended gap for the reasons and facts I stated.

your insecurities are showing again.

 

From actual research and testing…not a blower application

 

And another from actual research …no boosting 😂😂😂

 

Someone better lock this thread before the resident expert puts his foot in his mouth again..LOCK IT!!!

 

Sure, whatever. Richard Holdener happens to be a very well respected builder and tuner. But of course he’s wrong too.
Have a nice day.

 

I think we can all agree that on a stock or near stock engine following the engine/vehicle manufacturers specification for both heat range and gap at least as baseline is best practice. Should any modification be made to the engine that drastically increases cylinder pressure (dramatic change in compression ratio, camshaft change, installation of a power adder) then experimentation with spark plug gap, orientation and heat range may be helpful.

 

It is something we all seem to have different ideas on plug gap. I set my plug gap at .045"+ on Olds V8's. The only time saw issues, even with the .080" gap was on a cold damp morning, the reliable 307 would not start. The plugs were .100"! While that .015" gap is pretty tight and should be opened up, especially with some foiling, gunk could easily fill that tiny gap. But heat range definitely effects plug cleaning and pinging, a big deal on high compression engines.