My 422 smallblock build
The total timing is all in at 2200. Distributor has 2 of the light springs in it but I have other springs coming from Mancini to slow the curve down. Probably shoot for around all in at 3000 and go from there. Currently has a 6.5 power valve but I might try a 10.5. Its got a lean surge when the throttle blades are almost closed. Feels like “fish biting” when going down a slight grade.
That’s why the plug looks like it does. You have too much timing around and below peak torque and maybe just enough at peak power or you could be a little retarded at peak power.
One of the things to look at when checking your plugs is to compare the sharp edges of the ground strap and center wire of a new plug to what you see on a used plug.
When you see the sharp edges getting rolled over like that (or worse yet is when the side of the center wire is melted) the plug has too much heat at relatively low power and load.
If it’s getting after the ground wire that’s usually too much heat in the plug and high power and load.
There is a thing called “spark mark” (I suppose there is a text book name of it but I can’t recall it right now) and it looks like tiny little pock marks on the top of the center wire.
That is a good thing as that’s an indicator the ignition is nice and hot. I know at one time and it’s probably is still so that part of what helped get the spark started was the center wire would release molecules at ignition and that made firing the plug easier.
The issue was and still is how long the plugs last.
To that end you had three major spark plugs on the market when I came along. Champion, NGK and Autolite.
I put them in that order because Champion used the softest material in the center wire. NGK is in the middle and Autolite is the hardest material.
Not trying to go full AJ but this is the first time I’ve seen a good picture of a plug like yours on FABO so I think an explanation might help some read plugs not better but with more depth or whatever.
At any rate, the Champions to this day are still the softest and will need to be replaced sooner than the other two. Of course the Autolites will go longer than the other two.
If you are ignition deficient the Champions can help with random miss fires and such but they don’t last as long.
And because people generally don’t do tune ups frequently enough they lost performance by leaving the Champions in too long. Of course switching to an autolite made them last longer but with a weak ignition you can lose performance. And the emissions can go up.
And to finally wind this up, with the new stuff so crowded and cramped and because most people don’t check their oil and change it frequently enough just like the plugs rare earth metal plugs go in.
That stuff is harder than the hubs of hell. That’s why they can go 100k plus miles and not really lose much.
For what we do those plugs are a waste of money. And they are harder to fire. If you run points it’s noticeable. Even the much ballyhooed HEI is not enough energy to fire the plugs with rare earth metal construction.
Do guys do it? Yes. Will I do it? Nope.
Edit: I forgot to mention that the rare earth metal plugs use a very fine center wire to help get things going. A fatter rare earth metal plug would be much harder to initiate a spark. So they use a fine wire center electrode.
And fine wire plugs are not new. We used them in 1972 on dirt bike stuff. Before that even because one of the first things my dad did was switch to fine wire plugs when he bought his first two stoke which was 1970 I think.
They were fine wire but not rare earth metal and it for sure helped with the weak ignitions back then.