So, playing with my toys today, I found this…. It’s the only one that looks this way, the others are clean as a whistle. It goes to #2 if that matters.
I believe that's mostly caused by a weak plug wire which causes a higher than normal voltage rise from coil. Causes corona, you know the glow at night on old spark plug wires. Possibly aggravated by moisture trapped inside boot. Be sure plug isn't cracked. A small amount isn't harmful but if bad enough will eat away at terminal. Clean with softish wire brush and add a little dielectric grease. Cap terminal probably needs cleaned as well, be sure it isn't cracked. Before making a final determination, check the wire's resistance. Std resistance wire should be around 7500-10000 ohms per foot.
I figure any corrosion might cause or be caused by increased heat and resistance in the connections. I’ll check the resistance in the plug wire, and inspect the plug as well. I did inspect all the other wire ends, and they had some dielectric grease in them for sure. I did spread the connectors out a bit with some pliers, because they seemed to pop in and out very easily. Now they seem to click into the terminals and feel pretty snug. The car sat for inside for ten years after the motor and trans were done and stuffed into the car. I’m finding all sorts of little things that need attention. But I’m finding them by driving it! It’s a recessed style cap. Most of the duraspark caps im seeing have the exposed posts. Is that something I should switch to?
Duraspark I used std cap, the II system specced wider plug gaps & used the large cap with male terminals. I'm of the opinion if plugs are fairly fresh, doesn't make much difference. Large caps reduced cross fire when plugs had 50/ 60K miles on them. Those also introduced when mfgr thought .060-.080 plug gap was a good idea. I have large cap on Comet, points dist triggers a '80s TFI module. Fairlane has std cap with points(in other words, day one). Cobra has a Pertronix unit triggering a Crane Hi-6. Also std cap, Blaster coil(painted black) and Pertronix 7mm Flamethrower, spiral core wires. Plug gap on Comet & Cobra at .045.
