Spark plugs. Why is it so hard?

Bewy said

448Scamp.

I knew I had seen advertisements for NGK Copper splugs from my motorcycling days.
Went through some old magazines & this ad was on page 11 of Cycle Guide magazine, July 1969. 'Exclusive Hear-of-Copper guarantees the widest heat range. Cuts tip erosion & fouling...'

The Jerry Reeves link says towards the end. 'Lets look at some facts that support fine wire plugs are a good choice for a performance engine..'

Click to expand...

Yes sir, I read that. And the only thing I read that was performance oriented was that a fine wire plug takes less voltage to ionize the gap. I don’t think anyone here would argue that. I don’t think anyone here would argue that a precious metal center electrode will last longer than a copper electrode plug. I do know that several ignition engineers I’ve spoken with all have a different opinion of how the ionization of the gap occurs. And that’s an issue because depending on which understanding you follow will directly impact the choice of spark plug. Also in the conversation must be the fact that current OE ignition systems are miles ahead of what most here on a forum like this use. These OE ignitions will fire less than optimal chamber conditions (either rich or lean of stoich and even at that it’s only stoich to about 5% rich for best chamber conditions near the plug) much better than say the Chrysler ignition or the many knockoffs of that concept or even the much ballyhooed HEI. In the case of running these less efficient and powerful ignition systems, a precious metal center electrode can cause an undetectable misfire, which in turn causes an O2 sensor to read rich when the engine isn’t really rich at all. In the end when all the chatter has fallen away, it remains if the ignition is up to snuff then the only benefit to a precious metal center wire is its working life span.