Debate is good.
My personal view is that “silicone [silicon perhaps?] carbide voltage dependent resistors” are comprised mainly of unicorn farts and reptile lubrication, but let’s concentrate on the laws of physics and the results of empirical testing.
The laws of physics dictate that before the spark, the voltage in the ignition secondary circuit is the same up to the plug tip, whether the resistor in the plug is 1 Ohm or 1,000,000 Ohms. It’s an open circuit at the plug tip.
When the voltage in the secondary builds sufficiently to jump the gap, current flows in the secondary circuit. I haven’t the formula at my fingertips, but the laws of physics dictate that the voltage must build to about 2,000 to 2,500 to jump a 0.018 gap. The spark itself has low resistance.
It must be at this point onwards that the resistor in the plug does its high voltage-dependent magic. Before the spark the voltage across the resistor is zero.
The laws of physics dictate that, after the spark starts, the current flowing in the secondary circuit and the voltage at the plug tip are determined by, among other things, the resistance of the resistor in the plug. (The secondary coil has resistance as well.)
The higher the resistance, the lower the current and the greater the voltage drop across the resistor.
And the important bit:
The higher the resistance, the weaker the spark and the shorter the duration of the spark.
There is a very strong correlation between Champion plug resistors that measure very high on a ‘standard’ low voltage Ohmmeter and improvement in engine performance when replaced with a plug that doesn’t measure very high. My personal view is that the resistance measured by a ‘standard’ low voltage Ohmmeter is an analogue for what’s happening at higher voltage. Whatever is the actual cause, the change in performance is a fact.
I’ll bet your bench test doesn’t measure strength and duration. And there are lots of plugs that pass bench tests and fail LOP at altitude.
By the way, an expert in high voltage circuits (he has the patent for the Taser technology) did a test on one of his plugs. The spark jumped
around the resistor in the plug. Imagine how high the voltage had to get to do that, and imagine what that was doing to the coil in the magneto.
And there ain’t no engineer coming anywhere near my fine wire plugs with gapping tools. (No debate.)