Automotive grounding and spark plugs

[Elektrishun]

Reading through the trailer wiring thread got me thinking about automotive grounding and some older vehicles that were designed with a "positive ground".

That led to more thinking and reading about spark plugs and electron flow. This gentleman put out a good video which touches on all of that. You can watch it all or to get to the meat of what my question will be by jumping to roughly 8:30 of the video (link below):

Why positive ground was used on old cars, trucks and tractors

The part that I am mainly focused on is when he states that with regards to the spark plug "the center electrode is negative and the ground tang is positive".

I am not trying to pick on that comment because I believe the guy in the video is a lot smarter than I am and knows what he is talking about.

But to help make it clear in my mind wouldn't it be more accurate to state "the ground tang becomes relatively positive due to the momentary high negative voltage of the center electrode"?

I realize it gets more complex regarding polarity with a wasted spark ignition system but if we were to stick with what the guy in the video is talking about does his comment sound a little misleading?

Maybe it's just my interpretation. Still, it makes more sense to me thinking of it my way when electrons supposedly flow from negative to positive (never seen electrons moving myself so I can only assume science is correct🙂). Which means the electrons are moving from the spark plug's center electrode to the ground tang which is connected to the engine block which is connected to the negative side of the battery.

 

[slow-poke]

I'm an EE and I very very rarely think about electron flow.

I do think about polarity and relative grounds all the time.

In the ignition example, the high voltage is a result of the collapsing field of the coil (negative polarity) into an open circuit (until the voltage gets high enough to ionize the mixture in the gap). Once the flash starts, the voltage required to maintain the arc becomes much lower.

Back in the day when MSD became popular, they had little demonstration units in all the speed shops. Push the button and watch the single spark from the conventional ignition switch and then flip the switch to MSD mode and watch the sustained bright arc from the MSD ignition. Fantastic marketing, everyone bought one, on sale for $65.

 

[Elektrishun]

Backward hat dude: "8 grand is cool but boost is better."
Forward hat dude: "That's a true fact right there."

I could listen to these guys talk all day.