Today, after inadvertently stalling my car, I proceeded to then inadvertently drive the car with the switch on "battery" for a while. I quickly noticed something seemed different from the typical engine noise I am used to hearing. I looked down and realized that I forgot to switch back over to "magneto", and as soon as I did, the familiar stopwatch like "tick...tick....tick....tick" sound of the coils returned. Puzzled, I switched back to "battery", and sure enough the discrete coil ticks went silent. I have no doubt that the coils were still functioning as the car continued to run great.
I always switch right over to magneto after starting the car on battery, so I can see why I never picked up on this before.
Is this one of the characteristics of a normally functioning ignition system? Or is it indicative of something else?
The magneto does not provide a continuous flow of electricity, you could say it come in drips. Ok at speed really fast drips.
If the magneto's good they will be spurts.
I have also noticed the difference that Dan talks about. From a technical point, surely the points perform less 'work' while running on mag and should last longer?
As John Regan pointed out that is normal.
Here is a link to an article Steve Coniff and I wrote several years ago in an attempt to simply explain how the Model T Ford ignition system actually works. It explains the difference when running on battery and magneto.
The Model T Ford Ignition System and Spark Timing
Thanks all and Ron, I look forward to reading that article. It is always helpful to know the why's and not just the way that it is.