Coil autopsy

[Refit1701]

I took all precautions against flying danger oil when attacking this military coil. I drilled a hole into the bottom which eventually was nearly 3 inches deep and began to suspect there was no oil. I drilled into the top and met copper. Throwing caution to the wind, I cut the case apart and it fell open, revealing solid black stuff. I probably can get down to the copper (which is visible in the cuts) but am not sure about the black stuff. I used gloves, face shield plus goggles, etc.

I think there was a resistor on the bottom.

Not what I thought, for sure,

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[Refit1701]

I wonder if the chinese coil has oil in it?

[rickf]

That is interesting, The resistor would make sense since the old coils had a resistor that sat under the coil. They simply incorporated into the coil. I know the Chinese ones have oil in them because when they go they leak all over the damn place! And I would be willing to bet that oil is certainly not regulated by any environmental agency!

[Lou]

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Interesting! Thanks for the photos, would like to know the information on the label. My bad coil looks like yours but has oil in it as it is leaking out the bottom. Yes that is a resistor on the bottom. Did the bottom of your coil have a sand like texture on the bottom? That is where my coil was leaking from. Maybe your coil had oil in it and it leaked out and that is why it went bad. Did not expect there to be potting material on the coil, will make checking the windings almost impossible.

It may be possible that some builders of coils used potting instead of oil to insulate the windings. Only way we will all know is for us all to open our bad coils and compare manufacturers and contract numbers.

Will post a photo of my coil label soon to compare.

[lpcoating]

I was looking through my 151 parts stash and came across this distributor. I'm pretty sure this is out of my '68 A1. The odometer has 7,800 ish miles on it and when tearing engine apart, it appeared to be very low milage. Well, the internals of this bad boy look pretty darn good to me. I'll take this as my weekend personal victory!

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Guy