Coil interchangeability?

[Vzike]

yes I just learned this lesson taking apart my distributor for maintenance and discovered the dioxins chem as Rick explained.



before:


after cleaning

Dioxins are a class of chemicals. The main ingredient in old dielctric oils, the thing that made them electrically resistant as well as thermally stable, was PCB, aka polychlorinated biphenyl. All dioxins are PCBs, but not all PCBs are dioxin. Dioxin is an unwanted by-product of PCB productions. Many, but not all coils can contain PCB oils, and that is only for coils made before 1979. And it was only for coils that did not use Shell dielectric oils, at the time marketed under the names of Diala, and Diala AX. None of Shell's dielectric oils have EVER contained PCBs. Shell produced an oil with all the necessary protections against electrical conductivity as well as thermal stability without using PCB oils. That was always one of their sales points.

If you have an old coil that has failed, use rubber gloves to clean it up. It is not like some sort of nerve agent like VX or Sarin. It is not instant death. There are still millions of electrical transformers, the type you see at every substation, and on every pole, still in use. But it is still something to not get directly on your skin. While it's toxicity is low, it's negative effects are cumulative.

Now for the supposed use of an internal resistor on the Chinese "chrome coils": I suspect it is true, and that it is an internally variable resistor, which would explain the lack of a difference in output with 12 vs. 24 volt input. With an internally variable resistor, the resistance increases as voltage increases.

This would explain a lot. Namely that the Chinese manufacturer knew that as voltage increased, so would heat, and that would shorten the life of a product they knew to not be made to the same quality standards as U.S. companies such as Prestolite.

I've been rebuilding Distributors, and the black "goop" on that coil (pictured above) is likely not from the coil. It is more likely from the melted potting material on the upside down potted Prestolite ignition module. I find that sticky stuff in about half of the coils I rebuild. It is a PIA to clean out. I just sold all my NOS Prestolite coils to someone, loudly giving the disclaimer that they are prone to melting down.

[rickf]

Coils or modules? The ignition module is in a different cavity in the distributor. I just don't see all of the potting material getting from the module over into the coil cavity. Either way, I would not take chances with it.

[Hell on Wheels]

I cleaned them up and it ran fine with a little oscillating but eventually just replaced the coil and module

[Vzike]

Both cavities are open to each other. The angle that the distributer sits on, lets the potting material flow to the coil side. I've never seen that happen in a Swiss control distributer.

[raymond]

I had a coil essentially "explode" a few years ago, and it leaked that crap everywhere. And I run Swiss Control.

[Lou]

yes I just learned this lesson taking apart my distributor for maintenance and discovered the dioxins chem as Rick explained.



before:


after cleaning

Dioxins are a class of chemicals. The main ingredient in old dielctric oils, the thing that made them electrically resistant as well as thermally stable, was PCB, aka polychlorinated biphenyl. All dioxins are PCBs, but not all PCBs are dioxin. Dioxin is an unwanted by-product of PCB productions. Many, but not all coils can contain PCB oils, and that is only for coils made before 1979. And it was only for coils that did not use Shell dielectric oils, at the time marketed under the names of Diala, and Diala AX. None of Shell's dielectric oils have EVER contained PCBs. Shell produced an oil with all the necessary protections against electrical conductivity as well as thermal stability without using PCB oils. That was always one of their sales points.

If you have an old coil that has failed, use rubber gloves to clean it up. It is not like some sort of nerve agent like VX or Sarin. It is not instant death. There are still millions of electrical transformers, the type you see at every substation, and on every pole, still in use. But it is still something to not get directly on your skin. While it's toxicity is low, it's negative effects are cumulative.

Now for the supposed use of an internal resistor on the Chinese "chrome coils": I suspect it is true, and that it is an internally variable resistor, which would explain the lack of a difference in output with 12 vs. 24 volt input. With an internally variable resistor, the resistance increases as voltage increases.

This would explain a lot. Namely that the Chinese manufacturer knew that as voltage increased, so would heat, and that would shorten the life of a product they knew to not be made to the same quality standards as U.S. companies such as Prestolite.

I've been rebuilding Distributors, and the black "goop" on that coil (pictured above) is likely not from the coil. It is more likely from the melted potting material on the upside down potted Prestolite ignition module. I find that sticky stuff in about half of the coils I rebuild. It is a PIA to clean out. I just sold all my NOS Prestolite coils to someone, loudly giving the disclaimer that they are prone to melting down.

Hi Vin,
That was me that purchased the prestolite Ignition modules. I agree that mess appears to be from the Ignition Modules, not the coil.

[rupert's]

I have come across these m38A1 coils. https://www.debellajeepparts.com/M38_EL ... ATALOG.htm
I don't know what I'm talking about and ignorance is daring ...

From my point of view they seem very similar to the mutt, maybe they can be worth it?

[Mark]

It said not to be used with electronic ignition, just with points.I do not understand that at all?

[rickf]

Louie did a big write up on those new coils. He explained the problem with using them with electronic ignitions. I will find the write up and link it here when I get a chance.

[Lou]

Louie did a big write up on those new coils. He explained the problem with using them with electronic ignitions. I will find the write up and link it here when I get a chance.

Here you go folks.......
https://www.youtube.com/watch?v=4pSG_X1 ... Yo&index=4

The main issue with the reproduction coils is the primary resistance is double what it is suppose to be. This causes a large inductive "kickback" when the electronic ignition module opens the circuit to fire the coil. This voltage spike eventually causes the electronic ignition module to short out and takes out the coil with it.

This is why many who have used the reproduction coils with the electronic ignition module wind up with both a blown ignition module AND coil!

[rickf]

Louie, could that kickback be controlled with diodes?

[Mark]

Thanks Louie

[rickf]

Thank Louie, he was the one that did all the work. And brought the link up too

[Lou]

Louie, could that kickback be controlled with diodes?

I am sure that the electronic ignition modules have some type of diode in them already to absorb the spikes. In the old TV days we called them damper diodes. Most likely the one in the module is not designed heavy enough for the kickback voltage and current. Still want to get my hands on a defective prestolite ignition module to reverse engineer. Would love to have a schematic as well.

[rickf]

I have a brand new Prestolite that the potting melted out of in the bag. And a couple bad coils.