MTFCA Forum

If indidual magneto coils test good but have bad wrappings, has anyone rewrapped 16 of them and made up a new magneto coils ring without rewinding them and putting new insulating material between the windings?

I doubt it. If you get the ring out of the car and the coils off, you're into a pretty big job. Might as well do it all the way.

Yes you can do it. But you have a couple of problems.
First is you will need to soak the whole mag coil for a few weeks to get the oil out it. If you don’t you have an oily mess.
Next is cleaning up the ring, cutting new insulation for the ring.
Last you will need to take it to a local motor shop to have the whole thing dipped and baked so the coils will stay on the ring.

I have two that I wound on two of my cars and they work fine. I used the book "Electical System". I cut the insulators from Amphanol which I got from an electrical supply store, and wrapped with fiberglass tape. I painted with boat varnish from the marina. Didn't need to bake anything. I also made another and donated it to an auction at the local club. Have not heard anything was wrong with it and it was over 20 years ago.
Norm

I’m glad you can buy a rebuilt coil ring. Could I have rewound one? Yes and it’s time consuming and if you want to do it that’s great. There’s lots of information on how to do it.

I bought a rewound for each of my 3 cars. They still work fine after several years.
For any rebuild of a Model T engine the magneto coil is a BIG must do to get the electrical system right.
For a good dependable Model T a good or new radiator core at least and a good rebuilt magneto coil ring is a bottom line must.

I have done them years ago, soaked them in draino to clean the copper, it was time consuming and decided after to just buy them done they are to deep in the engine to mess up.

One very important thing about rebuilding an engine or installing a coil ring is to get the funnel for the inside oil line aligned correctly and not bent. Many years I bought an engine transmission from the swap meet. It had been built by a good mechanic and machinist in the area. The first time I drove the car after the work was done, I was running on magneto when all of a sudden the engine quit. I switched to battery and it ran fine, but with less power and speed. I drove it for 10 years and then needed to pull the engine to do some work and I found the funnel from the oil line in the bottom of the crankcase. I did have an auxiliary oil line from the magneto plug down to the front of the engine. The winding on the magneto ring was cut when that happened years before. That was when I installed one of the coil rings I had rewound. Now I have changed from one of the slowest cars on tours to one of the faster ones. I can keep right up with the others. I
If I were in your position, I would either rewind the coil ring or buy one already rewound, because it is one of the hardest to get to parts and the better condition it is when installed, the longer it will work.
Norm
Norm