Plastic coils

[Don ellis]

Is there any use for these before I part them out? I figure I can at least get the hardware and tar.

[Humblej]

I use plastic coils, have had them for over 50 years. They do not swell in the coil box like wood. Why do you want to part them out?

[Don ellis]

I’ve always heard bad things about them

[Humblej]

I will trade you wood for plastic, if you are intetested send me a pm.

[Kerry]

I have 5 T's and all run coils, one has 4 plastic ones in it for several years, a stock 27 and a long distance tourer. The only issue I've had with one coil is it broke one side of the points, an easy fix.

[John kuehn]

Just because you heard the plastic coils aren’t good isn’t always the case. If they are still working use them till they won’t work. I also heard they weren’t any good. Never used them but others have with no issues.

[Wayne Sheldon]

Personally, I hate those things. But why I hate those things may not be what you think it is.
The truth is, good ones are good. Bad ones are bad. The real problem is that it is tough to tell the good ones from the bad ones. They have been making "those" plastic case coils at least since 1965, before I was old enough to get a driver's license. When I was working on my first model T, before Ron P and a couple other people were smart enough to figure out the how and why of the model T ignition system, original wooden coils were a crap-shoot. Rebuilding them was nearly not possible because NOBODY knew what capacitor to use (the requirements of the capacitor are critical!!!). The plastic case coils look alike on the outside. However, inside, some were fairly well built, others were total junk. I have never heard of a reliable way to tell them apart by eye. After Ron P and others got things going in the right direction, people found that many of the plastic case coils can be tested on a HCCT and be found to be good. Many others will not set up and work correctly on a HCCT. Beyond that, the quality of the wiring inside is dicey at best. Even if one checks out and adjusts nicely, sometimes they just quit because the poor workmanship inside breaks.
When I was working on my first T, I was having issues with the original coils I had. So I bought two plastic ones to use as comparison coils. Both worked okay for awhile, then one of them just quit. The other, I used as a spare for several years. The problem was somehow they would wind up together and it would often be difficult to remember which one was bad. I eventually solved that by removing the points from the bad coil (being the way I am, I wanted to try to fix it, so i didn't throw it out). And, eventually, the second coil also just quit working.
About ten years ago, working on another T, after a few with after-market ignition systems, I was determined to get back to more stock ignition model Ts. By that time, I had acquired a fair number of old wooden coils, so I began rebuilding a whole bunch of them. After only a couple minutes to determine that the plastic coils I had did not wish to cooperate and be taken apart? I finally did throw them out.

Over the years, I have known several people that had plastic case coils, that worked very well for many years. I know that they have been made by different people over the years. But how do you tell a good one from a bad one? Because, from what I gather, the good ones are good. But the bad ones? Really should be tossed.

[Mark Gregush]

The capacitors in them can be replaced. The side cover is just held on with the potting tar. It is a bit of work to work the side off, but can be done. Just because someone said they are all bad, without checking can't say that would be the case. Some people in the more humid parts of the country like then because they don't stick in the box.

[Don ellis]

I checked them with an ECCT, all caps are bad. I’ll give replacement a shot.

[R.V.Anderson]

I believe that the plastic coils with the yellow labels are 24V units that won't work well in a T. They are for electric fence usage.

[Mark Gregush]

Thank you RV for that bit of info.

[Steve Jelf]

Based on varying experiences by different people, I suspect plastic coils are like reproduction New Day timers or currently available tire tubes—some OK, some not.