Do plastic housing coils have the same internals as wood bodied coils? I'm thinking since plastic ones are probably newer maybe they have updated parts, or not? How many run plastic ones and/or recommend them? I'm not worried about being 100 percent original, just want to get my car running at it's best. Can plastic bodies be opened and resealed if needed?
I wasn't impressed with the quality of the ones I've seen. I did build a set once hoping to sell them. I liked to have never gotten them adjusted correctly. They were a pain in the behind. I kept them for 2-3 years, as no one wanted them. Finally sold them for less than I had in them. If you do open them up and re-pour tar, I suggest building a 'form' to hold them in their proper shape until the tar cools. They're pretty flimsy until it hardens.
They are useless, and have a capacitor so small, you almost can't see it.
They make great wheel chocks.The points are usually good because they did not work long enough to burn them.Salvage those.
Even had to struggle with one when I put one in a contraption I made to stun fish in a pond.
Been discussed here previously and were thoroughly knocked down. Don't want to do it yourself or lay out the $ for exchanging? PM me. We'll talk it over.
regarding new vs old, the newer coils typically have inferior parts in them (as Larry pointed out). Fixing this is more labor than fixing original wood bodied coils and no one does it more than once from what I can tell...they are a pain.
When you send out an original coil for rebuilding to a reputable rebuilder, you get:
1.a proper capacitor suitable for the voltage/capacitance needed.
2.The insulation resistance of the primary/secondary is checked with a Megger (most home shop repairmen will skip this...occasionally resulting in a coil that merrily buzzes but will not produce a spark when in use).
3. 80 year old solder joints reflowed
4. Point rivet adjusted (nearly always faulty from manufacturer) to proper travel of cushion spring
5. Points leveled with shims (boxes nearly always compressed resulting in impossible to adjust point angle)
6. Points installed level and square
7. Cushion spring tension adjusted
8. Point travel adjusted
9. Amperage or firing timing adjusted via 7 and 8 above.
10. Any voids left in the potting material replaced with same type material so as to waterproof and shock-proof the assembly as original
The point is, anything and everything that can or will likely go wrong with the coil has been remedied, so a properly rebuilt old coil is not inferior to a new plastic coil, by any means.
During the 40's, 50' and 60's trembler coils were made for many ignition solutions. The problem is many are made for different applications then the Model T.
When rebuilding after market coils always be skeptical of them working properly on Model T testing apparatus and the cars magneto.
Tommy, as you can see, every body shoots them down but I can say I have 5 T's and my 27 touring has 4 plastic coils in it for several years. It's done many long distance rallies and will do 50mph, a bone stock T, and the only issue I've had that one broke a piece on the points once, an easy fix.
Looks like it depends on who you ask. There is a set of plastic coils on Ebay right now that, according to the seller have been tested and showed 1.3 on a strobo. The X in the sides shows in at least one of them. Knowing they test at 1.3, how many would go for them?
It doesn't depend upon who you ask! It depends upon the coil your trying to use.
If you know what your doing with coils you know the difference. If you don't your guessing.
As Frank says some aftermarket coils will work in Model T............. and some will not.
I said "many" NOT "all" what is wrong with you guys?
Unfortunately I can't know if the ones on Ebay are the same kind that Frank in Australia has that have given him such good service.
I have been contacted by someone here in NC, about two hours from here ( six or seven by model T), who says I can bring as many coils as I want to haul and test them on his tester. Knowing that, how is the best way to know if a coil is worth opening to rebuild, besides the obvious busted wood or tar that has leaked out? I might gather up a few, replace the condensers, clean or replace the points, and make the trip. If I do, I will redo a dozen to make it worth the trip. Guess I'll gamble on a few of the cheap ones on Ebay. I guess I will buy all the untested, cheap ones even if they are good only for parts. I know how to pull tiny nails, remove tar, and solder wires so why not?
I think you will be glad you did.
I missed your question. Check the resistance of the secondary winding by putting a multimeter across the two contacts on the side of the coil. It ought to be about 3200 ohms. A good Ford coil will read that. Some of the other brands may not read that, but may work anyway. If it reads infinity, toss it. There's no fixin' it. Busted wood? Not a big problem if you keep the lid on the coil box. As long as the top is in one piece, some busted wood along the edges isn't a problem except for aesthetics. Tar running out? May not be a problem, so long as it checks electrically, but it obviously got hot at some point. Hopefully, not due to continuously buzzing on 12v. Read up on how to rebuild them and rebuild the ones that don't have open secondaries. Then adjust them on your buddy's HCCT. You'll be glad you did.
to your last question, I will post a sketch that I think Ron Patterson provided some time back. If they are still installed, separate the points with something non-conductive (business card is fine). Test continuity of all of your coils before you tear any down. They must pass all measurements for them to be salvageable.
Some of those black plastic coils have no tar in them at all and are very light, a real clue as to how well they will not work..
Some will almost work well, but not for long.
Most have a very small capacitor and will work on 6 volts DC and short out on higher Mag voltages.
I was told 30 years ago that you could use one with regular coils, if you put it in the end of the box, as they generate more heat and soon over heat.
Tommy, let me add one detail about Model Ts, and that is, everyone has an opinion on most every detail, like bands, oil, tires, spark plugs, coils, etc.
Buy those coils and then you can form your own expert opinion in no time at all.
In this case, I'm sure what it will be!
I had trouble free service from a set that came in my 1916 for many years. I only drive this car a few hundred miles a year, but I have never touched them. I gather my experience is unlike that of most who post here.
Some early ones were OK, but very few.
If they weigh about the same as a wood box coil, they are early.