Original coil test?
 

Suppose one found an original coil at a swap meet and had no way to test it on a running engine, is there a way to test it before spending big bucks? An ohm meter or ????

Re: Original coil test?
 

Use the "untested" as a bargaining chip and buy low. Every coil I've ever bought at a swap meet has been good.

Re: Original coil test?
 

Only way is on a "hot" hour+ running engine. bench tests are mute. Might get lucky but carry another which you would do anyway.

Re: Original coil test?
 

There were testers in the day that would heat up the coil when testing but today, no new stuff sold.

Re: Original coil test?
 

My tester actually has a 'heat' function setting but I am not sure how it works because I can never feel the coil's case get warm.

Tom, maybe it was just bad luck but the majority that I have found at swap meets and on eBay actually have been marginal at best according to my tester. They work and throw a spark however it is weak. A coil tester is a great item to have!

Re: Original coil test?
 

There is only one way to test a coil and that is with a coil tester.

You need to spark check it with the tester and then let the current warm up the coil for a little while then spark check it again to see how much loss of spark you get. That means you need to carry a battery and a spark checker.

Better to just assume the coil is bad and pay accordingly cause odds are real good it is bad.

Re: Original coil test?
 

Arlyn,

If you are at a swap meet and take an economy digital volt ohm meter with you the primary should be in a straight pole 1.2-1.4 ohms
If you don't get that it's a leverite ( leaver rite there) .
If the primary ohms ok it has a shot but as the guys said it takes a coil tester to load and heat them up to determine them good . You probably remember my ford heyer sets which is what I use .

I don't give any more than 5-10 for an original mode a coil that is untested, and that us probably generous . If you throw the meter on it at the swap it might not help you bargaining power any but at least you have a hint
Larry Shepard

Re: Original coil test?
 

It is possible to pull the coil apart and load in a modern coil.
You just need to find a 6 volt coil that fits.

I have an epoxy coil that a friend Xrayed and confirmed there was enough room to reduce the diameter enough to slip into an original can. The problem is I have not seen another coil like it.

Re: Original coil test?
 

John Holland had some but he has exhausted his inventory of replacement coils that fit inside the original can. I would like to find what it takes as I have a couple of dozen original coils I would like to restore.

Re: Original coil test?
 

hmm

Re: Original coil test?
 

The good slant pole coils are hotter than the late straight pole coils used in 30-31.
The slant pole coils put out around 20.000 volts . Like Tom W , I've never bought a used model A coil at a swap meet that wasn't good . I've been running a slant pole coil on my tudor that I paid five dollars for, for over 15 years. The Champion C 4 plugs in the tudor run clean . These coils are tar filled and don't leak and over heat like later oil filled coils. About the only thing that ever goes wrong with these coils are carbon tracks on the bakelite that reaches up to the metal part of the housing . Carbon tracks will look like small cracks or lines from the bakelite or what ever to the metal part of the housing . Carbon tracks can be scraped off with a knife and the coil will usually function as normal . Carbod tracks and coil problems are mentioned in the service bulletins .

Re: Original coil test?
 

Are you saying "guts" or the whole can?
The Bosch 6V coil guts should fit...

Re: Original coil test?
 

I tried all 5 of my original coils when I had the delivery running and only one gave a nice hot spark. Did not run it long enough to see how it was once it warmed up good. Rod

Re: Original coil test?
 

Brent,
You might try Skip Haney in Florida. I believe I've inquired before when speaking to him and he didn't want to do them but he does V8 coils. Just a thought....
There's still enough of the originals around that once tested and the best used they are still somewhat plentiful.

Re: Original coil test?
 

I have read many times on the barn that oil filled carbs are not as good as others. How do I know an oil filled coil when I see one?

Bill G

Re: Original coil test?
 

Give it a shake at least for the more modern coils you can hear the oil "slosh" around