Original Ignition Coil
 

Re: Original Ignition Coil
 

The typical "old" ignition coils put out 5,000 to 6,000 volts, dunno what an original Model A coil puts out.
Maybe someone with an old ignition analyzer scope can supply an actual reading.

Re: Original Ignition Coil
 

My original slant pole coil puts out about 12,000 to 15,000 volts.
Check on Vince's website and he might list the specs. I might be able to find them somewhere, but don't hold your breath.

Re: Original Ignition Coil
 

Supposedly the Slant Poles were a little higher voltage around 15,000 volts.

Re: Original Ignition Coil
 

Voltage is dependent on rotor air gap, plug air gap, dwell, compression and fuel mixture. A scope will show you how variable it is. Good for others to know. I suspect Bob that you were looking for maximum value. Think of it as a lazy thing; only climbs as high as it needs, to find ground.

Re: Original Ignition Coil
 

On an OLD coil, it's a good idea to remove the secondary wire at the coil & crank it over to see if spark is jumping THROUGH the COIL TOWER.
Bill W.

Re: Original Ignition Coil
 

Wet your finger and put it in the hole, touch ground with your other hand.

If you just say ouch then it is like 5000 volts.

If you go ouch then say SOB then your close to 10000 volts.

If you say GD, SOB then you are near 15000 volts.

If you say MF GD SOB then your around 30000 volts.

If your repeat 30000 volts several time then you are around 50,000 volts.

At least that is my experience.

Re: Original Ignition Coil
 

Something like this?

Re: Original Ignition Coil
 

Thought the old rule of thumb was 1K volts for every 1 thousands of an inch on the gap. If that is close then about 35K volts for a 35 thousands gap. Doubt if it is quite that high, but 30K volts would be close

Re: Original Ignition Coil
 

Thats a good one and I would say you are right on !!! I got shocked once by my 40.000 volt Flame thrower coil . I have been VERY carefull not to let it happen again . All of the vender replacement coils that I have tested with my jump spark coil tester have failed to jump a 10.000 volt gap . I read somewhere that the original slant pole coils put out around 20.000 volts .

Re: Original Ignition Coil
 

I've run the old Mallory Bee Hive coils that have been said to put out 30.000 volts , I could feel a good improvement in performance . The Bee Hive coils are oil filled . By the time that I figured out what I was doing wrong , I had already went through a few of them . Oil filled coils need to be run with the tower pointing upward .

Re: Original Ignition Coil
 

Hey Purdy, glad to see you back on the barn again, Dave.

Re: Original Ignition Coil
 

I don't know what the originals put out

But a fellow came round to my house last year in a 29 Canadian Tudor
that he imported a few years ago .

It still had an original Slant Pole Coil on it and it was working fine.

Funny thing is he took it off when I told him "that coil is 86 years old"!!!!

Re: Original Ignition Coil
 

Thanks Dave , I'm happy to be back !!!

Re: Original Ignition Coil
 

I've had good luck with the old slant pole coils . I've bought rusty , dented slant pole coils at swap meets for as little as five dollars each . After a good clean up all of the old coils have worked , so far. The service bulletins mention carbon tracks that can extend from the tower up to the metal trube of the coil and short out . I think that the carbon tracks is about all that ever goes wrong . The tracks can usually be scraped off with a pocket knife and all will be good again . The original model A coils are tar filled and sometimes called solid coils . The old guys , way back when use to tell me that coils seldom if ever gave problems .