6v to 12v conversion 59AB (diver helmet)

R

Redmanbob

New member
Very very new to all of this. I read some threads here and there and got more confused imo. Hoping someone can DUMB THIS DOWN for me.

No vehicle involved: I am trying to use a 12 volt battery to test run (on a test stand) a 59AB with a diver helmet style distributor (coil attached) I'm wondering what resistor is needed too work with that stock coil and how exactly it should be wired (polarity) I'm attempting to get a bill of health on a used engine.

This will later go into a ratrod that will be wired 12v (very basic)
 
What coil are you running? Distributor and condensor do not care about 6v vs 12v or polarity. The coil is the main ingrediant.
 
Most 6 volt coils are 1.5 ohms resistance. If you want to run 12 volts through it and retain 4 amps through the points, (which is about all they will take without arcing and burning) add a 1.5 ohm resistor. Ohm's Law : R=V/A.

On a practical basis, just run it as is; if it is only for a short period, no damage will be done and you will only have a hotter spark. If you are just running the engine, polarity should be positive ground like the original system. Coils are more efficient when run with the correct polarity, although they will run if reversed.
 
Agree, 1.5 ohm or 2.0 ohm resistor. That little coil on the distributor is about 1 ohm in itself. You will then have about 3 ohm total in the circuit, about right to get 4 amps when being pushed by 12 volts.

Yes, coil does care about polarity. Feed negative to the coil. Ground the block to positive.
 
Redmanbob said:
The OEM coil that is "attached to the distributor" (divers helmet)
Click to expand...

Sorry duh.. You stated that in the first statement. I was half asleep, sorry.

Jay/Chicago has steered you perfect. Keep it positive Ground. The factory ohms is Coil .6 abd resistor .8 so 1.4 total or around there. So you need to be around 3 total and keep it positive ground.

For just a quick start up I would just go get a 1.5 ohm readily available locally.
 
So the post on top of the coil will connect to neg post from battery (-) ? I'm getting no spark that I can see by grounding a spark plug to a nut on the head or an arc from wire to the plug. It's cranking like a mofo! compression is a pretty even 80psi or 120psi on all 8 depending on which POS gauge I use. I attached a drawing and pict. Also confirmed continuity of wire battery through resistor to coil post.

I guess I don't get the image upload concept

Quick update, I reluctantly pulled the coil and condenser so the internals were visible. Removed the wire caps and cleaned the points. reassembled and BAMN it fires on ? # of cylinders.

Can the starter lead be removed then turn the engine by hand to see the points fire inside the housing ?
 
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I have done this exact thing before, but I cheated and used one of the adapters that Speedway sells that goes on top of the Divers helmet distributor. This allows you to run any kind of coil.
 
I'll stop beating this horse very soon hopefully. I'm noticing the resistor gets "very" hot in a short time when the circuit is closed is that normal or is it the wrong size ?
 
That;s what makes it a resistor. It starts at low resistance when cold, and quickly builds resistance as it heats up.
 
A wire wound ballast resistor is mounted in a ceramic frame to protect from the heat that is generated. All of the Fords with front mounted helmet, crab, or rabbit ear type distributor had a 0.8-Ohm ballast resistor but they can't take 12-volts. Ballast resistors are available from most parts stores.

A 4-banger is easy to turn with the hand crank but the V8 is more difficult. It can be done. Ford had hand cranks for them for a long time but most folks didn't attempt it. The crankshaft has to have the ratchet bolt to use a hand crank and it need bearing block to stabilize it. A regular ratchet handle with socket if you just have a bolt in it.

Skip Haney updates the original coils to 12-volt if requested by his customers. He does water pumps and also has the torque tube center bearings. He doesn't do repop coils though. They have to be originals. The 12-volt coils would be 3-Ohm types so they don't need a ballast.

I'm not so sure about how quickly a wire wound resistor heats up. From my experience, they heat up pretty quick. The big three all used to have a 12-volt bypass that was in the starter relay circuit. They ran full voltage to the coil during the start phase and then it went back to ballast wire after it was running.
 
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