Crab distributor or ???
 

I am thinking of updating my 59a to a crab distributor instead of the helmet. I have converted the car to 12 volts, neg. ground and would like have a reliable coil/distributor. The old helmet distributors are pretty good if you are running 6 volts but not sure so much about going to 12 with them.

I have been working on one that has a traditional coil converted to 12 volt but not having much luck with it.

I would like to hear people who have done this and if it the results were good on going to the crab and using 12 volt components from members here. I am sure this has been done more than once.

I understand that there is an adaptor plate that can be used to make this up without having to swap the front cover.

What about going to a modern crab type?


Thanks in advance.

Re: Crab distributor or ???
 

Your helmet can be set up just like a crab (contact Mike @ thirdgen) the have skip rewind a helmet coil for you set up for 12v whatever polarity you choose & you will have a winner.

Re: Crab distributor or ???
 

The distributor doesn't care about the voltage or polarity you are using. The coil is a different story, both matter.

Re: Crab distributor or ???
 

I feel the earlier helmet distributors are better on 12 jolts than the crabs. The crab caps seem to develop carbon tracking leading to mis-firing etc.

Re: Crab distributor or ???
 

Didn't the 59 come with a crab dist??It;s a very good dist in proper working condition on either 6 or 12 v.
Gramps

Re: Crab distributor or ???
 

Thanks for the replies.

Thanks guys, I am burning up points very quickly. I was told to use a 1.5 ohm resistor which just did not bring the voltage down close enough at the coil. I tried a 2 and a 2.8 but still no go. I did check the resistance of the coils and they appear to be running around .48. Shouldn't they be higher like .8 or 1?

I am guessing that even at .48 maybe I can run 2, 3 ohm resistors and solve this problem, what do you think?

Re: Crab distributor or ???
 

Points burning indicate a condenser that is way out of spec.

Re: Crab distributor or ???
 

I should clarify that it is only the primary set of points that is being affected. The condenser is showing about .35 mf.

Re: Crab distributor or ???
 

Have you tested it when it's hot? Or over a period of time? The ability of the condenser to do it's job can vary greatly with both of these conditions.

Re: Crab distributor or ???
 

I should clarify that it is only the primary set of points that is being affected. The condenser is showing about .35 mf.

The resistor is supposed to be a 3.0 but is showing around 2.8.

Not enough to get to 3.5 or 4 volts needed at the coil which shows .48 ohm resistance.

Do I in fact need 2, 3 ohm resistors here?

(reminder I have converted this to 12v, neg ground).

Re: Crab distributor or ???
 

No but that will be next.

Re: Crab distributor or ???
 

Are you attempting to run an original Ford coil on 12v? The 1.5 ohm ballast resistor is what is normally coupled with a 1.5 ohm coil. You need something in the 3.0 to 4.0 ohms total in the circuit. A 0.48 ohm coil would need a ballast resistor somewhere in the 2.5 to 3.0 range. Not sure you are trying to run this type of setup, I would get a proper coil.

Re: Crab distributor or ???
 

I helmet with 11A internals properly setup on a sun machine will be better than a crab distributor in my opinion. As for coils, your primary total resistance needs to be around 3.0-3.5 ohms. Bosch makes a good 3.3 ohm epoxy filled coil, and standard makes a 3.0 ohm oil filled. As mentioned the condenser needs to be tested not just for a reading but also to be sure it holds a charge and doesn’t leak down too fast. Too much dwell can believe it or not Cause points of lower quality to prematurely burn as well. What is your dwell set to on your distributor?

Re: Crab distributor or ???
 

Just to add to the discussion on a helmet only one set of point will burn up , they use a make set ( makes the circuit) and a break set (opens the circuit ) ... The only set that arcs is the break set.......Get a 1.5 ohm coil amd use a 1.5 ohm ballast or a 3.0 Ohm bosch coil # 00012

Re: Crab distributor or ???
 

Can someone tell me where to find the part number on helmet to see which guts it has?

Re: Crab distributor or ???
 

The tang that mates to the camshaft has a stamp that will say either 68, 11A or 40B


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Re: Crab distributor or ???
 

Thank you.