12 VOLT Regulator for early 8N

Hi Folks - First post here, although I've used the forum as a resource and entertainment for quite some time...
This may be a little lengthy, and I apologize in advance... as I need to give you the whole story. in order to maybe get some creative advice.
I have an early 8N with the front mounted distributor, and although it defies most of what I've read, my grandfather simply replaced the 6V battery with a 12V about 40 years ago, and it has been running ever since with original 6V coil and generator... A short booster cable to ground the fields, bypassing the 6V regulator to make it charge . Recently while replacing the water pump, I decided to change the cracked dist-cap, rotor, points, etc, etc... only because I had the hood off anyway.... The tractor did not like the brand new 12V Coil I put on, so back to the 6V coil and runs like a dream...
(I know..... shouldn't work, but it does, and I really don't want to go to an alternator if I can help it)
Anyway - I tried to replace the voltage regulator with a 12V to avoid the booster cable trick... and ran into problems... Most regulators do not "ground the field" like the original does.. so I'm either looking for a 12 volt regulator that does. Maybe someone can direct me to a regulator choice... OR I'm thinking about maybe setting up a couple identical resistors in series across the 12 source, to create a 6V reference point for the original regulator...
Pretty Crazy, I'm sure... but would appreciate any feedback or thoughts.

Thanks in Advance

" only because I had the hood off anyway"

You do know that it's not necessary to remove the hood to change the points, right?

" The tractor did not like the brand new 12V Coil I put on,"

Of course it didn't. That produced too much resistance in the ignition circuit.

You have 3 reasonable choices here:

Put a 6v battery in it & a new 6v v/r

Put an alternator on it w/ your 12v battery & forget the v/r

Get an 12v B circuit generator & v/r to go with it.

Your call depending on how much time & money you want to spend.
75 Tips

Thanks for the quick response Bruce - and yep, I've done the points before... Was actually for the water pump that I decided to get the hood out of the way... and just decided to clean a bunch of stuff up (re-wiring etc)... when it was all so handy...

Anyway - I'm mostly curious about your "B type gen and reg" comment... I was not clear on the A vs B systems... but your comment caused me to do a quick study....
Given my current situation...(tractor running fine on 12V, just not auto-regulating), would a "12V [u:d150d6ea57]A[/u:d150d6ea57]-circuit regulator" not do the trick for me?

Yea, with a 12v generator. You have a 6 volt
generator.
75 Tips

It is full fielded all the time, so I take it the tractor hasn't run
for long enough periods of time at once to boil the battery?

If that's the case and it's ran that way for 40 years AND you're not
going to change the running habits of the tractor, why change it at all?

I have not had good luck finding quality voltage regulators lately.
If you put it back to 6V, I would keep the original VReg.

wow.. you are going to run a mile to gerry rig that thing to death.. when you could just fix it right.

Sure.. I know 10 things you could do.

my advice. fix it correctly... either get an alt and go 12v, or get a 12v genny and matched regulator.

Just as a bit of an update... After a bit more studying, I learned about the difference between "A" and "B" circuit charging systems... I was trying to use a "B" regulator when I needed an "A"... So, due to the popular disbelief that this would work, I decided to take the generator to a local starter/generator shop to have him bench-test it for me and pick his brain.... He was surprised to see that the 6V generator was quite capable of putting out >15V.... and with the "A" circuit 12V regulator, it worked just fine., He said in all his years, he had just never tried it before. So the tractor is back together, and running like a dream again.
PS - if anyone is interested, the following link, I found, is a really nice explanation of the "A" circuit Delco style regulator.
http://www.ruiter.ca/mc/info/PDFs/1R-116.pdf

"He was surprised to see that the 6V generator was quite capable of putting out >15V"

I would not be surprised by that for an unloaded generator.
Sustaining that voltage and the required amperage under load
would be the question. 40 years seems to point to the answer.
THAT, I am a bit surprised by. I've not tried it myself either.
Thanks for the update!

(quoted from post at 20:53:31 09/19/16) "He was surprised to see that the 6V generator was quite capable of putting out >15V"

I would not be surprised by that for an unloaded generator.
Sustaining that voltage and the required amperage under load
would be the question. 40 years seems to point to the answer.
THAT, I am a bit surprised by. I've not tried it myself either.
Thanks for the update!

Click to expand...

he unloaded voltage, I have seen & have no problem with that. What surprises me is that the field coils have not burned up at twice design current which means 4 times design power/heat!

(quoted from post at 22:35:49 09/19/16)

(quoted from post at 20:53:31 09/19/16) "He was surprised to see that the 6V generator was quite capable of putting out >15V"

I would not be surprised by that for an unloaded generator.
Sustaining that voltage and the required amperage under load
would be the question. 40 years seems to point to the answer.
THAT, I am a bit surprised by. I've not tried it myself either.
Thanks for the update!

Click to expand...

he unloaded voltage, I have seen & have no problem with that. What surprises me is that the field coils have not burned up at twice design current which means 4 times design power/heat!

Click to expand...

Short run times? It seems unusual to me too. Never tried it.