6V to 12V, anyone done it?

CorneliusRox

CorneliusRox

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I've got an old TO-30, and the 6V battery died. I tossed a 12V battery I had lying around on it so I could plow my driveway yesterday (we got 3ft in MN...). I am not planning on leaving it , or at least not without doing a conversion.

I have a couple good 120A Jeep alternators on the shelf that I could rig up, and get rid of the generator, but what else needs to be done?

I also notices it is positive ground, which I'd like to change.



Here are my questions:

-If I change to neg ground, do I need to swap the polarity (swap wires) on the starter?

-Do I need resistors anywhere in the system to keep something from getting hot? Lights maybe?

-What needs to be done with the ignition coil? I bet it wont like 12V, but can I toss an ignition coil from any other 4 cyl into it, or could I even toss one from a 4.0L inline 6 (more spare jeep parts)? I don't know enough about spark plug systems apparently.





One more thing, it is on the brink of fouling plugs, and there's a decent amount of oil in the exhaust, and a slight knocking sound. I boro-ed the cylinders and they look fine, so I am thinking maybe the valve guides are crapping out? Thoughts? I don't have any experience with this engine.

Thanks guys.
 
BigPapa said:
I did it on my old Oliver Super 55. I think it was Korvis that offered a wiring harness with a resistor, new coil, and I used a GM alternator. Best thing I ever did to the old girl. I'm sure there's something on it here:

http://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=ferg&th=116059
Click to expand...

Thanks, I'll have to read through that when I have time.

I was going to build my own wiring harness. Where exactly did you have to put a resistor and for what? And did you have to swap the pos and neg on the starter for it to work?
 
I did the conversion on my old 6V VW Bug years ago when I was a kid and with the 12V battery and alternator/generator then converted the bulbs as they burned out. I left the 6V starter as it spun faster on the 12V but still worked fine.

The pos to neg ground conversion may be more problematic... I've never done it, but I would think you would need to convert EVERYTHING electrical in that type of system to prevent shorting out a component or the battery...
 
Chris Tobin said:
The pos to neg ground conversion may be more problematic... I've never done it, but I would think you would need to convert EVERYTHING electrical in that type of system to prevent shorting out a component or the battery...
Click to expand...

I am not worried about shorting anything, I am just worried about polarity being the opposite. I might redo the entire wiring harness with 30amp relays for some bright lights, 60+amp alternator, new 12V battery, condenser, and a 12V ignition coil.

I was thinking of leaving the starter, but seeing if I can get a different starter relay, and possibly making a button instead of the stick shift starter.
 
I would definitely rewire the entire harness if swapping from positive ground to negative ground!!!
 
Chris Tobin said:
I would definitely rewire the entire harness if swapping from positive ground to negative ground!!!
Click to expand...

I am planning on it, but I'll probably try and get it running with the old harness first to test out my thoughts on everything. Is there a reason why you'd be worried? I can't really think of one.

The wiring on this old tractor is insanely simple though.
 
CorneliusRox said:
Where exactly did you have to put a resistor and for what?
Click to expand...

The resistor was already in the harness. I'm an electrical idiot, so I may be calling it the wrong thing, it may have been a diode. From what they told me, whatever it is, it serves as a check valve to keep power from "back-flowing" to or from the alternator. The first harness I received had the resistor, or diode, backwards, and the alternator was not charging. it took me forever and several calls to find the problem. Swapped in the new harness and it's been working great for 15+ years.
 
BigPapa said:
The resistor was already in the harness. I'm an electrical idiot, so I may be calling it the wrong thing, it may have been a diode. From what they told me, whatever it is, it serves as a check valve to keep power from "back-flowing" to or from the alternator. The first harness I received had the resistor, or diode, backwards, and the alternator was not charging. it took me forever and several calls to find the problem. Swapped in the new harness and it's been working great for 15+ years.
Click to expand...

I changed pretty much everything to 12V yesterday.
What you're describing is a diode, but I don't know why you'd need one?

I picked up a used GM10SI alternator (single wire out and internally regulated to 12V) for $40 with a generic mounting arm that ended up working great.

I put a ballast resistor in before the ignition coil, and I left the stock 6V coil since I couldn't find a 12V one yesterday and it looks like my jeep one might not make for a robust one. I'll find one and swap it.

Then I bought a 12V condenser for the distributor.

I didn't buy a new battery because they didn't have one that'd fit well, so I just jump started it, but it seemed to work great and turn over fast. Also, the battery I had used before apparently was junk and only was alive because it had just come off the charger.

I still need to do the lights, add a starter button, and redo the entire wiring harness. I'm also going to adjust the valves to try and get rid of the oil in the exhaust a bit, but I am thinking it needs a valve job. That might be a warmer weather project though.


Any one know of spark plugs to put in this thing? Mine seems to have some sort of adapter on it for the plugs... Not sure why and I can't believe it was made this way.
 
D21 champions plugs should fit it. Make sure to get the resistor for the distributor because other wise you will eat points like its your job.
 
99GreenCummins said:
D21 champions plugs should fit it. Make sure to get the resistor for the distributor because other wise you will eat points like its your job.
Click to expand...

Yeah, like I said, I ran a ballast resistor before the ignition coil, so that means it's upstream of the distributor.

Thanks for the plug info!
Do you know of any newer age plugs that are possibly iridium? If not I might take some measurements and call up NGK.
 
So a little more homework, and I am thinking I can swap my mag ignition coil to a regular automotive, swap to automotive wires (might have enough lying around), and run resistor plugs (or not, still a little unclear on that), and have my system be more efficient. Then I can gap the plugs larger, and get a better burn without increasing temps.

Thoughts?
 
Resistor plugs are mainly for electrical interference if I remember correctly. Shouldn't need them on your tractor.
 
Two different things... If I remember correctly a Ballast resistor was used to drop the voltage to the ignition points so that they would not burn out prematurely while the coil could still get the full voltage to fire the plugs... But it has been a LONG time since I have messed with stuff like that so I could be wrong.
 
Chris Tobin said:
Two different things... If I remember correctly a Ballast resistor was used to drop the voltage to the ignition points so that they would not burn out prematurely while the coil could still get the full voltage to fire the plugs... But it has been a LONG time since I have messed with stuff like that so I could be wrong.
Click to expand...

I've been digging a bit, and I think it's more like this:
The resistor goes in before the coil and it lowers the voltage at the coil, which in turn lowers the voltage at the points. The condenser would be dealing with pitting, but is also lowered by this resistor. If you figure that a 12V coil might put out 40000V, then if you toss a resistor on it to drop it to 9V, it will only output 30000V.

I am not sure though, it seems like there is a lot of speculation on the internet about this. I am surprised there are no clean cut answers.
 
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