'51 B 12 volt conversion

[620 John]

At some point I'm going to covert my '51 B to 12 volt. Might be pushing snow so it would be nice for starting if it's -10F outside. Plus I might change the lights to something brighter. I know this topic has come up from time to time but I'd like to get some more specific information before I decide how I'm going to do it. The tractor is more of a workhorse than a parade queen. However I don't want a butchered up ugly mess when all said and done.

Currently the tractor is 6 volt positive ground with what I think is a reman generator (it says Wilson 110390 so I think it's a Delco reman). It also has a Wico XB distributor on it. I know this distributor isn't the best but it seems to be working pretty good (I've got new points, condenser, rotor, cap, and coil). For the time being I'll just add a ballast resistor so I don't fry the coil. Some day I might upgrade to a Delco distributor and put electronic ignition in it. Here's my thoughts:

Charging:
I'm leaning towards going with a 1 wire alternator. This would really be beneficial if I want to put better lights in it. If I go this route I know I'll have to switch a few things over to run negative ground. I'm not familiar with what specific alternator models are out there though. Would also like to know the best way to get it mounted and what pulley to use. Another thought is if I want to keep it looking original how hard is it to convert the generator to a 12 volt?

Starting:
I know my starter needs to be rebuilt. Little while back I did a free running Amp test to see how many amps it was pulling. Using a Fluke clamp amp meter and fully charged battery the starter was pulling about 110 amps. Spec in SM-2029 is 60 amps for the 1107942 starter. I did the test with starter still installed and just took the bottom cover off and hit the starter switch with my finger so the bendix wouldn't engage the flywheel. From reading past topics it seems like a lot of people don't have any issue running a 12 volt battery on a 6 volt starter. However if I'm rebuilding the starter it might be wise to change whatever that may be needed to run 12 volts. I see someone on Ebay sells some sort of conversion kit. I'm also going to replace the battery cable but won't do that until I know for sure which polarity I'm going to use. Will also run a ground cable to somewhere on the frame instead of the battery box.

Ignition:
As I said before this tractor has an XB on it so I know I'll have to add a ballast resister. I'm thinking one of those resisters off of a 20 or 30 series tractor should work. I will switch the wires around in the coil if I go with an alternator. I'm sure some day I'll switch to a delco and electronic ignition but that'll be another time.


My main questions are:

What model 1 wire alternator would you recommend?? I see Steiner sells a 63 Amp (p/n ABC418) would that work?? What type of pulley?? Best way to mount it?? (pics would be nice). How hard is it to convert the 6 volt generator over to 12 volts??

What's involved in rebuilding/converting the starter for 12 volts?? Tips/tricks for rebuilding a starter??


Thanks

 

[Loosehandle]

Just put a good wico X magneto on it and
leave everything else alone. I have a 6
volt B in Wisconsin and it starts great in
winter.

 

[J.Wondergem]

You don't have to do anything to the starter, unless it already needs rebuilding. The 6 volt starters have a heaver winding in it than a 12 volt.

 

[matthies]

Just don't free wheel the 6V starter with 12V, armature doesn't like it. Been using a 6V starter on a farmall H for 20 + years.

 

[used red MN]

I for one have a negative opinion of one wire
alternators. No direct experience with them but I often
hear the complaint that they require to rev the engine
way up to get them to charge. I would recommend a
Delco 10SI, which can be called a 3 wire. Only two
wires are required because on of the small spade
terminals just requires a short loop around to the
output post on the back. They are available at all parts
stores, just ask for one for a 79 Chevy pickup with no
A/C. Just remember once you install the alternator the
tractor has to be switched to negative ground. If you
forget and hook it up essentially reverse polarity for
the alternator you will ruin ..let the smoke worms out
of.. your new alternator. You are onboard with the
ballast resistor. You will need to swap the primary coil
leads side to side so the wire to the distributor goes to
the negative coil terminal. If you have an ammeter the
wires will need swapped side to side on that as well. I
would not recommend staying with a generator, that is
one of the main reasons I like 12 volt conversions is
you can install an alternator and get away from the
troubles of generators and especially regulators.
Finding a good quality regulator that does not cost as
much as an alternator is getting more and more
difficult. I am attaching a wiring diagram for installing a
Delco 10si alternator, some of it may need a little
tweaking to match the Deere, for one the starter
engagement switch is right in the battery cable circuit
and I do not believe it is a solenoid.
Semi generic 6 to 12 volt wiring diagram.

 

[Mike(NEOhio)]

I have a 51 A that is 12 volt. Did the B stay with 6? Mine cold starts good as long as the batteries have enough to roll it over.

 

[620 John]

Used Red MN:
I like the wiring diagram. I too have heard people say the one wire won't charge unless revved up a little. Wiring up a 3 wire alternator shouldn't be an issue since my B has a key switch.

Mike:
As far as I know all B's were 6 volt from the factory.

 

[8850dave]

John Deere made a kit to convert the late B tractor to 12 volt, I actually found a couple and installed 1 on my 1951 B tractor it included a new
battery box for 2 6 volt batteries

 

[Rusty wheel]

I put a one wire Delco alternator on my 40-W. Changed the amp meter to a volt meter, installed a key
switch and 12 volt bulbs. Works great. You only have to rev up the engine when you start it to excite
the alternator. Then it will continue to charge at any rpm until you shut the engine off. I mounted
the alternator on the same mounting as the generator. Install a 12 volt coil and reverse the leads on
the volt meter.

 

[Leroy]

When I converted my 49 B to 12 volt I just used all pars needed from a square back 45 combine. Should have been able to fide a different pully to get it to chargin at slower tractor engine speed than the combine engine but for field work did OK.

 

[620 John]

Thanks for all the input. I'll probably go with a 3 wire Delco 10 SI. Eventually I'll rebuild the starter. Right now I'm getting a few parts rounded up to get this done. Hopefully in the near future I'll post a follow up thread with pictures when I get it converted.