6 Volt Alternator

[Vintrader]

I have started thinking about changing the 6 volt generator in my 51 B3C to a 6 volt alternator. Has anyone done this? I found a few places that sell them anywhere from 30 to 60 amps. I really do not want to do a 12 volt conversion, I just got everything working 6 volt. But to have full time constant amperage seems like it would be a plus. Dutch

http://www.fifthaveinternetgarage.com/alternator/index.html

[Guest Nile Limbaugh]

I only have personal experience with 12V conversions, which have worked out well for me, but I see no reason that the 6V wouldn't work as well. I've seen a lot of them at local cruise-ins, some even on Model A F**ds. Nobody I have talked to had any complaints.

[Jim Roach]

I have a 6V alternator on my 52 B3B that was on the truck when I purchased it. Have never had any trouble with it.

Good luck, Jim

[Norm's Coupe]

I still have the 6 volt generator on my coupe. However, my brother in law has been running 6 volt alternators on both his 36 & 38 Fords for years. Hasn't had a problem with either. If my generator ever dies, I will change mine over to the 6 volt alternator too.

[Reg Evans]

What's involved with switching over to a 6 V alternator?

[Vintrader]

Reg, it does not look like much. See what these guys have to say. Dutch

http://www.fifthaveinternetgarage.co...tor/index.html

[Guest Nile Limbaugh]

Switching from the generator to an alternator doesn't amount to hardly anything, especially if the alternator is a one-wire hookup. All of the units I've bought came with instructions; basically you need to remove the gen. and regulator and the harness between them and connect the main feed. Finished!

[Jim Shepard]

I bought the 6V alternator from Fifth Avenue and I'm very happy with it. Yor do need to buy the recommended battery, though. It's the Optima SC6A and it's got 800 CCA! The only drawback is Optima doesn't make a tie down for it. Which reminds me - Fifth Avenue only offers a generic bracket for their alternator. Later, I'll probably have something fashioned that looks a little more like original. I took my regulator off and mounted a terminal block to run the harness through. It looks nice - almost original. You can see it just behind the hood strap.

[greg g]

Easiest way to connect a one wire type alternator is to abandon the wring for the voltage regulator, and connect the alternator wire to the wire that was connected to the BAT pole of the regulator. this takes the alts otput through the Ammeter then back to the battery via the pole on the batteryside of the starter solenoid. Be aware they your stock ammeter is rated for 35 AMPs so a 65 Amp alternator will probabaly peg it when putting out full juice. So an upgraded ammeter would probably be recommended.

[Guest Nile Limbaugh]

I fail to see the reason behind changing the battery. Voltage is voltage and if the alternator is properly controlled it shouldn't make any difference what it's feeding.

[grey beard]

Gents,

These 10 SI GM alternators are like nearly free at junk yards, and like $28 bukkz at Auto Zone. GM used a blue million of them for decades, so they're are many of them out there. Napa carries the 6-Volt regulator, which is all there is to the conversion. The regulator is simple to install, if you've ever had an alternator apart.

5th Avenue is right about pulley size, so you really need a smaller diameter pulley to spin the thing faster than the original generator. That, in turn means you need a shorter belt. Other than that, the switch is easy, and I have done many on farm tractors. I've tried using the original generator pulleys because they always fit the original belt width, but even though they fit the alternator shaft ususally, they are just too large in diameter. Alternators need to turn much faster than generators in order to deliver output at idle. If you were to spin a generator at that speed, the armature would fly apart from the centrifugal force.

Easiest way to mount an alternator is to use the original generator bracket on the block, and a piece of 3/8-inch all-thread through it, using six nuts - one on each end outside the bracket, one on each end inside the bracket, and the other two to position the alternator unit correctly for belt allignment. Works like a charm, and I have usually been able to adapt the original top belt adjusting bracket from the generator to work with the alternator, as well.

Switching the battery cables is necessary due to the fact that the alterntor diodes are polarity sensative, and are all made for positive ground, to my best knowledge. Otherwise, it is a simple switch.

IMHO, if one were starting out with an inoperative generator system, it would be cheaper to buy and install the system as outlined above than replacing a DC regulator and a few significan generator parts - like an armature or field coil set. LOL

[bkahler]

Gents,

........ Napa carries the 6-Volt regulator, which is all there is to the conversion. The regulator is simple to install, if you've ever had an alternator apart.

Dave, would you happen to know the part numer for the replacement regulator?

Thanks,

Brad

[Jim Shepard]

Fifth Avenue recommends the Optima for the cranking power. I looked for something in another brand (because the Optima is "funny" looking), but couldn't find anything that even approached its CCA's.

[grey beard]

The hot lick on some other 6-volt forums is the idea of using TWO Optimas in parallel, which will likely crank our average older flattie MoPar long enough for the radiatror to boil over. This is a neat idea for several reasons:

1. About 1600 CCA - like semi diesel Montana winter cranking power!

2. Two 6-volt Optimas will fit side by side in a Pilothouse battery compartment and look like they were made to fit there.

3. This system could be kept to full charge snuff with one of those nifty 6-volt alternators, the entire system would still be stock 6-volt, but you would have the added ability to run 12-volt accessories from the batteries using a series/parallel circuit - like the best of both worlds. :)