Electrical: reasons to not convert to 12 volts

[colt45sa]

A friend of mine just bought a 1951 automobile. It is very, very solid but has been sitting since 1973. He is not a 'purist'. He had it delivered to a shop to get it running and the first thing the shop wants to do is convert it to 12-volts. I told him 'no' and gave him my reasons.

Please give me some of your arguments why that conversion should not be done (and not from a 'purist' point of view) other than it's a waste of money.

[TWChamp]

It's hard on the starter for one thing, because many don't change the starter.
If the shop isn't comfortable with getting a 6 volt car running, then I'd take it to another shop that knows old cars.

[BobPalma]

What Tom said in Post #2. BP

[StudeRich]

The common old story works for me: "they worked just fine when New!"

The only thing that contradicts that theory is that the is STARTER is likely no longer in like New condition, and needs to be PROPERLY rebuilt without internal dragging of the Armature on the Fields.

[RadioRoy]

The only real reason I can come up with is that many mechanics do not understand electrical systems. They might do excellent mechanical, paint, body work, but the wiring looks like a bowl of spaghetti.

Plus, when the old wiring gets hard, fiddling with it destroys the insulation. Many folks just cannot keep from fiddling with the wiring.

When I converted my 54 V-8 wagon, I built a custom starter, 12 volt motor, with the gears and Bendix from the 6 volt starter. Had to have the machine shop make a simple bushing as the 6 volt armature is larger diameter that the 12 volt armature, so the 6 volt gear and Bendix set had a hole that was too large. It was a simple conversion and has been working great for 25 years.

Running a 6 volt starter on 12 volts just does not seem like a good idea to me, regardless of how many people say it is OK.

Colt, what reasons did you give?

[colt45sa]

The only real reason I can come up with is that many mechanics do not understand electrical systems. They might do excellent mechanical, paint, body work, but the wiring looks like a bowl of spaghetti.

Plus, when the old wiring gets hard, fiddling with it destroys the insulation. Many folks just cannot keep from fiddling with the wiring.

When I converted my 54 V-8 wagon, I built a custom starter, 12 volt motor, with the gears and Bendix from the 6 volt starter. Had to have the machine shop make a simple bushing as the 6 volt armature is larger diameter that the 12 volt armature, so the 6 volt gear and Bendix set had a hole that was too large. It was a simple conversion and has been working great for 25 years.

Running a 6 volt starter on 12 volts just does not seem like a good idea to me, regardless of how many people say it is OK.

Colt, what reasons did you give?

My reasons are three fold 1) waste of money 2) many components have to be changed or added; change coil, change horns, change generator, change voltage regulator, add runtz to cut voltage to gauges, change all bulbs, add ballast resistor. Starter can take it for a while but will eventually be changed over. 3) Simple fix is to make sure battery cables are adequately sized, clean all terminals and make all terminals/connections are snug.

[SN-60]

It's hard on the starter for one thing, because many don't change the starter.
If the shop isn't comfortable with getting a 6 volt car running, then I'd take it to another shop that knows old cars.

No, this is simply untrue...a 6 volt starter will last indefinitely in a 12 volt car so long as it's given a rest every 15 seconds (or so) of cranking....An engine with no mechanical issues should start much quicker than that anyway!

[colt45sa]

It's hard on the starter for one thing, because many don't change the starter.
If the shop isn't comfortable with getting a 6 volt car running, then I'd take it to another shop that knows old cars.

From their initial recommendation I'd say that they were incompetent. However, because they present themselves as an Auto Repair Shop, they have more credibility than I and my friend is going to have his wallet lightened~!

[TWChamp]

No, this is simply untrue...a 6 volt starter will last indefinitely in a 12 volt car so long as it's given a rest every 15 seconds (or so) of cranking....An engine with no mechanical issues should start much quicker than that anyway!

It is true because in 1975 when my 1952 Land Cruiser 6 volt battery was at the end of it's life I was jump starting with my 12 volt battery. The car was well tuned and always started right away, but on the 4th day that I jumped with the 12 volt battery, the starter armature spun a winding out from high RPM, and it got wedged in the field pole shoe.
I used a screwdriver to push it back into place and coated it with clear fingernail polish, and it worked fine again. 12 volts is also hard on the drives.

[SN-60]

It is true because in 1975 when my 1952 Land Cruiser 6 volt battery was at the end of it's life I was jump starting with my 12 volt battery. The car was well tuned and always started right away, but on the 4th day that I jumped with the 12 volt battery, the starter armature spun a winding out from high RPM, and it got wedged in the field pole shoe.
I used a screwdriver to push it back into place and coated it with clear fingernail polish, and it worked fine again. 12 volts is also hard on the drives.

It's unfortunate your starter gave you trouble, but, once again, your 'backing a losing team' here Bob!

[TWChamp]

It's unfortunate your starter gave you trouble, but, once again, your 'backing a losing team' here Bob!

Not really. I've always had great service from 6 volt batteries and the last twice as long as 12 volt batteries. I usually get 6 or 7 years from a 12 volt battery, but always get 10 to 13 years from my 6 volt batteries. Tom

[SN-60]

Not really. I've always had great service from 6 volt batteries and the last twice as long as 12 volt batteries. I usually get 6 or 7 years from a 12 volt battery, but always get 10 to 13 years from my 6 volt batteries. Tom

More power to you Tom!

[bezhawk]

More power to you Tom!

Or less power?

[RadioRoy]

My reasons are three fold 1) waste of money 2) many components have to be changed or added; change coil, change horns, change generator, change voltage regulator, add runtz to cut voltage to gauges, change all bulbs, add ballast resistor. Starter can take it for a while but will eventually be changed over. 3) Simple fix is to make sure battery cables are adequately sized, clean all terminals and make all terminals/connections are snug.

I certainly agree with all those reasons. Too bad your friend won't listen. When someone else does the work, you have to accept it the way they want to do it.

[spokejr]

A friend of mine just bought a 1951 automobile. It is very, very solid but has been sitting since 1973. He is not a 'purist'. He had it delivered to a shop to get it running and the first thing the shop wants to do is convert it to 12-volts. I told him 'no' and gave him my reasons.

Please give me some of your arguments why that conversion should not be done (and not from a 'purist' point of view) other than it's a waste of money.

Good thing your friend isn't likely to be selling me that car, I'd want it returned to 6 V before paying money for it, or at least all the original parts.

Also, do these "mechanics" or "technicians" understand polarity? If that car has a positive ground and they install the battery as negative ground, without getting the starter re-wound, that car ain't cranking but the start sure will spin fast!

You're friend would probably be better served finding a shop that really understands older cars.