[Gary_N]

At some point in time I need to convert to a 12 V system. I'm wondering what some of you have used in your conversions.

Thanks!

Gary

[51dyno]

Theres an old timer that rebuilds ford ts & as motors ,he has 6volt altenaters.I believe he"s from minesota.he has a stand at Iola every year.If interested I can look for his flyer,there is someone building altenaters inside generater housings.

[simplyconnected]

I used a standard Mustang alternator on my '55 Ford. GM also has a one-wire alternator that's very popular. These alternators have the voltage regulators already built in. Good ones are salvaged daily.

Depending on your demand, you may want to go with a 6-volt alternator. Let's do the math. A 35amp 6-volt generator or alternator produces 210 watts (that's like two 100 watt light bulbs). Headlights and the heater max it out.

A 12-volt 55amp alternator produces 660 watts. That's three times the power of the 6-volt system. 55 amps is the smallest alternator you will find because they go over 100 amps for police, taxi, ambulance, etc.

If you do the 12-volt conversion, all your wire sizes are more than sufficient. All light bulbs need to be changed as well as horn relay, and starter relay. Your gauges need a separate regulator, distributor coil needs a resistor, and your radio needs to be reworked. Your 6-volt starter runs well on 12-volts.

Sounds like a lot of retrofit, but well worth a Saturday afternoon. Want electric wipers or fuel pump? An alarm? Remote start? Power windows/locks/trunk release? Try finding them in six-volt. You already know about stereo stuff. Your cell phone, GPS, and inverters don't do 6-volt.

There's real good reasons why all the car companies abandoned 6-volt back in 1955, and never looked back. I'm glad I changed mine.

[Gary_N]

Simplyconnected: Thanks for the advice. I really can't live much longer with the 6V system. Right now it takes about two - five minutes for the car to actually start charging. The gauge shows a draw then eventually pegs to the plus side, and then comes back to a little above neutral on the gauge. I keep turning stuff off when I stop at a light, like the radio and heater blower.

Gary

[Leif Holmberg]

Way not put a new AC 6 Volt (look like the old one) insted of your old DC generator.Sears for Gener Nator.
Leif in Sweden.

[rlbleeker]

The simplest solution is probably to fix whatever is wrong with your system. Surely a new 1950 Buick didn't have this problem? Nothing wrong with 12V (obviously), but it's a bit of work to convert. In my experience, 12V on a 6V starter is not a good thing.

[simplyconnected]

Certainly, to be a 'purist' you must maintain original equipment. Back in the days of having one tail light, two headlights, and a heater motor, the 6-volt system worked marginally well. Generators only produce when they are turning VERY fast.

Long idle periods caused engine overheating. Vapor lock was very common on hot days. Some days, the ol' gal just wouldn't start. Bottom line is, these cars were built for specific service and for select areas of the U. S. Sustained mountain service demanded a re-jetted carb.

If a 12-volt system sensibly solves your electrical woes, then why not retrofit? Even at an idle, an alternator charges very nicely. It is hearty. Batteries and everything else in 12-volt is much cheaper and available everywhere. By the way, even after 1955, gauges were kept at 6-volts for many decades. The little 6v regulator is on the back of every Ford dash board built up to now.

I have run my 6-volt starter on 12-volts for three years now. The extra starting speed helps my engine start faster so I don't need to keep the key in "start" as long.

My choice was to retrofit and I am VERY happy I did. I come from experience; from both sides. If you feel strongly about keeping it stock, that is your choice.

[rlbleeker]

If you do go the 12V route and keep the 6V starter, it will crank very nicely; but remember that it will be drawing approximately twice the amps it was designed for and can overheat if cranked too long. I melted the armature in a straight 8 Chrysler doing this.

[simplyconnected]

Originally Posted By: rlbleeker

...it will crank very nicely; but remember that it will be drawing approximately twice the amps it was designed for and can overheat if cranked too long...

If you burned out your armature using 12 volts, you probably would have burned it out on 6 volts. You were cranking WAY too long and exceeded the duty cycle of that motor. It's all about current over time.

Starter motors are series-wound DC motors. The same current flowing through the field also flows through the brushes and armature. All the windings are coat hanger sized copper to carry tremendous amps which produces magnetism.

Heat is your enemy and speed is your friend. The faster your starter motor turns, the LESS amps it uses. Keep your engine tuned, and your start cycles will be short. 12 volts on your starter will turn your engine faster, which helps it to start sooner. By the way, your battery size becomes smaller when you go to 12 volts. So do wire sizes.

My '55 Ford is a 272 V-8, built with 6-volt POSITIVE ground. Using 12-v neg. gnd. works sweet. No changes. Hook starter to POS (on a 12-v starter relay), and turn the key.

[rlbleeker]

Not an expert here, but my understanding of series-wound DC motors is basically that speed is proportional to voltage and torque is proportional to amperage. At startup there is no counter-voltage, so it's simply V = IR. Doubling the voltage doubles the current. So when you hit the key it will draw approximately twice the initial amperage. As speed increases, the counter-voltage increases; decreasing amperage and torque. Speed will increase until the torque matches the load. Turning your engine over faster, means doing more work (compressing air, friction) in the same length of time, thus more torque and hence more amperage.

Now, these old starters are definitely over engineered and may handle 12V indefinitely; particularly with reduced cranking time. But I still think they are going to be more prone to failure than a correct 12V starter.