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Hello everyone,

I was wondering if I could use a 12 volt battery to start or turn over the motor in my Patrician with a 327 straight 8(6 volt positive ground) if I install a ceramic resistor to "knock down" the voltage to the coil?

Thanks in advance for your advice.

A simple and QUICK jump from 12 volts to a 6 volt system can be done without any special precautions. Just make sure it is quick (don't leave the 12 volt source connected for more than 5 seoonds or so), and that things like the radio and lights are turned off.

As O_D said, but since you can't turn the oil and gen indicator lights off without removing them, there would be a good chance they'd blow while trying.

Are you talking about a once-in-a-while type of thing or rigging something up to do this every time you start the engine?

There was a thread about using 12V for starting but the search couldn't find it. In a nut shell for a one time start just touch your 12V jumper cable directly to the starter terminal ( observing the correct polarity) but don't push the starter button as you will act as the solenoid. For constant use you could get a 6-12 battery (or 2 6V batts wired in series) and run the 12 to the starter solenoid and running all other power from the 6V tap on the batt. You would have to run a 12 V charging system.

Ehhhh---All of this monkeying around is unecessary if you just make everything right with the 6V system. Millions of people got to work every day with 6V cars before the industry fighred out they could eliminate a mile of copper from every vehicle by going over to 12V.

Check list:

What gauge cables are the positive and negative battery cables?

What condition are the positive and negative battery cables in?

Do the battery cables look like modern 12V auto store replacements? (hint: gauge size)

Did your vehicle have a braided ground cable originally?

Does it have one now?

Where is the Ground cable connected to the block?

What is the condition of the starter motor?

Have the bearings and windings in the starter motor been inspected since you acquired the car?

What shape is the Generator in?

Does the charging system work well?

Is this a fresh (over) restoration with lots of pretty paint on the engine block and starter?

It's not that difficult to get a 6V system to crank over fast enough to start your engine. They are less forgiving than 12V, but not that hard to figure out or make reliable.

Quote:


Here it goes again. I just can't seem to stay out of these discussions. Incert my two cents worth here: I fully agree with the above quote. 6 volts is fine.

Except for emergencies I would recommend checking the no-load voltage first and the cranking voltage second. For example, I had to cope with a situation of a car that was stuck up hill in a trailer with a dead battery. Now if you hook a 12 volt battery up to that thing and hit the starter, the voltage may only be 6.5 volts and the 12 volt battery is thus only dumping in boost amperes. The faster the starter is turning the less the current draw and thus the lower the likelyhood of damage to the starter. Six volt wiring is heavier to handle the higher current required to obtain a given level of power at lower voltage.

I dealt with one case where they were using a jump pack to start a 120 for years. And buying batteries by the wagon load. When I finally looked at the car I sent the regulator out for service because the ammeter was being pinned. I got a call that the unit was good (???) even after all that abuse. Next, I checked each wire and found that the reproduction harness was wrong and the generator was being full fielded all the time. After correcting the problem the charging system worked perfectly even after years of abuse. Although, I suspect low compression is hiding the true condition of the starting system.

I saw a film once of a brand new six volt car cranking over and it was really fast. Faster than any of these cars today, so I suspect that one day all these starters will finally die without new armatures and fields.

I agree, poor compression is why many engines don't want to start on 6v.

Drove my 51 200 some 300 miles to visit a friend. His neighbor stopped by and was amazed while I had the hood open. "You drove ALL the way out here on 6 volts"!! "Yup, that big black round thing down thee makes more while I go".

The next time I deal with a dead 6 volt battery situation I will jump a 12 volt battery and check the numbers. Usually I just put those cases on slow charge overnight because these parts are too scarce to subject to any abuse.

The cables I use have a lot of leakage which also buffers the potential.

Remember as well that I am talking about jumping from a 12 volt battery only and not a running vehicle.