8 volt battery in 6 volt car

I am just looking for a knowledge based cause and effect of this set up has on the various electrical components of a Model A.
Sofield
 
Change this , change that , boost up whatever??? I don't know! , I guess that I have just been darn lucky. Drain the water in the fall, push it in the garage, roll it out in the spring add water ( the WPL) and starts right up … every time for the last 49 years. All stock , like Henry built it. Only one road incident in all that time and 13,000 miles - stopped … bad condenser.

Joe B 31 Coupe
 
Millions of Model A's (and later v-8's) were built and ran very happily on 6 volts. It ain't broke!! It doesn't need to be fixed!! Going to higher voltages masks problems. It doesn't fix them.
 
I would have to say, stick with 6 V, clean all your connections, make sure your battery cables are good, and it’ll crank over like crazy. In my opinion eight volts is just a Band-Aid fix to cover up another problem.
PS. I’m going to install a bolt in my vacuum port to adjust my timing.
 
In my opinion, converting to 8 volts is either a band-aid or it is dinking with something that ain't broke just for the sake of doing it.
 
Think of using an 8v battery as the 6V components have to run at voltage and power d1ssapation up to 25 % more than they were rated for. Example - the starter spins faster with more power and the bendix smacks into the flywheel with more force - can it take it? Maybe or maybe not, but they were not designed for the extra force.
 
Were 6 and 8 volt bulbs marketed separately? This has got me to thinking,I have some NOS bulbs,and they are marked 6-8 volt.I have an old Tung-Sol bulb display,that just says 6-8 volt also.While I've never actually looked,I can't recall seeing any 8 volt specific bulbs.I have a big Marquett battery charger,I know it says 6-8 volt on the tag so I gave it another look.there is no switch for the 6 or 8 volt.I drove a 50 Ford pickup for a couple of years that had an 8 volt battery in it.An old mechanic told me that if I took the time to check I would probably find that the battery was being maintained at 6 volts by the stock charging system.He said the 8 volt battery was most likely a feel-good thing by the previous owner.
 
I suspect the 6-8V spec was a feel-good thing pushed by Edison and Westinghouse. They're 6V bulbs. Obviously, running them consistently at 8V will shorten their life.
 
If you want to run an 8 volt battery its simple enough to build a 2 volt voltage reducer with 3 power diodes in series. Check the maximum current draw, then use diodes that are rated for at least double that. Ex: 70 amp diodes are about $5 each on ebay. I don't see any need myself to use anything besides 6V but if its your car, do as you want. Maybe if you have a leaky carb the 8 volt battery will seal it up? :)
 
We buy all these neat old cars and want to experience the unique-ness of having a Model A. Isn't it kind of baffling that one of the first things many of us want to do is mess with some of the basic parts?
 
I have used an 8 volt battery on an old 6 volt tractor, just because it was an easy choice to keep the tractor starting well. But on a Model A, considering, there is a reason 6 volts is not doing the job. I would venture the light bulbs will take the extra voltage but, my choice on my model A would be to figure out why 6 volts was not functioning right. Got a lot investing this ole girl and 6 volts should work.
 
Six volts will work , there really doesn't have to be a problem . There is such a thing as an improvement . My reason for setting up my roadster on twelve volts was that I p[refer a more powerful twelve volt system for the same reasons that most vehicles changed to twelve volts over sixty years ago .

Twelve volt bulbs are readily available . I have NEVER had a problem with the original MODEL A generator or starter when used on twelve volts . I run mine positive ground and no wires will need to be changed or reversed . The biggest thing is installing a twelve volt battery and either using a three OHM coil or installing a resister at the six volt coil . I am now using the Fun Projects twelve volt can style voltage regulator with good results . I have also used the original type cut out on twelve volts . My repro horn blows strong enough on twelve volt to be a good warning device when needed Most six volt accessories will need a voltage resister .

If a person wants to run negative ground It will be necessary toi reverse the wire connections at the ammeter and the coil . Of course the battery will also need to be hooked up negative ground .
 
Magicbox51 said:
We buy all these neat old cars and want to experience the unique-ness of having a Model A. Isn't it kind of baffling that one of the first things many of us want to do is mess with some of the basic parts?
Click to expand...

Isn't that the way it has always been with the Model A? Look at all the accessories that where available "back in the day". :p:p

If you get a chance, check out the book "Those Wonderful Unauthorized Accessories for the Model A Ford". https://www.snydersantiqueauto.com/...OOK?fromCategory=Products/books/model-a-books Fun read.
 
Last edited:
I've got a 40 coupe, still 6 volt, hi-comp heads, dual 97's, headers, electronic ign., a proper grp 2 battery. Spins over just fine ! !
I cleaned ALL the grounds and cables and added another ground strap from the intake to body ground. No problems. FWIW 8V is a bandaid. JMO
Paul in CT
 
You must log in or register to reply here.
Back
Top