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Bobby Rodd

6 Volt to 12 Volt Conversion '37

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I'm thinking of converting my stock 6 volt system to a 12 volt on my '37 Special. Is this smart or is it not worth the effort?

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Redundant discussion. Some similar threads listed at bottom of page. Most "purists" will advise to keep 6v system. Be aware of all the things that will need to be addressed, everything electrical has to be changed or voltage dropped with resistors. After some "searching" subject on forum, and you feel educated, do as you wish.

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My 37 Special has been on 12 volts for about 30 years now and I see several advantages. All accessories offered such as cell phone and Gps plug ins are 12v as well as any of the sound system stuff. I'm not a gadget person so the big thing with me is 12v ignition, lighting, wipers, charging, heater motors, etc can be bought at a local parts store but the biggest was the 6v batteries just didn't seem to last as long as they used to. All the bulbs are a direct change out with 12v ones and the only gauge that needs a reducer is the gas gauge; the oil and temp are mechanical and the amp gauge doesn't know the difference between 6v amps and 12v amps. If you have a radio or keep the 6v heater motor then they take higher rated voltage reducers so I just converted both over to 12v units. I drive the snot out of mine (planing on a lap around the U.S. this year) so it also has an alternator and an HEI distributor which can be serviced or replaced anywhere along the road. Some like to see everything exactly the way it rolled off the line in 37 and to them I say, "jump in and follow me on a 4000 mile jaunt" and see who is the more relaxed during the trip. Babied or a trailer queen---NEVER.

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There are reasons for switching to 12 volt (some of them may even be viable), however, if you just use the correct type 6-volt cables (00) and clean all your electrical contacts, six volt works perfectly fine and far less work than doing all the modifications needed.

I bought a nice compact Stanley battery back/charger that sits nicely on my front floor. It not only serves as an efficient jumping system if needed, it also powers my cell phone, gps, and allows me to run Pandora for music.

As far as following Mr. McDarrunt, even though you're running a slightly larger engine than stock in your car, just tell me where you're going and I'll wait for you while sipping on some of Kentucky's finest. I'll even give you a day's head start, otherwise I'd be way too inebriated by the time you arrived. :cool:

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Edited by West Peterson (see edit history)

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It would be smart if there is a specific reason you need to do so. Otherwise, it's unnecessary for normal car operation.

West-I plan on sipping some of KY's finest today. It's awfully chilly down here right now!;)

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Got some for my birthday last night. I'm just 50 miles from Kentucky border and it's -5 here, going down to -10.

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I never have understood the aversion to 6 volt systems. For 50 years, give or take, virtually every car in the United States started and ran on 6 volt, and yes, made 4000 mile trips and then some.

It's been told over and over again, but the most common issue today, with antique car 6 volt, is grounding. If one grounds to the frame, a most original cars were, then you're relying on all the frame and engine connections to be clean and good conductors. Not going to happen. Run a good ground to a starter mounting bolt, and if need be from there to the frame also. Use 6 volt heavy cables, make sure your starter and generator are in great condition, and you won't have a problem.

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I agree with trimacar - my '38 Special has remained 6V, with good results. Large gauge cables and a few strategic redundant ground wires have done the trick. For example, for my taillights and parking lights, I have run a wire from one of the mounting bolts of the light fixture to one of the fender mounting bolts.

There are some advantages to 12V - like the newer sealed beam headlights, which are brighter. I prefer the look of my original lenses, so I will stay the course with 6V - maybe get my reflectors re-silvered. It's up to you and your priorities whether or not to convert. But the basic functionality of the 6V system can be very good, given good wiring and connections.

I totally appreciate hearing about Mr. McDarrunt's use of his '37. Awesome! Let us know if your lap of the U.S. brings you through Dayton, OH.

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I too plan on sticking with the 6V. As an electrical engineer, I take this on as a challenge. I replaced the pos cable from the batt and cleaned all the connx and it made a world of difference. When it warms up I am going to clean the contacts and do the test and adjust procedures on my voltage reg. I will probably go ahead and replace the ground strap as well. As far as 12v accessories, I put in a small 6v to 12v module I bought off fleaBay for about 12 bucks new. Provides 3A, which currently powers my vintage but 12VDC tach. There's enough left for iPod, GPS, etc if I need it.

Cheers, Dave

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For a non show car, I recommend the 6 volt Optima battery. It won't outgas and corrode the battery tray. It has great cranking power and much longer life.

Bob Engle

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All of our 6-Volt cars do just fine on their original 6-Volt systems. Clean connections are important. We drive all over the country without the need to make unnecessary changes.

I also use OPTIMA BATTERIES - they can be bought fresh through AMAZON at great prices with no sales tax and no shipping charges: $112.59 at this moment, ...

6-Volt, 800 cold cranking Ampere, size: 10 inch x 6-7/8 inch x 7-13/16 ...

http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=6%20Volt%20Optima%20battey

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Dave,

on one of the cars I initially shaped a wood block to fill the space, and later replaced it with a foam block.

on another car I used a pair of Optima batteries in Parallel which gave 2,000 Cranking Amps - not needed, but sure was a big help when other folks needed a jump-start,

and on another car the extra space was just perfect for storing a hydraulic "Bottle" jack and several tools,

another car had an Ex-Military Ammo Box filling the space and holds lots of small "stuff"

Edited by Marty Roth (see edit history)

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Thanks, Robin - hope your project is coming along nicely - would love to see your car, especially alongside mine.

We have volunteered to drive another bride - this one will be for the daughter of a friend, and will be on the west bank of the Mississippi here in New Orleans - tomorrow -- hope the weather holds - we are expecting temps in the 70s with partly sunny skies and a 50/50 chance of showers.

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Dave,

on one of the cars I initially shaped a wood block to fill the space, and later replaced it with a foam block.

on another car I used a pair of Optima batteries in Parallel which gave 2,000 Cranking Amps - not needed, but sure was a big help when other folks needed a jump-start,

and on another car the extra space was just perfect for storing a hydraulic "Bottle" jack and several tools,

another car had an Ex-Military Ammo Box filling the space and holds lots of small "stuff"

Is your generator sufficient to keep both Optima batteries charged or did you have to replace it with a modern 55-60 amp, 6V alternator?

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