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Decisions… Flathead V8, 6V or 12V

Discussion in 'The Hokey Ass Message Board' started by psychotitan, Apr 30, 2012.

  1. psychotitan
    Joined: Feb 27, 2012
    Posts: 15

    psychotitan
    Member
    from LA

    I know you guys have heard it 1000 times if not more.

    What to do...

    Just picked up this 48 Ford and loving it. Runs and looks beautiful. After driving it for more than 10-15 minutes, I can't start it for hours. Last night I tried starting it off and on for a number of hours (no more than 4 or 5 times) and the battery is dust. I just had it in the shop for an inspection and they say "it looks good... that's a 6V for ya!"

    Long story short, the car's sat for years. Guessing the battery is over 8-10 years old. Trying to decide if I A: pickup a new battery and risk the start up issues which I've read 100 posts on and different ways to trouble shoot or B: taking the money I'd put into a 6V new battery and replacing cables etc... and put that money into going 12V.

    To add to this short story that's quickly being too long... Do I find some guy off the street that's done it a number of times and offer him some money risking breaking something or spend the good chunk of change and hope the shop I take it too knows a bit more and has some sort of a warranty that they aren't going to break something.

    Would love to hear if anyone else has gone through my pains of just wanting a car that starts ~80% of the time (I understand it's old and needs some love).

    Keep in mind, I don't know **** about cars. (Yes I typed ****'s. I'll let you insert your own words. =) I see a auto mechanics class near in my future.

    Love these forums by the way. So much good information and stories.

    Sorry for the large picture. I guess I should learn how to attach thumbnails as well as how to work on cars. =) Also figured I'd show her off with the new shoes I just gave her.
    [​IMG]
     
  2. Ace'sSpeedshop
    Joined: Feb 8, 2011
    Posts: 289

    Ace'sSpeedshop
    Member
    from Washington

    I use to have a 48 Dodge that had the same problems that you have had. I would say switch it to 12v. I ended up running the car with a 12v just to start it and would unhook the cables.
     
  3. treb11
    Joined: Jan 21, 2006
    Posts: 3,940

    treb11
    ALLIANCE MEMBER

    two low $ things you can do yourself: 1) buy a shop manual for it. 2) start tracing out the wiring looking for wire breaks, loose terminals, bad grounds. etc.
     
  4. LSGUN
    Joined: May 26, 2007
    Posts: 1,353

    LSGUN
    Member
    from TX

    Definitely clean all the connections on the 6v system, I've had several 6v cars and it'll really help things out. My Model A coupe is still 6v and it fires right up fast and the lights are plenty bright. Nothing wrong with a well maintained 6v system, however one of the benefits of a 12v system is the ability to find a jump if that ever needs to happen.

    .02
     

  5. 46mercury
    Joined: Dec 19, 2010
    Posts: 85

    46mercury
    Member
    from livonia MI

    Been there done that. Hard starting when hot is a frequent issue with these cars.

    1. Get the fuel hose with the one-way valve to replace the one from firewall to pump.
    2. Get NEW proper sized battery cables to the starter and ground.

    3. I always use a wide open throttle start when mine is hot.

    4. Consider an alternator conversion to keep that 6V battery up all the time. They are easy to do and cost around $120.

    You can always convert to 12V but I found it was a lot cheaper to keep it 6V. Remember once you chew up a flywheel gear it's gone. And it forces me to keep the engine in perfect tune.
     
  6. 46mercury
    Joined: Dec 19, 2010
    Posts: 85

    46mercury
    Member
    from livonia MI

    By the way, that is one SWEET car.
     
  7. CutawayAl
    Joined: Aug 3, 2009
    Posts: 2,144

    CutawayAl
    Member
    from MI

    It is simple physics that 12v is better than 6v. But, a 6v system works fine when there are no problems. Whether or not you switch to 12v, find and correct the problem.
     
  8. R Pope
    Joined: Jan 23, 2006
    Posts: 3,309

    R Pope
    Member

    A good thing about 6v systems is, it forces you to keep your engine tuned up! They will start if everything is right. A new battery is the first thing you need, get the biggest one that will fit. Points, plugs, etc., will make a big diff, too.
     
  9. Bounder
    Joined: Oct 31, 2011
    Posts: 251

    Bounder
    Member

    I changed mine over to 12v and like it better. With the "one wire alternator" and doing away with the points, takes all the work out of "tune ups". Just saying. However you could get a 8v battery folks say they work well.
    By the way my Merc turns over about twice before it starts. Maybe I'm just lucky.
     
  10. Mogger
    Joined: Nov 28, 2006
    Posts: 20

    Mogger
    Member

    I would suggest new starter to battery cable. size 00. most people make the mistake of putting a 'new' starter cable on. and a new coil. An older hot coil wiring expands inside and takes a while to cool down again. and check all your ground straps. IMO nothing wrong with a well kept six volt system.
     
  11. psychotitan
    Joined: Feb 27, 2012
    Posts: 15

    psychotitan
    Member
    from LA

    Thank you for the info... I'll try a number of the recommendations.
     
  12. metalman
    Joined: Dec 30, 2006
    Posts: 3,297

    metalman
    Member

    I got 2 flatheads on 12 volt and one on 6. It's somewhat a pita to convert to 12, not hard, just a pain but I will be converting the 6 to 12 when I get the time. I hate not knowing if it'll start and not being able to jump it easy if it don't. Part of the problem is I'm having a hard time buying a decent 6v battery. Been thru 2 new ones, different brands but won't last more then 6 months. Sure they'll warrenty them but that don't help when your leaving cruise night and it won't start!
     
  13. mike hohnstein
    Joined: Dec 4, 2011
    Posts: 262

    mike hohnstein
    BANNED
    from wisconsin

    Saw a car recently that had a 8 volt battery, couldn't find the owner to discuss the implications, but it was a 4 cell battery.
     
  14. New cables and an 8 volt battery from your "good" jobber supplier will do the trick!
     
  15. Mike51Merc
    Joined: Dec 5, 2008
    Posts: 3,856

    Mike51Merc
    Member

    You've got a beautiful original looking car there. There's nothing wrong with a well maintained 6 volt system--- it's the 10 year old battery that let you down.
     
  16. 19Fordy
    Joined: May 17, 2003
    Posts: 8,016

    19Fordy
    Member

    If you convert to 8 volt battery you must readjust your regulator. Your 6 volt bulbs will burn out faster also. Perform the 6V maintenance ideas already suggested. Join your local AACA car club as the members will be knowledgable and able to help you.
     
  17. 8flat
    Joined: Apr 2, 2006
    Posts: 1,392

    8flat
    Member

    12v all the way. I went whole-hog on my F1, new wiring harness, alt., complete new ignition, min gear reduction starter, etc. It runs over fast and runs like a top.
     
  18. tommy
    Joined: Mar 3, 2001
    Posts: 14,757

    tommy
    Member Emeritus

    I see no advantage to staying with 6V. I'd clean all the connections even if it were converted to 12v. I did a tech article on converting a 6V generator to 12V. It's not a great deal of money. I added electronic ignition and my old flathead would start in less than one revolution. I can't stand a 1 wire alternator on a flathead. It looks like a pimple on Marilyn's nose. All my batteries are under the floor so looks is not a problem.

    Unless you are restoring a car for trophies I see no advantage of staying with 6V. That being said, I have used a 36 Ford for everyday transportation with good reliability. It's not really an either or situation but given a choice it's still a 12V decision for me.
     
  19. LSGUN
    Joined: May 26, 2007
    Posts: 1,353

    LSGUN
    Member
    from TX

    An 8v battery is just a bandaid and can cause more problems than it's worth.
     
  20. Just had that same conversation with myself, regarding my '40 truck. 6v or 12v? After inspecting the original wires, it was clear that they all were dry rotted and needed a total rewiring. Since it's way easier to find a 12v GM alternator, the choice was a bit easier for me to make. With you stating that you don't know **** about cars, it makes even more sense to convert it to 12v with a negative ground, to reduce any issues trying to jumpstart, etc.

    Here's the info that I began my conversion with: http://www.oldengine.org/unfaq/six12.htm
    I also used this thread to make my voltage reducers for my gauges: http://www.jalopyjournal.com/forum/showthread.php?t=448589
    Here's a page that tells how I used the stock push button and column switch in my wiring: http://streetrodder.net/?p=834

    The cool thing about having your 6v starter on a 12v system...you barely have to bump the start button to fire the thing up!
     
  21. Oh...nice car, by the way!!!
     
  22. psychotitan
    Joined: Feb 27, 2012
    Posts: 15

    psychotitan
    Member
    from LA

    I just remembered I had a good chunk of Amazon credit. Figured I'd pick up a Optima 6V battery after a number of posts I've read. Hoping this battery works with a positive ground system (My positive terminal currently grounds to the engine block and body). I'll also pick up a 00 size ground cable.

    Thanks everyone for the advice!
     
  23. dan c
    Joined: Jan 30, 2012
    Posts: 2,516

    dan c
    ALLIANCE MEMBER

    great looking car--the "snowballs" really set it off. judging by the trees in your pic, i'd guess your climate is warm enough for 6v. if memory serves, you can jumpstart from a 12v by clamping the 12v positive side jumper to the starter side of the solenoid on your car, then you touch the 12v negative jumper to the head and your starter will spin. shouldn't affect anything else since the juice only goes to the starter motor.
     
  24. converted to 12v, single wire alternator. no regrets
     
  25. need louvers ?
    Joined: Nov 20, 2008
    Posts: 12,903

    need louvers ?
    Member

    Go 12Volt, do not pass go, do not collect 200.00! Don't even fool with the 6volt stuff. I notice a large amount of the "keep the 6v guys" on this thread were from cooler temp regions where a car never has to start on a 100 degree day. I'm sure in L.A. your gasoline is a large part ethonol as it is here in Phoenix. The stuff boils off at about 190 degrees which means a longer cranking time on a hot day to refill the float bowls after the car has sat hot for a few minutes. Absolutely no fun with a six volt system. With twelve volts it's easy because the starter spins so much faster.
     
  26. 52RAM108
    Joined: May 5, 2010
    Posts: 120

    52RAM108
    Member
    from 76564

    the problem with 6V systems is that they are more vulnerable to voltage drops due to conductor corrosion. The main culprit is the battery cables, and the secondary culprit is corrosion resistance at the vehicle's frame.

    Original 6V cables should be in the 2/0 or 00 size to allow enough current to flow from the battery to the starter motor. The original cables may look okie dokie, but if ya peel off the sheathing, you'll see the copper strands black and cruddy, a sure sign of corrosion. With enough internal corrosion, the cable's internal resistance effectively reduces the amount of current that can pass through it, bogging down starter motors because they cannot draw enough current to spin the motor fast enough at startup.

    The problem with the original frame is that there is a cumulative effect of corrosion at each attaching point, be it crossmember rivets or bolt threads. When new, these machines sported nice shiny metal; but over time, each frame attaching point gets dirtier, which boosts electrical resistance. In effect, this makes the vehicle's electrical ground harder to pass voltage through. A trick I was told was to put small welds near rivet connections not for structural bracing but for electrical continuity.

    Another trick I was told was to run the grounding cable not to the frame but to one of the starter mounting bolts. This makes the starter directly connected to the battery, reducing any voltage drops from corrosion resistance. This may require a longer grounding cable, but the starter performance will pay for itself.

    Switching to 12V is an upgrade of convenience as then you can modernize any old car. The 6V systems are only as competent as the condition of their components. Imagine if you had all 12V parts, but they were decades old...they probably wouldn't work too good either. :cool:
     
  27. psychotitan
    Joined: Feb 27, 2012
    Posts: 15

    psychotitan
    Member
    from LA

    I see a 12V conversion very near in the future. I attempted to charge the old battery and after 6 hours, made 0 progress.We'll see if the newly purchased 2/0 cable and soon to receive Optima 6V battery make much of a difference. If it works, I'll keep the old system. If not, I most likely won't put too much more time into it and just pull the trigger and convert.

    Thanks again for all the posts.
     
  28. chopper cliff
    Joined: Aug 19, 2011
    Posts: 265

    chopper cliff
    Member
    from lodi ca

    8 volt is the cheapest way to go, regulater will compensate for the different voltage, however, if you want reliable service! If the bendex spring is good on the starter you will not damage the flywheel, it hits hard w/6volt starter and does not grind. I have been using this sysyem for over 35 yrs w/great success. Change all of the Bulbs in the system and instal a quality volt drop for the guages, and alternator works well and is easy to install on a flathead, use a 1 wire Delco unit w/ a Ford tractor pulley available at most Tisco and Ford tractor parts houses, about 10.00 bucks, fits on the alt with no problem, 6 volt wiring is already over kill cause of the volts and amps and will handel 12 volts w/ no problem, if your wiring is good. I have converted several cars for people over the years and have no problem, you will need a 12 volt coil and a resister for the points. Contact me if you are interested and I can give you step by step details on how to make it work. I did the first conversion 35 yrs ago, still do it and have no problems.. Good Luck! Cliff. p.s. don't cost that much!!!!!
     
  29. Do Good Jr.
    Joined: Feb 15, 2009
    Posts: 106

    Do Good Jr.
    Member
    from texas

    I recentlly finished switching to 12v and rewiring my '50 Ford Coupe. I had planned on keeping the original wire, but it was too far gone. I am using the 6v starter, solenoid and dash switches. I am running the Flathead with Pertronix ignition and coil. Changed all the bulbs and headlights. Also used voltage reducers for the factory gauges. I upgraded to a Powermaster Powergen ( one wire 75 amp alternator with look of generator). I have had no problems.
     

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