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Generators vs Alternators

Discussion in 'The Hokey Ass Message Board' started by Hooligan36, Oct 25, 2008.

  1. Hooligan36
    Joined: Jul 27, 2008
    Posts: 129


    Ok, again... I need some help. I may be off in left field here.

    I'm building an open wheeled "t-bucket type" rod. I have a SB Chev that I bought that has 0 miles that I will be using. Along with the motor I also was given a new chrome 1 wire alternator. Now my original idea was to use low mount brackets to keep it out of the way.

    Now.... generators are in territory I have never ventured into. Whats the deal with them? Are they reliable, not good for any use these days, or anything I should know? Reason I ask is I have always liked the way they look, they have that "old" look.

    Just curious, figured you guys could shed some light for me. Any pics of anyone still running them?
  2. Can only speak from experience put i have never had any problem with the ones i have had, and I still run one on my falcon. They are not so great when you have accessories that draw heaps of current like a huge stereo and the like, but i can't imagine that being an issue on a t-bucket.
  3. I used to go through brushes on them like mad. Other than that, no real issues.
  4. str8axleford
    Joined: Oct 14, 2007
    Posts: 92


    The alternator creates a current in AC (alternating current) and it is converted to DC (Direct Current) via the diode trio inside it. A diode only lets elecricity flow one way though it. With alternating current (like in your home) the current goes back and forth. The battery in your car is like a capacitor in a way. It dampens the current from surging electrical components. Hence why on most brand newer vehicles it wont even let you start it without a battery in it because it will fry the ecu.

    In Direct current, the electricity flow is one way. Generators are ok to run the car on, but cant keep up with added electrical draw (stereos n such)

    If your going to keep it basic, you can run a generator and be fine. Just have to make sure there aren't any shorts in your rotor and your brushes are good. In a sense they are more reliable than an alternator, because those are the only 2 that can go bad. Unless you break a magnet of course.

  5. Generators were used for decades before alternators became the choice of car manufacturers. Cadillacs, Lincolns etc ran power windows, radios, electric seats, even air conditioning with generators, so I dont see any problem.
  6. All good answers. The one thing not mentioned, an alternator charges at all rpm's. A generator charges less at idle, more as the rpm's increase. Turn on all your accessories at night with a generator and rev the engine. You'll see the difference.-MIKE
  7. skwurl
    Joined: Aug 25, 2008
    Posts: 1,620


    We're running a generator on A comet . It has air ride on it. No problems yet.
  8. Also, be sure you got a good voltage regulater. They can stick and sling the solder out of your generator. Just sayin' don't scrimp there.
  9. Ole don
    Joined: Dec 16, 2005
    Posts: 2,915

    Ole don

    On a T bucket, a correctly rebuilt generator should last nearly forever. Good bearings, a clean commutator, the correct size wires, and a regulator that is matched to the generator or will hold down the current to what it wants to put out. Find out how to polarize your type before you put power to it. I have run one for several years with no problems.
  10. Dirty2
    Joined: Jun 13, 2004
    Posts: 8,903


    Run the alternator and send me the generator .
  11. 51ChevPU
    Joined: Jan 27, 2006
    Posts: 1,076

    from Arizona

    Here's one I'm trying to figure out. I'm running an old 52 chrysler hemi 331. I would like to run the generator I have , but its only 6 volt. All I'm running is front and rear lights , dome and license plate light. That's it......

    Now the problem is, I planned to switch over to the mopar electronic ignition. I already have the different intermediate shaft installed for the different dizzy. That system ran on an alternator.

    Golden question is, can I remove the alternator and run the 6 volt generator with this system. I was hoping to run the generator to keep the engine looking stock.

    What problems will I encounter ,if any? Thanks
  12. tommy
    Joined: Mar 3, 2001
    Posts: 14,757

    Member Emeritus

    Get a Motors Manual from the late 50s or early 60s. (Ebay) Everything you ever need to know about generators is in there. There are some slight differences between GM and Ford. Figure out which one you have and the book will have your answers.

    Generators are easy to tune up at home. The book will help. Polish the commutator and install new brushes. The voltage regulator can be a confusing looking box of coils and contacts but the book will have the test procedures to accurately determine where any problem might be. I always buy a new VR for any new build and tune up the generator.

    Personally I've had more trouble with alternators than with the generators on my old cars over the years. I have to look it up every time I need to polarize a generator because Ford and GM are done differently. That's what the books were printed for.
  13. junkyardjeff
    Joined: Jul 23, 2005
    Posts: 8,061


    I am thinking about going back to a generator on my 37 chevy p/u for a period correct look,I was told to get one from a larger car and years ago I ran them without too many problems but I had a 53 olds with underdash air and with it on the lights got dim at traffic lights but for your application it should work fine.
  14. Im an advocate for the gm one wire alternator. But i build cars with hoods. When i build my coupe i will be running a generator to be period correct.
  15. tommy
    Joined: Mar 3, 2001
    Posts: 14,757

    Member Emeritus

    I converted my Mallory dist. with the Chrysler electronic ignition parts. It ran great with a 6V generator that was converted to 12V. I had no problems powering the Chrysler ignition with a generator. Just my experience. Some say that generators put out spikes that blow the module. I had no such problem with mine.

    Personally, I'd get a 12V generator from any Mopar after they changed to 12Vs. (I don't know what year they changed) Get the VR to match. I used a generator off of a 6cyl Fairlane on my flathead.
  16. gas pumper
    Joined: Aug 13, 2007
    Posts: 2,956

    gas pumper

    I'm not running any generators now, but have a lot of experiance with them.

    I have run a 6V Delco on 12 volts. The regulator controls the voltage and amperage. Use a 12V regulator. At 12 volts you will be producing ~1/2 the amps that 6V was (OHM's law). You could also just change the armature to a 12V one. The field coils would be fine.

    Read the book about setting the neutral of the brush holders, that gives you the least amount of sparking and increases the brush life and makes the generator more efficient at lower speeds.

    Generators, as they were used, didn't put out at idle, but then idle speeds were 4-500 rpm. If you are idleing at 800 you might be fine. But this is only important if you anticipate sitting in traffic.

    They used to call me sparky.;)
    Last edited: Oct 25, 2008
  17. Hooligan36
    Joined: Jul 27, 2008
    Posts: 129


    man, I appreciate all the feedback. From the sounds of it I should be fine. I only have headlights, 1 taillight, and 2 small gauge lights. I see them all over the net.. is there a certain style I should look for when buying one such as the car it came from?
  18. tommy
    Joined: Mar 3, 2001
    Posts: 14,757

    Member Emeritus

    It really doesn't matter what car or truck it comes from. I'd try to buy one from someone that knows for certain what it came off of so that getting the correct VR will not be a problem. Picking one out of a pile in a junk yard may make it hard to exactly identify. Get one from someone that put it under their bench when they went the one wire route. Check with all of your buddies. They might have a parts car with a generator behind the garage. Then you know exactly what you are dealing with. It just makes life easier.

    Sometimes you can find old stock factory rebuilt units on Ebay. As long as they have the catalog to identify what it fits then you can get the VR to match that application.
  19. Torkwrench
    Joined: Jan 28, 2005
    Posts: 2,527


    Haven't had many problems with generators, except one thing.....They tend to blow up when you are shifting at 7000 RPM. :eek::D:cool:
  20. WW II was won with generators....
  21. Butcher Boy
    Joined: Aug 6, 2008
    Posts: 303

    Butcher Boy

    Just a thought........ take your generator and have alternator guts put in it. I see this done a lot on period cars that want what an alternator has to offer.
  22. Jimv
    Joined: Dec 5, 2001
    Posts: 2,924


    WWIII was prevented with alternators!!lol
    choose what you want but rememeber theres a reason why they don't use them anymore.
    i run a alt on my T, just put it on a lower bracket & its one less thing to worry about.But i drive the shit outta my car and i'm more concerned about getting home then looking "period correct".Besides a alt , small disk & a B&M dual gate shifter, brakes my car looks OK.
  23. Flat Ernie
    Joined: Jun 5, 2002
    Posts: 8,406

    Flat Ernie
    Tech Editor

    Generators & mechanical V/Rs will cause big spikes - electronic V/Rs miminize this a great deal. I think a lot has to do with the sensitivity of the module. Unilite modules are infamous for being burned up by looking at the wrong (although I've never had these issues with them)

    OK, Sparky, I think you've got that backwards. Ohms law is I=V/R, so dividing 12 by the total circuit resistance will always equal a larger I than dividing it by 6.

    Charging RPM is dictated primarily by pulley ratios. You can set up pullies to charge at idle for both alternator & has little to do with the design of the system.

    I've seen a few of these units fail. Alternators generate more heat than generators do & cooping them up inside a generator case makes it challenging to cool them.

    Here's a tidbit for you - a generator will normally recharge a completely dead battery whereas an alternator will's gotta have the feedback from the battery (excitation voltage vs magnetism).

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