Register now to get rid of these ads!

Will a generator fire a electronic ignition?

Discussion in 'The Hokey Ass Message Board' started by tiredford, Mar 22, 2013.

  1. tiredford
    Joined: Apr 6, 2009
    Posts: 488

    from Mo.

    I have a early small block ford with elec ign and a small altenator. Trying to make it look way older, I would like to install a gen. This is a weekend cruiser with no assesories what so ever. Have you done that?
  2. I have a generator on my avatar and I am using a Pertronix set-up in my Mallory distributor and it works fine. The only electrical items I have otherwise is an electric fuel pump.
  3. Ignition doesnt care how its electric is made, Switching back to generator also means hooking up a regulator and if you currently have a single wire alternator then your gonna be doing some rewireing..
    Boneyard51 likes this.
  4. Yes but check the voltage at the lead wire that used to fire your coil and see that you are getting a full 12 INPUT voltage there.....
    Boneyard51 likes this.
    Register now to get rid of these ads!

  5. tommy
    Joined: Mar 3, 2001
    Posts: 14,758

    Member Emeritus

    A generator does not "fire" any ignition it merely recharges the battery. The battery fires the ign. Many aftermarket electronic ign. systems do not recommend a generator (I'm not sure why) therefore they may not honor a warranty. I'm running Chrysler electronic conversions on my old hot rods and the batteries are charged by generators. My systems don't have a warranty and have worked just fine for 15 years.
    kidcampbell71 and Boneyard51 like this.
  6. Mike51Merc
    Joined: Dec 5, 2008
    Posts: 3,830


    It's really the battery that supplies the voltage. The generator or alternator is only there to replenish the battery.

    That being said, generators are sometimes known for voltage spikes and magnetic interference that have been rumored to disturb electronic ignition systems.
    Boneyard51 likes this.
  7. scrap metal 48
    Joined: Sep 6, 2009
    Posts: 5,929

    scrap metal 48

    Excellent question and I've learned something...
    Boneyard51 likes this.
    Joined: Jun 15, 2006
    Posts: 3,384


    I guess it should be said that a "properly operating" generator will run a electronic ignition.
    Like the others have stated the generator needs to be putting out a clean steady power supply to keep the battery properly charged.
    I ran a generator on my Model A with gmc power. It ran great around town but i noticed that when on the road at night ( using headlamps) that the supply voltage to the ignition sometimes would drop to 8-9 volts etc. ( causing the engine to run a little different) My new headlamps were drawing approx the max output of the generator.

    After a couple summers i switched to a small case jap alternator ( painted black and mounted low) to maintain the juice i needed all the time...
  9. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    Rewiring is barely an issue, assuming here '56-62 type Ford generator.
    The hot wire from alternator would just be shortened and hooked to the BAT terminal on regulator. The other wiring is then a very simple set that does not affect any other wires:
    Find ARM, FLD, and GRD studs on gen, run wires to same things on regulator...ground wire goes to baseplate of the regulator. 3 terminated wires, wrap'em. done.
    kidcampbell71 and Boneyard51 like this.
  10. These two pretty much summed up about how we at PerTronix feel about Generators with our Ignitors - If everything is working correctly, no problem.
    Boneyard51 likes this.
  11. Could not say it any better myself. As long as the generator is meeting the required electricl demand, it should be fine. Especially daytime. At night with all your lights and then throw in cold so you are running heater fan, it may be close to the limit.
    Boneyard51 likes this.
  12. I don't know what the power draw for the stock Ford electronic is or even the petronix. I do knpw that a mallory unilite only draws 9 volts and 1 amp per thousand RPM. I would think that a genny with a properly adjusted voltage regulator would run the mallory just fine.
    Boneyard51 likes this.
  13. Some electronic ignition systems were a little picky about having a consistent minimum voltage. Chrysler had an upgrade kit years ago that required adding an electronic voltage regulator to vehicles that weren't so equipped.

    As already mentioned, it seemed like a smooth, clean output was practically as important as a minimun voltage.
  14. fsae0607
    Joined: Apr 3, 2012
    Posts: 871


    I have my Pertronix's main power coming from the "BAT" terminal on the voltage regulator and I have a generator on my '61 GMC. Works great! :cool:
  15. One time I installed a new HEI distributor in a 70 Chevy pickup I was fixing that had been built with a point distributor.

    It was installed and I hooked up the old wire that had gone to the old coil[resistor wire I assumed].
    It started up and ran seemingly fine for a week or two,locally before I took it on a [200 mile] trip.
    That is where I noticed that I had a problem.
    as I pulled in at the place on the trip's end, the motor just died as I idled at a stop light.

    After looking it over it was discovered that the aforementioned power wire had got hot enough to actually burn itself into completely.

    I don't know if it was too much draw for the resistor wire or if I had another issue ,but it did happen,so food for thought.......anyone had this happen?
  16. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    HEI runs on full 14 volts, has a large (10gauge?) feed wire...don't know amp requirement, but it will not be happy running on the resistor! That would be a resistor wire on any points Chevy.
    Boneyard51 likes this.
  17. They don't "Draw" voltage at all. Mallory is pretty specific about wanting 11-12v to the red side of the Unilte, in other words hooking it it the input side of the ball sat resistor, the output side is only for the coil.

    As far as amperage draw goes, the Ignitor is basically just a switch so the draw really comes from the Coil and they will have more current draw at low RPM and less at higher RPM because of the inductance of the coil.

    The Ignitor II & III have our patented adaptive dwell, and the adaptive dwell means they limit the current to 6.2 and 6.9 amps respectively. That is to say, they limit the per-spark current. Each time a spark event occurs, they turn on the coil just long enough to let it get up to 6.2A. Since spark events happen less often at low speed, the average current in an Ignitor II or III system is lower at low RPM and higher at high RPM.

    The Mallroy is going to be closer to what our Original Ignitor does, but I would think with a few milliamps for the light in the optispark.
    Boneyard51 and vinfab like this.
  18. Yea draw was a poor choice of words. The literature that I have here that I have had for a long time says that the mallory ignition only needs 9 volts to run and 1 amp per 1000 RPM. But even at 11-12 volts that should never be a problem, even a genny that is going to keep your 12 volt battery charged is going to produce 12 volts minimum.

    The ignition should not be run off of the genny or the alt anyway, a battery makes a good buffer against a power surge.

    Riddle me this Don, I know it is off topic but it just popped into my head. A car runs off of D.C. and an alternator produces A.C. where does it change from A.C. to D.C. ? Not a trick question just a question.
  19. AllSteel36
    Joined: Jul 20, 2009
    Posts: 562

    from California

    The diode circuit...believe it's called a bridge diaode setup? inside the Alt.

    To the OP, might be a conversion available with a generator case to an the Flathead guys use to "keep the look" of the Generator.
  20. In common language, the alternator produces AC current as the the rotor spins past three stationary stator windings, surrounding a fixed iron core that makes up the stator. This is referred to as a three-phase current. The coil windings are evenly spaced at intervals of 120 degrees around the iron shaft. The alternating magnetic field from the rotor produces a subsequent alternating current in the stator. This AC current is fed through stator leads into a connecting set of diodes. Two diodes connect to each stator lead to regulate the current. The diodes are used to essentially block and direct the current. Since the car battery and systems need DC current, the diodes become a one-way valve that will only allow current to pass in the same direction.
    Once the power is converted to DC it has to be regulated to not produce too little or too much voltage. There are two types of regulators commonly used; grounded regulators and grounded fields. Grounded regulators control how much flow there is on the negative side going to the battery, while grounded field control's how much power is going to the positive side. I don't think there is really any advantage of one over the other, just two ways to get there.

    It can get more technically involved with single phase and three phase design alternators and whether the windings are Dye style or Wye style, but that is getting deeper than we really need to know for this discussion.
    Boneyard51 likes this.
  21. Dane
    Joined: May 6, 2010
    Posts: 1,353

    from Soquel, CA

    Some of the electronic ignitions don't like noise in the 12 volt supply. The old point type regulators by switching on and off generate noise spikes when the contacts open. If it runs good you probably don't need one. But there's a "60's period correct" type filter on eGag "Generator Noise Filter 6 12 24 volt Generator Archer Noise Filter"
    Boneyard51 likes this.
  22. 41 C28
    Joined: Dec 17, 2005
    Posts: 1,770

    41 C28

    Interesting information that I'll put in the bank.
  23. HRK-hotrods
    Joined: Sep 26, 2007
    Posts: 922


  24. I replaced a small alternator with a later 12 volt generator and a new regulator so my car would look older and the generator was much better :):)than the alternator when it came to power output and I could easily adjust it to any setting I wanted. :):)
  25. Ive converted my 66 GMc to HEI. hooked it to the resistance wire. and Its beem that way for 6 years no problem. Some of my farn tractors I converted to electronic IGN. and they have generators works ok if it has a good battery.
    Boneyard51 and Truckdoctor Andy like this.
  26. MeanGene427
    Joined: Dec 15, 2010
    Posts: 1,437

    from Napa

    I have kind of a strange duck that relates to this thread, it's an older Clark 4K forklift that I grabbed because I needed one with fat tires in the winter, it's in pretty good shape and the price was right. Came from a winery, where it had been a backup/ busy time rig for years, then they bought a few new ones again, so it sat. This winery's shop has a rep for doing things right and attention to detail, and it showed on this one. It has a Continental flathead with some interesting features, I thought it wasn't charging as it was showing 12.25 volts, so first thought put a one-wire on it. Not so easy, it has a triple belt setup, and also has a separate power steering system with its own pump, which drives off the end of the generator- not something I want to spend that much effort on to modify. So while I'm in there, I notice a ballast resistor on the bulkhead, with no wires attached. So I look at the distributor, and it has a Pertronix kit, nicely installed. So I do the "motor" test on the genny, motors just fine, so head for the regulator, replacement Filko in pretty good shape, and non- adjustable, and with a little testing, is actually working, after starting, comes up from high 11's to 12.25 every time and stays there, lights on, whatever. It's on propane, battery holds a charge, runs great, old flathead starts just fine at 12.25 and the Pertronix seems very happy. Closed the hood and walked away. Used it yesterday, started right up, ran like a watch, didn't open the hood or touch the voltmeter lol...
    Boneyard51 likes this.
  27. Boneyard51
    Joined: Dec 10, 2017
    Posts: 4,018


    Might want to check your voltmeter! My Fluke was way off last time I tried to use it!

  28. MeanGene427
    Joined: Dec 15, 2010
    Posts: 1,437

    from Napa

    First thing I tried, all three read the same, and cross-checked on other batteries and the Exploder. Was hoping it was an adjustable regulator, but no. Since it all works and starts good, gonna use the if it ain't broke, don't fix it deal
    Boneyard51 likes this.
  29. Truck64
    Joined: Oct 18, 2015
    Posts: 4,056

    from Ioway

    Generators have a somewhat higher charging voltage set point than alternators, not sure why. From 1/2 to almost 1 volt higher on average than an alternator, depending on the ambient temperature.

    The voltage specifications in the manuals were produced using analog equipment, something to be kept in mind when looking over obsolete charging systems. But any battery wants approx. 2 volts over and above its resting voltage to reach a full recharge, and even more in cold temperatures.

    The battery strictly speaking has one purpose - for starting the engine. All of the voltage and current for lights, ignition, and accessories is provided by the alternator or generator, not the battery.

    The battery does have an important role in that it acts as a filter or "flywheel", to absorb voltage spikes or smooth out sags. This is why removing a battery terminal while engine is running is not a very good practice for troubleshooting in late model vehicles. Maybe you can get away with it, but it's not healthy.

    I've heard some people claim that the Pertronix Ignitor doesn't play well with a generator, but it's never skipped a beat in 20 years for me.
    Boneyard51 likes this.
  30. Atwater Mike
    Joined: May 31, 2002
    Posts: 10,086

    Atwater Mike

    My Snap-On digital meter supposedly had a problem when drunk brother used it...
    He said it wouldn't display voltage, when he returned it I tested it on various scales. Every test was conclusive, no faults found.
    Must have been a 'fluke'...:eek:

Share This Page

Register now to get rid of these ads!


Copyright © 1995-2020 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.