Pertronix used with Overdrive ?

[Deleted User]
[Deleted User]
edited November -1 in HUDSON
I am installing a pretronix ignitor system in my 50C8 with o/d(6V pos gnd), is there any issue with the overdrive kickdown that usually grounds out the points momentarily to disengege the OD. I don't want to put it in and the first time I kick it down and damage the ignitor unit.



Tom

Comments

  • 50C8DAN
    50C8DAN Senior Contributor
    Wow that is new! I tried about 5 years ago to get them to make an ignitor for the 8 and they wanted several hundred $$ for a one off.
  • Park_W
    Park_W Senior Contributor
    I talked with Pertronix engineers a few years ago on this point, and they assured me it would not harm the unit. And my friend's Pertronix-equipped Hornet, on which we were installing the OD, never had a problem with it.
  • bob ward
    bob ward Senior Contributor
    Your points only create a signal for the Pertronix to tell it to deliver a spark, there is no serious power passing through them to the Pertronix.



    If your points are grounded momentarily for the OD to operate, it just means the Pertronix is not receiving a signal, you won't be sending any nasty power spikes where they don't belong.
  • [Deleted User]
    [Deleted User]
    Bob you need to clarify what you mean here. The Pertronix unit replaces the points in your distributor. So there are no points anymore only the Ignitor module.
  • Richard E.
    Richard E. Senior Contributor
    I have been using Petronix on my '50C6 w/OD for a couple of years with no problems.
  • Jim Kilday
    Jim Kilday Expert Adviser
    There is an issue that will burn out the Pertronix unit. I know it is real because I burned out the first unit I installed.



    There needs to be a resistor in the wire to the coil. I'm sure I posted the problems here and a search would disclose that.



    The resistors are an odd size and hard to find. I may still have a record the place were I bought the resistor. It's in Chicago or a suburb.



    As I recall, Pertronix furnished a schematic to show how to wire it and the resistor's size. Ask them to explain it to you and send you the schematic.
  • Jim Kilday
    Jim Kilday Expert Adviser
    Here's the thread I was referring to--



    http://classiccar.com/index.php?option=com_jfusion&Itemid=62&jfile=showthread.php&t=15043&highlight=kilday
  • [Deleted User]
    [Deleted User]
    Thank's for the advice on the install & operation. This is a "new item" in their catalog and is a special order. Have been waiting 4 weeks so far and the place I ordered it through is getting impatient with pertronix's slow response time. Was told originally that it would take 2 weeks for a special order, hope it comes in soon.



    Tom.
  • [Deleted User]
    [Deleted User]
    I finally got my ignitor unit and installed it, seems to work ok. I called Pertronix about the OD wiring. The OD wire now needs to connect to the power side of the coil as the +(gnd) side is connected directly to chassis ground. Also needs a 7Ohm/5watt resistor between the OD wir & the coil(- power) terminal to prevent damage to the ignitor unit.



    Tom.
  • Park_W
    Park_W Senior Contributor
    Sounds like Pertronix has changed their mind about momentarily grounding their unit. But if I'm interpreting your description correctly, they're saying to use the OD "ignition grounding wire" to ground the powered side of the coil, but do it with a 70 ohm resistor between the hot side of the coil and the OD shorting wire. Can't believe that's the case, as it would have no effect on the ignition.



    It would make more sense if they said to connect the OD grounding wire to the sensor that replaces the points, and connect the Pertronix there also, but via the 70 ohm resistor. That way the points would be solidly grounded but the Pertronix unit would not (because of the resistor between the ground and the unit.
  • [Deleted User]
    [Deleted User]
    Hi Park,

    The wiring on my ignitor is as follows. The original ignition power to the coil(- side) is connected to the black/white wire from the ignitor unit only, not the coil, the black wire from the ignitor is connected to the the (-) coil terminal and the (+) coil terminal is directly to B+/chassis ground. So, the O/D cutout circuit has to be tied to the (-) coil terminal with a 7 ohm/5 watt resistor( not 70 ohm) in order to momentarily kill the ignition and not damage the ignitor.

    I'm not sure if Pertronix has changed the wiring lately or just for the 8 cylinder ignitor.



    Tom Brintnall
  • 7XPacemaker
    7XPacemaker Senior Contributor
    I have used pertronix units on two different cars and they don't impress me much- but to each their own. The spark didn't seem any hotter than the points. I threw both of them out and ran an electonic distributor. Both engines were high performance. There is no substitute for an electronic ignition if that is your fancy. I know that there are no alternatives out there for the 8 cylinders though. Personally, I think you are better off keeping what you have or at the very least, keep a spare set of points in the trunk so that you can switch them over if need be. I have seen many sets of these fail.
  • Park_W
    Park_W Senior Contributor
    Tom, after seeing the diagram and remembering that the entire igniter module is at/in the distributor, I can see that it could work OK. It's a little surprising that the unit could be damaged with a direct grounding of the coil's neg. terminal, but not when done through a 7 ohm resistor. But they likely know what they're doing.
  • jjbubaboy
    jjbubaboy Senior Contributor
    So, if a guy also has a tach to hook up which terminal on the coil does that wire go to?

    It would seem that with points it would go to the wire to the distributor but now with that terminal grounded to chassis that wouldnt work, or would it?



    Jeff
  • [Deleted User]
    [Deleted User]
    ET8conv wrote:
    I am installing a pretronix ignitor system in my 50C8 with o/d(6V pos gnd), is there any issue with the overdrive kickdown that usually grounds out the points momentarily to disengege the OD. I don't want to put it in and the first time I kick it down and damage the ignitor unit.

    Tom

    Today I spoke with the fellow who designed the 8 cylinder module. He provided me with information on who to speak with about impact of using the Hudson overdrive with the new ignitor. I am currently traveling so my contact will be sometime next week. When I have pertinent information to share, I will post here. :)
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