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To Pertronix, Or Not Pertronix...that Is The Question

Discussion in 'Early CJ5 and CJ6 Tech' started by TonyM, Oct 25, 2019.

  1. mickeykelley

    mickeykelley Well-Known Member

    Sorry, didn't know.
     
  2. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    No problem. It was funny. :beer:
     
  3. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Depends on your definitions. Electronic ignition is more reliable if you include the expected failure of points due to wear every 25,000 (?) miles. The MTBF for a Pertronix module is way longer than that. I'd also point out, 'crib death' is a well-known phenomenon for electronics - failure is very much more likely at the beginning of life than any other time.

    Points are, no doubt, more accessible. You could carry a spare Pertronix module if you were worried. I'd think a field repair would be really easy, if you had a spare module.
     
    fhoehle likes this.
  4. TonyM

    TonyM Member 2023 Sponsor 2022 Sponsor

    I always carried extra points, condenser, cap and rotor and plug wires anyway. I figured I'd still do that as they'll all still be on the breaker plate that I'm removing, or carry an extra Pertronix. I've been pretty much a "keep it stock" guy for the 25 years I've had jeeps ('51 3A, '52 M38 and now a '56 CJ5) but I've reached the breaking point - pun intended - with the points going bad from lack of use. I don't get to use my jeep as often as I'd like (sometimes she'll sit for 6-8 weeks, though I do try to at least start it up and let it run for a bit every 2 weeks or so). When I do get the time to enjoy it I want to simply turn the key, engage the toe starter button and enjoy the ride. I'm hoping that the Pertronix will allow for this. If not, back to points...
     
  5. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    So, I pull a piece of emery paper between them, takes about 20 seconds.
     
    fhoehle likes this.
  6. colojeepguy

    colojeepguy Colorado Springs

    Somehow, this seems familiar....:lol:
     
    PeteL likes this.
  7. mickeykelley

    mickeykelley Well-Known Member

    That's actually not a bad idea. Much easier and faster field repair and not that expensive. Going to give serious consideration to put on my list as a precaution.
     
  8. Glenn

    Glenn Kinda grumpy old man Staff Member

    Let's throw this thought out there. Normally with a points igniton system the condensor is the only thing that fails, and as we have discussed it used to be rare for that to occur. Nowadays the chance of walking into a parts store and leaving with a good condensor seems kind of iffy. This makes a Pertronix seem desirable for sure. However known failures, defective units sent and not working from the beginning makes me go hmmmmm! I'd bet they had much better quality years ago.
     
  9. Stano316

    Stano316 Member

    I heard the new corvettes have points...
     
  10. mickeykelley

    mickeykelley Well-Known Member

    Surely not.
     
    Stano316 likes this.
  11. Cowboyjeeper

    Cowboyjeeper Member

    The treehuggers would never allow that lol computer would lose its mind haha
     
    Stano316 likes this.
  12. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Eight sets of points for all eight coils?
     
  13. ROBERT H SWARTOUT

    ROBERT H SWARTOUT New Member

    Dwell is the measurement the time points are closed. So a dual point system can build higher spark by splitting the time in half.. if I have that right. might have to dig out my old college notes. So a old school dual point mallory was used for 60s and 70s muscle cars with the big ol yellow coil. I find plug wires make a big difference on the 74 304 v8 AMC. The heads flow as good as a set of 202s with the dogleg ports
    Schavenged by a nice set of long tube headers and a set of long purple hornies pointed out the side not down for dust.
     
  14. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    My misty teenage conception of the dual points benefit was that at very high rpm, each set only had to operate half as often - thus reducing bounce, float, etc.

    No?
     
  15. mickeykelley

    mickeykelley Well-Known Member

    That was my understanding.
     
  16. Lockman

    Lockman OK.....Now I Get It . 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Yes....... Exactly what it was for. Remember Mallory ?
     
  17. Walt Couch

    Walt Couch sidehill Cordele, Ga. 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Not really. The dual points open and close the same number of times per rotation but are placed about 9 rotational degrees apart. This increases dwell time for sure but best reason for dual points was to decrease maintenance on dist and increase performance.
     
  18. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Come to think of it, I believe that is how the OEM distributor works in my 1934 flathead Ford V8. One set begins the dwell, the other set ends it. (?) It allows each action to be timed independently.

    What is old is new(ish)?
     
    Last edited: May 27, 2020
  19. Walt Couch

    Walt Couch sidehill Cordele, Ga. 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Yes that is it.
     
  20. Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    The purpose of dual points seems to be that you can extend the amount of time that the points are closed as compared to a regular setup, allowing current applied to the primary more time to build up the energy (i.e. "saturate") that will become a spark when the points open.

    Note that this really only helps at high rpms as at lower speeds a typical coil has plenty of time to saturate anyhow.

    Also the extra spark is really only useful on high compression engines.

    This is why Corvettes came with dual point distributors & Massey-Fergussons did not.