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Technical Running a Mag on the street or an Imitation

Discussion in 'Traditional Hot Rods' started by FNG, Sep 14, 2020.

  1. dreracecar
    Joined: Aug 27, 2009
    Posts: 3,476

    dreracecar
    Member
    from so-cal

    Thats just what the kit is, plus it provides the wiring diagram for those that need some help [​IMG]
     
    Tman and bchctybob like this.
  2. bobkatrods
    Joined: Sep 22, 2008
    Posts: 755

    bobkatrods
    Member
    from aledo tx

    Probably why Airlines require two pilots in case one goes dead
     
    Roothawg likes this.
  3. Roothawg
    Joined: Mar 14, 2001
    Posts: 24,522

    Roothawg
    Member

    Going dead can be an issue.
     
  4. Beanscoot
    Joined: May 14, 2008
    Posts: 3,053

    Beanscoot
    Member

    If mileage is of any consideration, vacuum advance is necessary, and I don't know of any magnetos that had that feature.
     
  5. Harv
    Joined: Jan 16, 2008
    Posts: 974

    Harv
    Member
    from Sydney

    I swear, there were only two in cupboard when I last checked... they breed like mice.:D

    magnetos.jpg

    All have since been refurbished and converted to suit GM Holden's grey motor (inline 6, 1948-1963... Aussie version of the stovebolt 6).

    Only one is an eight cylinder... it's still asleep in the cupboard.

    And yep, even the dead ones bite. Spin them up with your fingers, and you'll soon do the Scintilla Shuffle.

    Cheers,
    Harv
     
  6. Bob Lowry
    Joined: Jan 19, 2020
    Posts: 1,488

    Bob Lowry

    You are absolutely correct. First mini-bike at 12yrs old. Learned all about magneto spark, and proper way to kill it.
     
  7. Roothawg
    Joined: Mar 14, 2001
    Posts: 24,522

    Roothawg
    Member

    So explain the difference between the OAC and the OXC mags.

    I found my answer:

    Q. What is the difference between the OAC Vertex Magneto and an OXC Vertex Magneto?

    A.
    The OAC competition model is a self-contained unit and has an internal coil. Amperage for the OAC = 1.3 AMP. The OXC Super Competition model has an external coil and is used for more high output applications. Amperage for the OXC = 2 AMP. It is used for maximum voltage output with a long duration spark and has been designed for engines using superchargers, exotic fuels and high compression engines.
     
    Last edited: Sep 17, 2020
  8. Harv
    Joined: Jan 16, 2008
    Posts: 974

    Harv
    Member
    from Sydney

    Interesting. The last four Vertex magnetos I had done up (old ones, as per the photos above, all internal coils) had the coils removed and replaced with new units. Nothing fancy. They pull 1.9 - 2.5A. The rebuilder offered an external coil conversion which would pull ~5A. Not bad for 1960's kit :)

    Cheers,
    Harv
     
  9. 51box
    Joined: Aug 31, 2005
    Posts: 1,099

    51box
    Member
    from MA

    I would recommend utilizing a separate kill switch for the mag, it has a few benefits that I’ve used multiple times.
     
  10. Bonehead II
    Joined: Apr 18, 2005
    Posts: 437

    Bonehead II
    Member

     
  11. Ned Ludd
    Joined: May 15, 2009
    Posts: 5,025

    Ned Ludd
    Member

    If centrifugal advance is possible, it shouldn't be impossible to rig vacuum in some way. You could even be creative about locating the diaphragm canister.
     
  12. 2OLD2FAST
    Joined: Feb 3, 2010
    Posts: 5,215

    2OLD2FAST
    Member
    from illinois

    For the sake of discussion ; I was told by Mallory tech 20 years ago that the mileage gain with vacuum advance was in the neighborhood of 10%+ - . For our cars , that's generally less than 2 mpg . Given the miles mist of our cars are driven , that savings amounts to a pretty trivial amount of money . IMO , hardly worth pursuing , or getting too concerned about . What say you ?
     
    Besty34 likes this.
  13. jimmy six
    Joined: Mar 21, 2006
    Posts: 14,795

    jimmy six
    ALLIANCE MEMBER

    18 years ago we had Joe Hunt hop up a 1amp
    Mag to 5 by the magnets and an external coil. I still remember how much better GMC 6 ran. I still have 2-3 extra OXC coils.
     
  14. lippy
    Joined: Sep 27, 2006
    Posts: 6,825

    lippy
    Member
    from Ks

    When you go all out on a vertex hopup you really need the big cap to prevent crossfiring. Lippy
     
  15. Harv
    Joined: Jan 16, 2008
    Posts: 974

    Harv
    Member
    from Sydney

    G'day Lippy,

    I've not heard of a "big" Vertex cap before. I've seen the various coloured caps (see summary attached), though the design of them is all pretty similar.

    I've also seen the close-interference suppression caps. In this case the magneto was screened with a special metal hood and screened (braided) spark plug leads. This was referred to as “radio screening type LRO”.

    Do you have any details or info on the big caps please?

    Cheers,
    Harv
     

    Attached Files:

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  16. jimmy six
    Joined: Mar 21, 2006
    Posts: 14,795

    jimmy six
    ALLIANCE MEMBER

    A big cap is done using Ford stock parts from a HEI type ignition for their 6 Cylinder. The adapter screws onto the mag and the cap clips on to the adapter. The rotor is the stock Ford. Joe Hunt did this on the mag we used in Joe Fontana’s 12 port GMC 6. They were light gray. Sorry no photos showing this.
    A Cardone 842669 for a 1975 E-100 van 300” 6 on Rock Auto will show the 6 cyl cap. An 8 cyl cap is available; but you can see the adapter.
     
    Last edited: Sep 28, 2020
  17. Harv
    Joined: Jan 16, 2008
    Posts: 974

    Harv
    Member
    from Sydney

    Many thanks Jimmy Six - appreciated. If I've got it right, you purchase a full Cardone 84-2669 dizzy, as per below: Cardone distributor.png You keep the cap and adaptor (labelled above) and the rotor button, but throw out the rest of the assembly. The adaptor mounts to the Vertex body using two of the mounting screws, circled in red above. Have I got this right? Anyone know if there is any additional machining involved, or if it is a bolt-up swap?

    Cheers,
    Harv
     
  18. 2OLD2FAST
    Joined: Feb 3, 2010
    Posts: 5,215

    2OLD2FAST
    Member
    from illinois

    Being plastic & a consumable , I'd guess that cap & adaptor are available separately ...
    Edit ,86 - 93 mustang 5.0 ??
     
    Last edited: Sep 29, 2020
    jimmy six likes this.
  19. Harv
    Joined: Jan 16, 2008
    Posts: 974

    Harv
    Member
    from Sydney

    I hope so... I'd really like to give the big cap modification a try, and any way to make it cheaper would be good. I tried Googling through the Cardone website, but could not find the cap/rotor/adaptor separate. Cardone is not seen to often Down Under, so harder to rock up to an autoparts store and ask for their help. Anyone better at Googling know what the part numbers might be please?

    Cheers,
    Harv
     
  20. jimmy six
    Joined: Mar 21, 2006
    Posts: 14,795

    jimmy six
    ALLIANCE MEMBER

    They are; I just Don’t know the Ford part numbers. I’m sure Standard and others make them.
     
  21. Just saw this thread and will jump in and out.
    In the mid '70s I commuted 50 miles a day for at least 2 years in a
    1957 Jaguar Mk I sedan running a Vertex Mag and Isky E-2 cams.
    Never touched it. It was solid as a rock up to 6000 RPM.
    Never even thought about a problem
    Just my info.
     
    Cliff Ramsdell likes this.
  22. 19Eddy30
    Joined: Mar 27, 2011
    Posts: 2,314

    19Eddy30
    Member
    from VA

    I have ran Vertex & Mallory internal and external coil's on street & Full race with 30 psi of boost , No issues,
    Most that try a Mag will not know how to start a engine properly.
     
  23. Harv
    Joined: Jan 16, 2008
    Posts: 974

    Harv
    Member
    from Sydney

    G'day 19Eddy30,

    Most cars have some quirks for starting - richer, leaner etc, especially if they are fitted with old mechanical choke kicks/dashpots etc. The one magneto starting quirk I know of relates to fixed timing. If the advance weights have been removed (or were never fitted), the engine needs quite a bit of fixed timing to compensate. Lots of timing advance at low speed can make them painful to start (on a bad day, the poor thing can try to run backwards like an old kero tractor). To help starting, the maggie switch is left on (maggie grounded) until the engine is up to full cranking speed, where tolerance for more advance is higher. The switch is then turned off (maggie not grounded) and the engine fires.

    Any other magneto starting tricks to share?

    Cheers,
    Harv
     
    Tony Martino and 19Eddy30 like this.
  24. 19Eddy30
    Joined: Mar 27, 2011
    Posts: 2,314

    19Eddy30
    Member
    from VA

    Harv, that the main Key to starting a engine with a Mag , Separate Kill switch off , let engine get to a good cranking speed ,Then turn Mag on . Most will try to start with mag on ,
    & then say ""Mags R Junk" witch is User error!!
     
    Tony Martino and Elcohaulic like this.
  25. blvdbill
    Joined: Feb 2, 2010
    Posts: 456

    blvdbill
    Member
    from California

    da34guy very cool sedan
     
  26. Besty34
    Joined: Sep 9, 2010
    Posts: 409

    Besty34
    Member

    Sorry Mike just saw this, I just used a piece of thick wall tubing I had lying around , just measured the coil and made it the same, you can leave the coil in and just drill right through it


    Sent from my iPhone using H.A.M.B.
     

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