Register now to get rid of these ads!

School me on magnetos

Discussion in 'The Hokey Ass Message Board' started by ratty_aussie, Jul 30, 2013.

  1. Hey guys as the topics suggests, what are pros and cons of running a mag on a ford flathead v8? I'm very new to that sort of thing.

    Posted using the Full Custom H.A.M.B. App!
  2. blowby
    Joined: Dec 27, 2012
    Posts: 6,492

    from Nicasio Ca

    This should be interesting. I have never run a magneto or a car but lots of them on motorcycles. As you probably know magnetos create their own electricity (spinning magnet and coil, or vice versa), and the faster they spin the hotter the spark. Spark at starting speeds can be weak, that is why airplane magnetos have impulse couplings that actually snap the magneto around to help with the "spin". Maybe car magnetos have it too?
  3. racer756
    Joined: May 24, 2006
    Posts: 1,324


    I run a magneto on a street driven Corvair. Never had an issue. Car runs like a champ and the cool factor is worth it. I will also run a mag on my 324 Olds powered, coupe that is under construction .
  4. Pete1
    Joined: Aug 23, 2004
    Posts: 1,726

    from Wa.

    I will assume you are talking about street use.
    I have run H&C mags on several street engines. They work fine. They start easily.
    If you have an engine with a lot of compression, it will sometimes try to kick back when starting and bend the starter shaft or break the bendix spring if you are using a stock starter. A gear drive starter remedies this.
    The problem with the H&C mag is, no mechanical advance. Set it about 23 for the street and forget it. This a slight compromise for top performance or gas mileage.
    A way around this is to modify an Offy lead plate to take a twist lock type choke cable.
    You can play with the advance as you drive then.
    I have never run a Vertex type mag but some of them have mechanical advance in them and that would be good for the street. They start easily also.
    Register now to get rid of these ads!

  5. racer5c
    Joined: Nov 30, 2002
    Posts: 2,218


    running a vertex in my model A flathead roadster have driven it all over the country no problems, had it rebuilt by magtech in Indianapolis also had them install a mechanical advance, worth every penny I spent with them
  6. TERPU
    Joined: Jan 2, 2004
    Posts: 2,217


    Set it and forget it, I have one in everything I can drive. They are worth what they cost for sure.
  7. Pete1
    Joined: Aug 23, 2004
    Posts: 1,726

    from Wa.

    Racer5C, Neat avatar. My kind of racing.
  8. Learnt some new stuff.

    Posted using the Full Custom H.A.M.B. App!
  9. Wild Turkey
    Joined: Oct 17, 2005
    Posts: 903

    Wild Turkey

    How are they on spark plugs? We ran some Vertex mags on 413 Chrysler irrigation engines back in the 60's and plug life was a small problem.
  10. mashed
    Joined: Oct 15, 2011
    Posts: 1,474

    from 4077th

    Yep. Ran one on my bike for many years. Took it to an old Quonset hut at the Oakland airport to have the magnets recharged. Worked great but get a spot of water or oil in it and it'll refuse to fire.

    Had an old Wisconsin horizontal shaft engine I got from an old roofer's winch that had a Hunt impulse-coupler magneto on it. Stretched an old Bonanza minibike frame to fit it and it gave the Briggs Raptors a run for the money.
  11. So-Cal Speed Sacramento
    Joined: Sep 6, 2008
    Posts: 463

    So-Cal Speed Sacramento
    Alliance Vendor
    from Sacramento

    They're great! We've got a couple cars running Harmon Collins and they work very well and are very 'streetable'. If you are running a 1942-1948 two belt system you may have to run idlers on the fan belts though. The mags are quite a bit larger than the stock distributor and some have tendencies to hit the fan belt.
  12. TERPU
    Joined: Jan 2, 2004
    Posts: 2,217


    I've had the same ones in my Chevy for almost 7 years now and have beat it pretty good. The trick is in the wires. You gotta run the right wires. My 331 Cadillac has a Mag in it as well and has regular HEI wires on it. They are for a hotter spark and work just fine. The reason you had to change wires in the old days was due to the low resistance style old wires. A Mag would cook them quickly. On the flip side if you are running an old ignition points and condensor stuff you will be amazed at how much better your car will run with a set of honest to goodness low resistance wires. Plug wires are a very often overlooked aspect of the ignition system

    All the best,

  13. Cool thread. wanna run a Vertex on my '59 Holden 6.
  14. fenderless
    Joined: Mar 31, 2006
    Posts: 1,285

    from Norway


    I'm just to modify a Vertex/hunt magneto for my Flathead.
    As we are doing dragracing, we don't need the built in advance.
    My Vertex that I bought from a friend, was refurbished by Hunt.
    It had 24 degrees built in (on crank). That should be a good set-up for street use. In order to use this on the street, one needs to set the static advance to "0" on the crank. the engine will start easy, then on higher rpm's, approx. 2000 rpm, you will get the 24 degrees.
    This is about the same as Pete1 said:)

    If you have an 8BA and don't have the magneto, you can buy an used magneto for sbc or bbc, and easily modify it to fit the 8BA.

    the picture show the difference between a 24 degree magneto vs. 0 degree magneto.



    Attached Files:

  15. Rusty O'Toole
    Joined: Sep 17, 2006
    Posts: 9,106

    Rusty O'Toole

    In the early days of cars (like before WW1) magnetos were the best ignition, found on expensive cars. Then Delco came out with the coil ignition we are all familiar with and magnetos disappeared. Except on race cars and aircraft where their simplicity (no electrical system required) and hot spark at high speeds made them desirable.

    Today's electronic ignitions will equal or beat the best magneto. You can run one for the nostalgia kick but there is no longer a performance advantage, and a mag can have disadvantages in starting, cost, etc. as already described.
  16. nxcess
    Joined: Mar 30, 2013
    Posts: 109

    from Mesa, AZ

    If you are running it on the street you will have to either run a separate kill switch. A mag does not use 12 volt input. It needs a ground to shut off the engine.
    I did one for a customer that wanted a key system with start and run. I hooked up the run side to a relay that when the power was turned off it grounded the mag.
  17. Old Tin and New Tin
    Joined: Jun 2, 2011
    Posts: 301

    Old Tin and New Tin

    Been running a Vertex mag made in 1978 on my 5 window since the two Taylor-Vertex look-a-like mags crapped out and Taylor-Vertex won't do anything about them. Starts immediately and runs fine. Wired it through a relay in order to power and ground the mag through the ignition key. Using Taylor Spiro-pro wires and spark plugs gapped at .020. Only draw back is "noise" emitted by the magneto as the rpm is increased which affects the electronic tach and speedometer. Working on using shielded wire which is grounded similar to that used on aircraft to see if this cures or lessens the problem.

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.