Ive always been curious abpout running a mad ina street car and was wondering ow many Hambers who run Flatheads actually run a mag? Im curious as to what kinda difference the mag has made compared to dual point or electronic ignitons that may have been previously used? I hear they talk HP to run/drive? What are the pros and cons of running a mag in a flathead? Any info would be great? Rat
I just sold my Joe Hunt mag to a HAMBER in Southern Oregon. Reason I sold it was that I wanted a soft rev limiter and boost retard for my blower...............other than that I would be running it. I had in a 56 Chevy 40+ years ago, and it ran great. As for taking HP to run it, well the higher the RPM the hotter the spark, and marginally more resistance to run it than a regular distributor. Worry free and single wire plus I like the idea of the kill switch being located only where you know it is, kind of like an alarm system. They are a lot more expensive because of the "rare earth" magnets, but you can also buy a mag look-a-like from Joe Hunt or Vertex. I just love the look!
Thanx for the input man...that blown flatty lookin a peach. You must be close to fire up? Im not running a mag for the same reason - the blown flathead runs real good with the MSD 6BTM with boost retard/rev limiter. But I am interested in the mag for perhaps another build. Anyone else using a mag? Rat
We use a vertex on our flathead in our salt truck and also have driven it on the street to car shows etc. The hp drag is a myth as they really use very little HP to run. I run them on a test bench that has a 1/2 hp motor at 8000-9000 rpm with little drag on the electric motor.
Yeah man, always wondered how they work and what makes em good. Maybe it was the cold in your shed the other nite haha !! BTT Rat
I run a 1939 series 1 Scintilla Vertex on the green 32, dual Wico's on the "El Gato Grande" lakes special and I ran a Vertex on my blown gas drop tank at bonneville, all work very well. Rember if your battery go's flat just get your buddies to give you a push start (asuming it's a real hot rod with a manual trans).
I run an older vertex on my roadster, it starts perfect and revs up with no problem, as far as performance gains I couldn't feel anything that I noticed, I keep a rubber cap for it so when it's raining I throw that on, there not to hip to being wet. I may try a Ducoil soon but only because I have some neat old coils I want to try. Pros.......starts great, runs fine, looks killer, will run if charging system dies. Cons when the mag quits it quits, when the coils go inside your stuck.....unless you rig up an external coil to get you back going by just using the points in the mag, good luck with her.
I haven't used a mag in a street car, but I've used them in race cars. The main reason these were so widely used in race cars is simply because they don't require an electrical system. Assuming all things being equal (proper setup, curve) there shouldn't be any performance advantage over modern electronic systems. I don't see any advantage unless appearance is a factor. The way you kill a mag is to ground it out. So, the kill switch is actually in the "on" position to kill it. In other words, you turn the kill switch on to ground it out, turn it "off" to break the ground and it's ready to fire. Some folks have been hurt by not understanding this and inadvertently firing one. So, on a street car, using a conventional ignition switch is a bit of a problem. On, dead, off hot. So, a separate kill switch is needed. I've heard of a hot/break relay system being used, but I would still want a hard wired kill switch for safety. Also, way too easy for theft. I would want a very secure fuel system cut-off.
I've heard with a mag, your plug gap needs to be around .022, as opposed to .030 with a conventional distributor. Anybody know if this is true and why?
It certainly is true. You need to reduce the plug gap when using a mag. The gap should be between .012" and .022". Anything bigger puts an unnecessary amount of stress on the coils which will eventually burn them out and dramatically reduce the life of the magneto. I believe excessive plugs gaps when using a mag is the single reason why mags have got a bad name when it comes to reliability and poor starting.
I was just talking with a current Bonneville record holder (forget his class, but it's a blown flatty powered '34 coupe), and he says they switched from a mag to a Chevy HEI and picked up a couple MPH. But, I think they probably lost in the "looks" department.
I've run a Vertex in a 3/8 X 3/8 with Evans heads and 3 97's fed by a 400jr. No problems at all. very drivable, starts fine etc. Just don't EVER turn the motor over by hand with out the mag grounded or you are likely to lose a hand! Same goes for turning over the crank with a wrench to check timing or valve clearances.
Hey, You start a discussion on Mags without me?!!!!!! I want one as well, pitty they dont come in a front mount flavour for the early motor... Dan
they do dan, pretty rare i think. usually a short angle drive, or ive seen them with two four cyl mags in a vee shape, now THAT took some thinkin out...
pretty sure i understood your message. there are mags for early motors, 32-48 front mount distrib. Pounden, Harmon & Collins, V style Wico's etc... i picked up a home made twin mag setup using a 37 distributor housing, it wont clear block mounted water pumps but it may clear head mounted pumps.
Here is what you want. I run on on my car with no problems. Except for the modifications to make it fit.
I have run a mag on flathead street engine for years. (H&C) They start just the same as a battery ignition. Quick. The ones with the original coils ran best with around a .015 to .020 plug gap...The ones with the new aircraft coil conversion can run quite a bit more gap..I run .040. A bit of advice, do NOT take a mag off an engine without grounding the kill terminal and that means NO clip leads..Use a screwed on wire. If the mag turns and you get bit, YOU WILL DROP IT...Could be costly fix.
I've run one on my flathead for about 30,000 miles without much problems however I did have to replace the coil but I think that was from too much plug gap, now I gap plugs at 017 it starts good and looks a lot better than a piss ant stock looking dizzy "Doc"
I've ran a Harman-Collins on the street and at the drags -- ran about a .020 plug gap (original coil). The primary reason I ran it was for the hot spark and the simplicity . . . just one ground wire to shut it down. I previously ran a HC dual coil -- was much more of a PITA to keep running . . . just more crap to go wrong. One thing to think about is the advance mechanism . . .or lack thereof. The H&C mags are locked down - no advance, so what you set is what you get. This does make them a bit harder to start . . . but not if you're running a 6 Volt starter on 12 volts . . . spins em' right up. The Vertex mags have mechanical advance - so you can at least setup both an initial advance and an appropriate curve. On a blown motor it is not that much of an issue in that I only ran about 15 degrees total advance anyway -- but on a carbed street motor, I would probably like to have setup the flathead at 10 - 12 degrees initial and another 10 - 14 mechanical . . . coming in pretty early (probably all in by 2000 or 2500). If you're boing to buy a new mag, then the best setup would probably be a Vertex type setup . . . running the late 49-53 timing cover and cam gears. Quite a few guys can supply flathead drives . . . Joe Hunt, Don Zig, etc.. Just make sure you have the mag setup for a flathead advance curve - as flatheads don't need much advance (so don't just rework a SBC mag and throw it on!).
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