Magnetos, and CDI

Black Magik

Black Magik

Member
I have been reading through the ignition system posts, and sub-links. I haven't seen too much on Mags vs CDI. I see an advantage to the CDI boxes that allow for programming timing curves. Of course Mags have their longer spark duration, and self generating power.

According to what I've read, the "multi-spark" (which I understand to be a gimic to extend spark duration to the levels of the Mag and HEI) of the CDI box reverts to a single spark after 3k rpm.

I keep seeing apples, oranges, and conjecture when they are advertising ignition systems. All I can see is that the engine really only cares about would be spark at the plug (duration of spark, and recharge time between sparks). Is there any place to locate the actual specifications on the different ignitions?

Magnetos are really mysterious and cool. I can't really understand why they don't have much info on them. After all they've been utilized for 90+ years... I have a feeling that it's more of the same experience I got from Edelbrock when I called about runner lengths, "that's proprietary information, we don't give that out".
 
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Magnetos do have a much longer spark duration.
Also more amperage current at the spark plugs.
Translates to higher Joules energy output.
 
As I understand it, faster you spin the more the output. When would they reach a decent operational spark production level, and when would they be operating at a peak or full spark output? From the descriptions, I am guessing it would be gaining power on a curve that may or may not plateau.
 
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There are different techniques to set up Magnetos for street use and also for full out Race Use.
The exact info is a closely guarded secrets.
They are precisuon timed by the custom builder.
I was taught by an Old Timer like Grumpy.
Where I learned my Vertex Magneto knowledge and rebuild blueprint skills with them.
I am a littlte guy Privateer like Grumpy.
I love building Vertex Mags.
I have a chance to build A Mag every 2-5 years for someone .
I have just rebuilt my own for Chevy, Pontiac & Oldsmobile V8 engines last few years.

Vertex Mags typically come on Very Hot by 2,000 crankshaft RPMS.
And don't lay down even at 9,000-11,000 rpms.
Actual Magneto rotor speed is 1/2 of crank Rpms.
 
That sounds perfect! The intake, that I'm working out the engine build for, would have the mag already coming on strong before it hit it's min rpm range. I dont believe that i would hit the high side of the mag though. I will need to post for help to get that expertise once I get the engine worked out.

I love math, and this site has me overwhelmed with knowledge. I want the insider, closely held secrets. My dad was one of those knowledgeable people... I just never got the chance to learn half of what he knew. The current state of things on most forums is either closely guarded secrets, or people who don't really know what was built for them. Knowledge is HP. :)
 
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they have plenty of amps to start any automotive V8 engine even at the low starter spinning over the engine rpm level ,
and as rpms increase the volts/amps increase,
and as someones bound to point out, even spinning the magnetos cam gear with your fingers and letting the ignition wires hang anywhere near your bare skin,
will quickly introduce you to the magnetos ability to reduce that bit of curiosity,
into the question of if a magneto in your hand can still generate impressive volts/amps
yes, the vertex mags work very well, no question there,decades of use in serious racing applications prove that,
but the new crank triggered individual coil per cylinder ignitions are very effective.
and should not be ignored.
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Anyone that has ever been HIT by A Vertex Mag spinning on a Running Engine or a Sun Distributor machine will never ever forget.
Like being hit with a Sledghammer.
A Cop Stun Gun or Taser is A Toy compared to A Vertex Mag I Blueprinted Rebuilt.
 
Not many distributor machines around anymore. But I use to load a condenser an toss it to someone to catch. LOL
 
T-Test said:
Not many distributor machines around anymore. But I use to load a condenser an toss it to someone to catch. LOL
Click to expand...
Lol.
I used to shock my little brother with charged electolytic capacitors .
200-500 Microfarads with a 300 -600 DC Power supply to charge them.
He would Jump....

Also used to have a few WW2 Aircraft - Tank Transmitter Radio Reciever Dynomotors.
600-900 VDC Output @500 Ma -750Ma current output.
They were insane Rotory Transformers to play with as a Kid.
I was into Ham Radios Shortwave Radios growing up.
 
Getting better at Making You Tube Vids.
Still takes me time to upload them.
Try and make a You Tube Vid of My Sun Distributor Machine spinning one of my Vertex Mags.
My 425-455 Olds OAC Vertex Mag still on it.
They Sound insane spinning.
DR FRANKENSTEIN. !
 
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