Mag or electronic ignition.

[George]

It's time for a new thread.

 I currently run the MSD 12LT magneto with a tach convertor to run the rpm modules. We upgraded the engine last year and the engine builder/ dyno operator talked me into a MSD digital 6 + system. We dynoed the engine with a MSD 6 with good numbers. MSD told me not to run the Digital 6 + if I were using the same battery for both the ignition and to start the car. I didn't see any on track difference between the Digial  6+ and the 12LT mag.

Spark plug gap is the reason I tried the electronic system as I could run a .030 gap. With the mag .018 is the maximum. I'm told the wider you can open the plug gap the greater the potential power.

What's your take on this? Thanks. George

[slingshot383]

With my injected alcohol motor and 14.5:1 compression, I was told to take off the MSD 7AL3 and go to a mag.  Now I'm putting a blower on , and the mag is the only way to go.

[wideopen231]

They make ignition other than a MAG?

[George]

They make ignition other than a MAG?

Yes, and there are some very fast cars running them.

[wideopen231]

yea those old long cars running two mags are so slow at 330 mph in 3.7 seconds.

 If god wanted man to run other ignitions he would have gave man brains to make magneto's. I'll take a MSD mag any day.Besides not all cars have a battery on board.

[George]

From what I am learning battery development is gaining on this question. I need ballast on the front of my car, why not make it useful? If I can hang a powerful battery on the nose of the car and not have the added $$ of initial cost of a  magneto and the $$ of having it tested on a regular basis. A magneto is a generator , several moving parts= service $$. Just got mine back today. A $300 checkup .


In my next project I will take a hard look at a 16 volt system.

[George]

Old long cars? Surely you are referring to the modern 300' cars running twin 44 amp systems?

[wideopen231]

Yea that would be the ones.Maybe ol' instead of old is how I should have stated it.

[wideopen231]

First I do not see where it would not work fine in that combo.  Seriously i think either style would work fine I just like magneto myself. I also happen to have 2 mag 12s that ran great on blown alky motor making 44 lbs boost. Bob Newberry once talked with me and Barry Patton about the larger mags and said he could not find any advantage to the bigger ones on alky. I guess someone did since most all top alcohol(blower) cars are running mag 44 now days and of coarse the A/Fuel cars are running two of them.
   Only draw back to mag IMO is most the time they are happier firing a motor that is spinning pretty good,they can be unhappy with slow spinning motor.

[George]

What plug gap did you run with the blown alky combo?

Is a slow spinning engine an engine being started ? If so would a system higher than 12 volts be better?

[wideopen231]

I'm going with 16 volt battery for this reason. I have been told by lots of folks it will spin considerably faster. Now if you had to add weight 2 battery would spin the crap out of it but thats about 75 lbs total so probably not good thing.

   We ran NGK 9 plugs in funny. Im pretty sure but its been good while.

[George]

Do you remember the Gap?

[wideopen231]

Im sure there's cpl out in shop I'll look around tomorrow.

[slingshot383]

The MSD looses it's edge above 3000rpm, and the Mag really shines above 4000 rpm and at high cylinder pressures.  It's a combination of amps, and duration of spark that makes an ignition system, and without an alternator, the MSD doesn't have the same juice at the end of the day.

[George]

The MSD looses it's edge above 3000rpm, and the Mag really shines above 4000 rpm and at high cylinder pressures.  It's a combination of amps, and duration of spark that makes an ignition system, and without an alternator, the MSD doesn't have the same juice at the end of the day.

It's boiled down to these two questions.

How does the MSD perform with a 16 volt battery compared to a 12 or 20 amp mag. In a blown alky engine combo.

 If the ignition system will support it, will increased spark plug gap make more power.