1970 Cuda electronic ignition question re ballast resistor

[usraptor]

When I restored by 1970 Cuda with it's 440/512 stroker with 10:5 compression I changed to an electronic ignition. In the process I also added a new stock Ballast resistor.  The engine runs great with this set up but occasionally is difficult to start when cold, especially if the temp is below 50 degrees.  It will spin over and over and wouldn't fire.  I assumed that the problem was that I had the choke adjusted to tight and had flooded the engine because if I would leave the ignition on for a few minutes and allowed the electronic choke to heat up and them open the butterfly it would usually start right up. When warm it fires fine.  (I haven't readjusted the choke yet since I have a shaker hood and it's a pain to take off to get to the choke and the problem only occurred occasionally during the summer months.  It's on my winter to do list for the car)

I was just reading the current issue of Mopar Muscle magazine and noticed something in the article about rewiring their '65 Coronet engine compartment to handle a 528 CI St Hemi.  As shown in the attachment they re-wired the ballast resistor by removing the ballast and replacing it with a 10 gauge wire so that the MSD electronic ignition would have more voltage to perform properly as they claim electronic ignitions need direct alternator voltage to go to the coil.  I've never heard of doing this before.  I don't have a MSD electronic ignition, just the regular Mopar style ignition with the blue box.  However, after reading this I was wondering if my hard start when cold might be due to low voltage going to the coil since my ballast resistor is stock.  I thought it was because I had flooded the engine but the engine also sounded like it was not getting any spark or at least hot enough spark to fire since the engine doesn't even cough when this happens.  Any thoughts on this?  Should I try replacing the ballast with a 10 gauge wire?  Will this hurt anything if I do?

[JS29]

 

[HP_Cuda]

The reason for the ballast back in the day was to save the coil. It will run for short periods at 12V to start the motor but then drop down to 8-9V during run time.

Guess the question is: do you run a stock coil?

[dodj]

Depends on the electronic ignition you installed. Installing a 10 ga wire in place of the resistor is stupid in my opinion. 14ga would accomplish the same ends. But this is because the MSD ignistion has no need of a ballast resistor. If you have an MSD, the same would apply. Eliminate the resistor.
If you have a stock style ignition with a 4 pin electronic box, you require a single resistor. Do not replace it with a piece of wire.
If you have a stock style 5 pin, you require a dual resistor. (but you probably don't have a five pin ecu.)

[RUNCHARGER]

I've heard of people doing 12V direct with Chrysler electronic. I'm not smarter than the Chrysler engineers so I use the stock Ballast setup. It would not help with starting BTW as the voltage is reduced in Run, not in Start.

[Katfish]

I've heard of people doing 12V direct with Chrysler electronic. I'm not smarter than the Chrysler engineers so I use the stock Ballast setup. It would not help with starting BTW as the voltage is reduced in Run, not in Start.

Good point and exactly true.  Full voltage applied during start.

[usraptor]

 Thanks everybody.    It's obvious that when it comes to electronics I'm not the sharpest knife in the drawer.     Thanks for clarifying that the full voltage is applied during start up.  I guess I'll get around to resetting my electric choke.

[Chryco Psycho]

A higher output coil and or better / lower resistance  ign wires & opening the spark plug gap up to .040 may all help starting

[Bullitt-]

You might want to check the voltage coming to the coil while cranking... Should be the full battery 12+ volts, if not there is an issue with wiring/connectors or the battery that the cold temperature is making worse.

[usraptor]

Thanks Chryco and Bullitt.  I'll check those out.