Hot Rods Hot coil, revisited

A while back I had noticed my MSD blaster coil getting hot to the touch while the car sat with the key on. Realized its probably just how things go inside my Mallor Unilite flat top distributor and I dont leave the key on when car isnt running.

Recently my T bucket has been running a little sloppy and hard to start. Checked the plugs and cleaned the carb and it helped some.
I also noticed that the cap on the coil is cracked so I started paying more attention to the coil again. Once running the car the coil is hot enough to fry an egg on. I realize it'll get hot when running but its HOT!! Coil is sunk into the firewall, so it gets little to no airflow around it. For this I'm going to wire in a computer cooling fan to circulate the air under the firewall/dash better onto the coil.

Its an electronic, non point distributor, wondering if maybe I should also consider a resistor on it? Currently running the blaster, hot 12v wire to the coil when the key comes on, and 12v until it shuts off and the Unilite distributor.

Anyone have better ideas for me to prolong the life of a coil in this thing? Im at about 6 months on this one now

 

You probably should install a ballast resistor with that combination. MSD coils are proprietary designs, designed to work with their ignitions. If your Mallory ignition doesn't have either dwell control or current-limiting circuitry, that would explain the high temps. MSD uses current-limiting, adding current as RPM goes up. It's slow-speed operation that causes coils to overheat.

 

Just did some searching based off seeing Mallory coil. Turns out they make one the recommend for the distributor, and they recommend a resistor even though its electronic ignition. So ill be swapping to those.

 

Check the primary coil resistance on both and compare. If they're the same either one will work as long as you use a resistor.