Hey all! I'm having serious problems with my ignition system to the point that my ignition coils are super-heating and burning up. Here's my current setup. 1966 Skylark with a 300 motor. I'm running a rebuilt stock distributor with a Pertronix Ignitor. For a coil, I'm using an Accel SuperStock coil with 1.4 ohms of resistance. Recently, I ordered a new engine harness from M&H, and I had them do the HEI conversion since I'm runing Pertronix. This removes the resistance wire so I'm getting full voltage at the coil. Voltage-drop from the alternator to the coil is less than .5v, so when the alternator is outputting 14.2v, i'm seeing ~13.7v at the coil. The coil was getting SUPER hot. I mean heat of the sun hot. The car would drive for a while then stall out because the coil would overheat. At first, I thought it might be because it was mounted on the intake. I moved it to the firewall where it would be cooler. That turned out to work for a while but was really a band-aid as now it went a little farther before dying out. Recently, I installed a 1.25ohm ballast resistor, bringing the voltage to the coil down to about 11v. Now I'm under 12v at the coil, but man the thing still seems like it's getting really hot. I compared to my '65 442 coil, running a Pertronix Ignitor II, and that coil stays relatively cool with the coil on the intake manifold. I'm at a loss here, guys. Is there something I'm missing?
Though it is just a guess, I suspect that the combination of the Pertronix ignitor and the HEI conversion, including the coil is allowing excessive coil current. I suggrest the use of the 1.4 ohm resistor in line with the voltage supply, and see if this alleviates the problem. If the Pertronix ignition is multiple firing the coil, the extra current will overheat the coil. Also, if the ignition is doing the usual thing with a factory coil, which is to increase the coil current, the resistor will help. Ray
Alot of the Acell coils are made in Mexico, and Taiwan. They have layer shorting problems. Try an American Made coil like the NAPA IC12, or the MSD 8200. My MSD Digital 6 box fried an Acell coil in a couple of hours. American made coils have a segmented crimp at the top of the coil. foreign made coils are crimped all around.
