Last fall I installed a Petronix II Ignitor in my 66 (6-300), along with the Flamethrower coil that was recommended to go with it. I've noticed that when it's run for a while, the coil seems to get really hot. Is this normal? The system still has the pink resistor wire on the ignition system. Should I leave it?

 

They do get pretty toasty, because they pass a lot of current. How hot is "too hot"?

The ballast or dropping resistor cuts back on some of that heat and it won't run any cooler if bypassed. Make sure the correct coil for your application is installed. Sometimes people will install a low resistance coil and run into trouble.

 

Thanks Tedster. I'm not sure how hot is too hot. I happened to touch it after a drive and it seemed pretty hot. It;'s been running OK. Based on that and what you've told me, I guess it's fine and I'll leave well enough alone.

 

Well if you pencil it out in terms of Watts - I'm not sure exactly how that works, because a coil doesn't exactly run at a 100% duty cycle.

But it must be something like 2 to 3 amperes on a constant basis. So as a very rough estimate an ignition coil would dissipate or get about as hot as a 25 watt incandescent light bulb, say. Maybe you're too young to remember those lol.

Maybe you know this already, but this is why the ACC key position is always used for the radio and such when engine is not running. If the key switch were in the RUN position (without actually running) the ignition coil will usually be ruined in maybe a half hour, due to the excess current flow. If the points happen to be closed, they may be burned. Early Pertronix modules will be roasted.

Pencil out your setup, Pertronix I modules don't want to see more than 8 amps iirc.

 

Don't know if it would cause any noticeable problems, but If you have a Flamethrower II coil, it doesn't need the resistor wire. It should have the full 12 volts.