First, Are you sure it's the right coil?
Is it by any chance a 24 volt wagon but a 12 volt coil?
Or a 9 volt coil or worse, a 6 volt one? Sometimes it isn't easy to tell, and it may be that you are being supplied with coils that don't suit YOUR car.
The IGN coil will run warm, but should not run HOT.
If it runs HOT this can only be due to a very few things, most likely that the voltage of the car is more than the volts the coil was designed to handle.
I assume you are still using ignition POINTS and not some form of electronic ignition? Are you running a rev-counter?
Remember, many coils are designed to run with a ballast resistor in line. These coils are usually rated to see 6 to 9 volts, and the resistor drops the car voltage to that level EXCEPT when the starter is turning, so it gets a bit of extra high voltage spark on start up. These coils may not be marked with a voltage rating. Without that resistor the coil WILL receive about 14 volts instead of perhaps 8, damn-near double, and so it will draw nearly twice the CURRENT, and on the basic laws of leccy and physics nearly twice the heat will be generated, and that is too much. Eventually the coil will fry up and fail, and the extremely high secondary voltage will probably induce tracking and leads and caps and rotor breakdown all the sooner.
Don't trust any coil except one clearly marked 12 volts.
But, if the engine runs there can't be much wrong with the wiring, though a new condenser from time to time is a good plan.
CharlesY
