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Quote:
Originally Posted by arc40s
Question: 
I have a 8BA engine with 12V can coil.
Stock single point dist.
After about 56-60 miles the coil get so hot it start mis fire losses power and then just stops and wont start or run. change to new coil starts right up for another 60 miles and stops again.
coil has internal resistor.
tried one coil with out resistor same results.
What causes coil to become so hot it stops working and how do I keep things cool?
vehicle is 1940 Ford Pickup aluminum radiator. Temp of engine fine, normal range.  |
Actually the issue of heat is wattage. Wattage comes from resistance. Low resistance causes heat build up.Ex: Using a 1.5 ohm resistor AND a 1.5 ohm resistance primary coil the total resistance would be 3.0 ohms. 3.0 ohms divided into 14.6 volts of a running , charging engine would be 4.8 amps ( or less with some heat build up, causing resistance to increase). Amps xs the voltage= watts (or 70 watts in this example) This is approx normal amps for a ignition primary.
Now lets use the coil on my desk Pertronixs Flamethrower of .6 ohms resistance. 14.6 volts divided by .6 ohms would be 24.3 amps !!!!!!
OR 354.78 watts!!!!!!! Thats 5 times the amount of watts!
Happens every day..........cant do it !!!!!