I just bought a 30 coupe with a 39 flatty and a "helmet" dist.. builder said it had a petronics unit in it.. well long story short, while driving it cuts out and runs bad.. with key on I get 4 1/2 volts at the coil. It has a 1.5 ohm resistor, so I cut the resistor down so I get 6 volts at the coil... now it runs great!!! Now my question is, is this going to be reliable?? I'm new to flatheads and 6v stuff.. thanks guys!! Nick Sent from my iPhone using The H.A.M.B. mobile app
Generally you don't need a resistor on a 6 volt system, but it may pay to check your coil's primary resistance to make sure you don't damage the ignition module. I'm sure the manufacturer can tell you the minimum coil resistance that's acceptable.
Well it's definitely a 12v system in the car..but the dist. and coil look stock.. I'm guessing it's a 6v ign system... Sent from my iPhone using The H.A.M.B. mobile app
FWIW I have a Petronix ignition system in my '39's helmet dist. and it works fine. My system is also 12v. but the ignition system is 6v. I have been told (by the Petronix people) that ALL ignition systems are actually 6v. from the coil onward. They also said that the 12v. coils have a built-in resistor to cut the voltage to 6v. when it goes to the distributor. So 6v from the coil regardless how it is done is what the ignition system needs.
39wagon do you run a resistor before the coil? Or are you just running 12v to it?? Sent from my iPhone using The H.A.M.B. mobile app
I'm just running 12v to it; my coil is for a 12v system and has an internal resistor. The only external resistor I have in the system is to the dash; the gages/dash lights are all 6v. I've got 12v head/tail light bulbs cause the 6v ones (like me) aren't all that bright....
Oh ok.. I have no idea what coil is in there.. probably just a stocker. I wonder how much stock coils could can handle Sent from my iPhone using The H.A.M.B. mobile app
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