Question On Wiring of Pertronix 1281 with Flame Thrower Coil on 57

[TJShea]

I have had the 57 about 4 months. After reading threads about the Pertronix 1281, and decided to buy one and mate it up with a Flame Thrower coil. Learned one lesson-Received new stuff, removed distributor cap...There is a Pertronix 1281!! However, it is hooked up to a stock coil, which is hooked up to the resister right next to it. The threads, and parts suppliers, led me to believe that the "hotter" coil was needed. However, maybe that's not really so, as the car is running. Anyway, the instructions for the 1281 and Flame Thrower contradict each other. The 1281's-keep the resister. The coil's-by pass it. The coil is 1.5 ohm, and I think that is what the resister is too.
So, can I just leave the wiring set up as is, and attach the Flame Thrower coil exactly as the current one? The reason I thought this might be necessary is there are two wires leading from the top connector on the resister (I assume power out). One goes to the carburetor, the other looks like it goes to an electric fan that has been installed on the front of the radiator. I felt if I by-pass the resistor, that would negatively impact the those hook-ups as it think it would cut off power to those two wires. I called tech support at Pertronix, they are closed until Monday. Thought I would try here. I guess I could leave well enough alone. Just thought there could be a benefit to the hotter coil. If I can hook it up just as the stock, that would be perfect. As you might tell, I am below amateur when it come to electrical issues.

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[CtCarGuy]

I have had the 57 about 4 months. After reading threads about the Pertronix 1281, and decided to buy one and mate it up with a Flame Thrower coil. Learned one lesson-Received new stuff, removed distributor cap...There is a Pertronix 1281!! However, it is hooked up to a stock coil, which is hooked up to the resister right next to it. The threads, and parts suppliers, led me to believe that the "hotter" coil was needed. However, maybe that's not really so, as the car is running. Anyway, the instructions for the 1281 and Flame Thrower contradict each other. The 1281's-keep the resister. The coil's-by pass it. The coil is 1.5 ohm, and I think that is what the resister is too.
So, can I just leave the wiring set up as is, and attach the Flame Thrower coil exactly as the current one? The reason I thought this might be necessary is there are two wires leading from the top connector on the resister (I assume power out). One goes to the carburetor, the other looks like it goes to an electric fan that has been installed on the front of the radiator. I felt if I by-pass the resistor, that would negatively impact the those hook-ups as it think it would cut off power to those two wires. I called tech support at Pertronix, they are closed until Monday. Thought I would try here. I guess I could leave well enough alone. Just thought there could be a benefit to the hotter coil. If I can hook it up just as the stock, that would be perfect. As you might tell, I am below amateur when it come to electrical issues.

The purpose of the resistor was to lessen the wear on points after the car started. This is not used with Pertronix. They are very clear on that. I put in a MSD in my '56 and bypassed the resistor. Works great. The wires are a big question. The coil wires have no relationship to the carb or fan. One wire is power from the ignition (and powers the Pertronix) and the other is the pulsating negative post. (Cyclying needed to charge the coil.) I think someone goofed up the wires. Pertronix will run with the external resistor but not to full output. The coil has internal resistance as needed. I hope this was helpful. How about a picture and color codes of the wires? It might help.

 

[2from93449]

I just had the PerTronix 1281 ignition and Flame Thrower coil installed. I know the resistor was one of the stock parts I bagged up. I talked to Pertronix a couple of times, they are very helpful, give them a call at 909-599-5955.

 

[TJShea]

Here are photos of the current coil and "resister". The top red wire looks like it goes to the front of the car in front of the radiator where there is an electric fan. I assume it ties to the fan, but i can't tell The blue wire attaches to what looks like a choke housing on the passenger side of the carburetor.

 

[CtCarGuy]

Here are photos of the current coil and "resister". The top red wire looks like it goes to the front of the car in front of the radiator where there is an electric fan. I assume it ties to the fan, but i can't tell The blue wire attaches to what looks like a choke housing on the passenger side of the carburetor.

The pale red wire on the coil is ignition power. This wiring has been worked on. If one wire goes to the choke (after market electric), the voltage to the coil can be less. This is a common mistake when adding a choke. The heavy red wire on the resistor is not orginal from what I can see. Go look at someone else's conversion. Calling Pertronix is a very good idea.

 

[Hadderz]

Yep, I'd say someone needed an ignition switched power feed and pinched it off the coil! Best to run a new wire to the fan and choke and leave the ignition its own.

 

[TJShea]

Thanks for the insights Hadderz, I believe you are right. I am just guessing because what I know about electricity is limited to flipping on a light switch. I believe that who ever did the wiring mods, wanted the power to only run when the ignition was on. So, the power for those chock and fan is coming off the positive side of the coil, through the resister. The car is running fine with the Ignitor model 1281, the stock coil and the resister. I could just leave well enough alone. OR, I could do what most guys like to do, and monkey with it. I believe I could install the Flame Thrower coil, with the 1.5 ohm resistance, which should match the current resister. Ditch the resister, and attach the two aftermarket wires that were added directly to the positive side of the coil. I hope....... I spoke with a tech at Pertronix, either way works for them. I just can't figure out if there is any advantage going away from the stock coil and resister, to the Flame Thrower coil and no resister.

 

[Hadderz]

Thanks for the insights Hadderz, I believe you are right. I am just guessing because what I know about electricity is limited to flipping on a light switch. I believe that who ever did the wiring mods, wanted the power to only run when the ignition was on. So, the power for those chock and fan is coming off the positive side of the coil, through the resister. The car is running fine with the Ignitor model 1281, the stock coil and the resister. I could just leave well enough alone. OR, I could do what most guys like to do, and monkey with it. I believe I could install the Flame Thrower coil, with the 1.5 ohm resistance, which should match the current resister. Ditch the resister, and attach the two aftermarket wires that were added directly to the positive side of the coil. I hope....... I spoke with a tech at Pertronix, either way works for them. I just can't figure out if there is any advantage going away from the stock coil and resister, to the Flame Thrower coil and no resister.

Understand especially if you're not electrically minded. So is the coil a benefit, well I'm sure the manufacturer claims so!! The resistor was added for better starting as when cranking the engine the voltage would drop so the original coil was manufactured to work on less than 12volts for that reason. Once running the voltage would increase so the resistor keeps the volts at the coil lower. I think that these new colis use no resistor and work on less than 12v to produce a decent spark but also on 12-14volts to give a better spark! As you say, if its running and running well then theres no point BUT if you've brought the parts.......

 

[TJShea]

Well, I took the plunge and tried out the new Pertronix coil, in place of the stock coil and resister. I found that the Pertronix Igniter that was already installed in the distributor was only hooked up to the coil, and was not attached to the resister. So, I changed the coil, removed the wire that went from the positive side of the coil to the lower electrical clip on the resister. The car started just fine, and ran for a sight moment and immediately died. Tried it several times. Each the same result. Strongly fired up immediately, then immediately died. I put the old coil back in, reattached all of the wires as before, and it started and ran. I think I will leave well enough alone, and when I have some work done later at a shop, i'll have someone who actually knows what he's doing take a stab at it.
Thanks for all of the info above.

 

[Pink T-Bird]

So, I changed the coil, removed the wire that went from the positive side of the coil to the lower electrical clip on the resister. The car started just fine, and ran for a sight moment and immediately died. Tried it several times. Each the same result. Strongly fired up immediately, then immediately died.

This sounds like a slight mis-wiring. The 12V from the starter solenoid got it started. As soon as you release the key it switches to power from the ignition switch, without it it will stall. Somehow your attempted coil setup without the resistor failed to get power to the coil from the ignition switch. There should be 2 factory wires to the + side of the coil, one from the starter solenoid and one from the ignition switch by way of the resistor. If you are missing one the car will turn over but won't start, if you are missing the other the car will start but stall as you release the key. You have 3 wires there, based on the second picture??? So one must be the electric choke? Looks like a prior owner or mechanic has done a bit of "customization" to your wiring, so that makes it "like a box of chocolates" as Forrest Gump would say. You may want to get someone with a multi-meter and some experience to figure out what's up.
The electric choke benefits from a 5- 8 V power source, It will almost certainly open too soon with 12V. However as others have noted it shouldn't come from the coil's ballast resistor. However, as you will be going to a setup without a ballast resistor for the coil you could repurpose that resistor to power the choke. Aesthetically you might be able to make it look stock? (Well except for the big decal on the flamethrower) If not, NAPA, CarQuest, Advance, etc. can get you a dedicated resistor for the choke. They are usually black and about the size of an ice cube with a mounting tang you can bolt to the firewall or the intake.
For your cooling fan - you want a full 12V, AND you don't want to rob power to the coil. That should get rewired, maybe with a relay to reduce the amp load through your ignition switch.
PS - make sure you re-attach that spring clip to keep the distributor cap in place (second picture).

 

[TJShea]

"Pink T-Bird" Thank you. This helps a great deal. I think this is what I maybe have going on. In the second photo you can see a pinkish colored wire going to the + side of the coil. More than likely this is coming from the solenoid and that is why the car would start as I had attached that wire to the + side of the Flamethrower coil. The three wires attached at the top of the resistor include the power wire from the ignition. I believe that must be the lower wire of the spliced wires "Y" formed in the black covering. That wire is also supplying power to the choke, through the blue wire in the upper part of the "Y", and the red power wire going to the electric radiator fan. Plus it is sending power into the resistor. The black wire from the bottom of the resistor goes to the + side of the coil. This is taking the power from the the ignition, coming in from that lower wire (Ignition wire) in the "Y" at the top of the resistor, reducing the voltage, and then it goes to the + stud on the coil. That was not connected to the FlameThrower coil, which is why the car immediately stalled. Therefore, power coming from the ignition goes to the fan and choke before the power goes into the resistor.

I should be able to take the lower "Y" wire from the ignition and attach it to the + stud on flamethrower coil, along with the wire from the solenoid. That should have both wires to the+ side of the coil, the one from the solenoid and the one from the ignition. I can continue to take power from the ignition to power the choke and fan, as it is now., and no longer use the resistor. At least, that is what with my very limited understanding of electronics, I think should work. OR , I could just leave well enough alone and not chance screwing everything up. Just hate to have a perfectly good new part (Flame thrower coil) just sitting in a box begging to be used. Seems like the change over was only 1/2 done.........Thank you for a little ignition 101 tutorial. Hopefully, I actually grasped your clear explanations and actually worked this out. Now, if I am right, I just need to decide if I should take the gamble.

 

[Fundctr]

I have had the 57 about 4 months. After reading threads about the Pertronix 1281, and decided to buy one and mate it up with a Flame Thrower coil. Learned one lesson-Received new stuff, removed distributor cap...There is a Pertronix 1281!! However, it is hooked up to a stock coil, which is hooked up to the resister right next to it. The threads, and parts suppliers, led me to believe that the "hotter" coil was needed. However, maybe that's not really so, as the car is running. Anyway, the instructions for the 1281 and Flame Thrower contradict each other. The 1281's-keep the resister. The coil's-by pass it. The coil is 1.5 ohm, and I think that is what the resister is too.
So, can I just leave the wiring set up as is, and attach the Flame Thrower coil exactly as the current one? The reason I thought this might be necessary is there are two wires leading from the top connector on the resister (I assume power out). One goes to the carburetor, the other looks like it goes to an electric fan that has been installed on the front of the radiator. I felt if I by-pass the resistor, that would negatively impact the those hook-ups as it think it would cut off power to those two wires. I called tech support at Pertronix, they are closed until Monday. Thought I would try here. I guess I could leave well enough alone. Just thought there could be a benefit to the hotter coil. If I can hook it up just as the stock, that would be perfect. As you might tell, I am below amateur when it come to electrical issues.