Engine Will a newer TFI coil work in a Duraspark II system

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Oct 4, 2020
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Thinking of using a newer TFI coil in my 83 Duraspark II ignition system... Has anyone tried this before or had experience doing this??
Some say it will work and others say the TFI coil works on a full 12 volts while the duraspark system has a red/resistor wire that reduces the voltage??
Thanks
 
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Thinking of using a newer FTI coil in my 83 Duraspark II ignition system... Has anyone tried this before or had experience doing this??
Some say it will work and others say the FTI coil works on a full 12 volts while the duraspark system has a red/resistor wire that reduces the voltage??
Thanks
Duraspark wiring
Note the ballast resistor shown in the diagram: you’ll need that too
DuraSpark wiring.JPG

If you use a coil from a 78 or later Mustang, you don't need the ballast resistor. The stock 89 Ford/Mustang ignition coil does not need a ballast resistor

A simpler HEI ignition that uses the same distributor and fewer parts can be found here. This is an excellent resource, and I suggest that you add it to your Internet Favorites
 
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The main reason I want to use an TFIcoil is I have to move the stock coil mounting from the intake manifold ( due to a newer carburetor).. Seems to me a stock TFI bracket and coil would bolt right up as they do to a newer car that comes with the TFIcoil...
 
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FTI coil?
Never heard this term, TFI or E core maybe?
I run a E core on my 69 with a Duraspark no problem
40kv instead of 20
Senility grabs my brain sometimes....... TFI is probably correct.. Whatever the coil is that was mounted to the drivers strut tower, not the can coil on the intake manifold.... 86??
Whats an E core?
 
Duraspark wiring
Note the ballast resistor shown in the diagram: you’ll need that too
DuraSpark wiring.JPG

If you use a coil from a 78 or later Mustang, you don't need the ballast resistor. The stock 89 Ford/Mustang ignition coil does not need a ballast resistor

A simpler HEI ignition that uses the same distributor and fewer parts can be found here. This is an excellent resource, and I suggest that you add it to your Internet Favorites
I am an old Chevy guy and I would have loved using an HEI system but, the HEI interfered with the stock Air cleaner......
 
They (Ford) calls the newer coil an E core is all
It's Just the shape of the core that the windings wrap around
I don't believe I am running the factory resistor wire or other ballast with my e core
It's a 12 volt coil
 
I hate to say it but that HEI set up is hard to beat for a carb car, now about that coil thing, I understand what you want, the square (E) coil would look better than the can coil on the shock tower, if the E coil can be used with the Duraspark ignition is the question I can't answer.
 
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We've tried using the "E" core coils with the Duraspark II and found out after one or two higher rpm hits, the module overheats and pukes the potting out. Leaves a big mess when they do that. I've heard of others having good luck using the newer coil with the Duraspark also. I'm thinking it's rpm dependent. The more rpms, the more amperage the coil pulls. If it's just a daily driver that will never see any kind of rpms, you may get away with it. Now this is only based on my experiences and like I said, others have had different results, but I do not know exactly how those cars were driven.

Also, the Duraspark gives you a retard of four degrees when cranking, which is helpful when you want to run a little more base timing. I have found only the Motorcraft and top line Napa modules have this feature.

Or, why not run the canister coil on the fender well?
 
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It truly is amazing when you change something how involved it can get....LOL
1. From my " understanding" the reason for the resistor is so you do not overheat and burn up the oil in a Can coil...
The "E" coil does not need a " resistor" for that reason...
2. IF I move the coil to the strut engine compartment area, the E coil should be a bolt on and would look cleaner, in my opinion....
3. NOT an electrical whiz but the numbers I found were 10-10.5 volts? reduction thru the resistor wire to coil.... I could remove or by pass the resistor wire, but would prefer not to.... I would not think that it would effect the coil much for my grocery getter..
4. Cam was chosen for a max of 5500 rpm, so I do Not plan on revving the engine very high.....
5. I guess if I installed one and it didn't work I could go back to the can coil..
6, I will look into mounting a can coil on that drivers side intake manifold hole two.. I spent some time cleaning and painting the can coil mount, but the coil will be replaced as this one is really rusty and worn looking...So I will need to buy one or he other eventually.....
 
It makes no sense to me
The coil would pull more amps when at high RPM on a Duraspark?
Mine has been running 12 volts on an e core coil since the late eighties
True I have burnt up 2 modules (over 40 years) but I am running used Motorcraft ones anyway
My 69 has 456s (high rpm is a yes)
 
We've tried using the "E" core coils with the Duraspark II and found out after one or two higher rpm hits, the module overheats and pukes the potting out.
Yes, and DuraSpark-II uses a higher-resistance looil for that reason. The DS-II is not designed to flow that much current, and will often overhat the module. However, the high-energy DuraSpark-I (red grommet, came-out after the DS-II, and is HEI-equivalent) is designed for no resistor and with low coil ohms. It outputs more energy and up to higher rpm.

I would suggest either a correct-ohm coil (±1.5-ohm) with your DS-II, or change-over wiring and box to DS-I with a TFI or similar coil, or to HEI module (GM or MOPAR) and TFI coil, etc. Using various parts in-combination is fine, but the types and ratings must match for both power and reliability. BTW, many think they have no ballast or resistor, as in all Fords up-to DS-I and TFI it is a pink wire under the dash (printed RESISTOR) that they never see, or heat-sleeved to know when they look at it. ;)
 
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BTW, many think they have no ballast or resistor, as in all Fords up-to DS-I and TFI it is a pink wire under the dash (printed RESISTOR) that they never see, or heat-sleeved to know when they look at it. ;)
Yes my car is supposed to have this. I think most people don't know about it because it is under the dash..
What I dont' understand is the TFI is designed for full voltage while its the Duraspark and the "can" coil that needs the resistor wire. Why would the TFI system need the resistor??
 
The resistor wire ran from the ignition switch to the coil
Not just under the dash (on all I have seen)
The wire had both rubber and cloth insulation
My original wire is long gone, as are most, as they burnt up regularly
I am doing some " repairs" to the engine wire harness, so I will trace that and check it out.... Service manual says its " under the dash "
Again, from what I have researched, the resistor wire was for the can coil on the duraspark to prevent it from burning up... The 86 up "TFI" gets full voltage to the coil, so I would have to wonder why there is a resistor wire in that system?
Anyone confirm that??
 
What I dont' understand is the TFI is designed for full voltage while its the Duraspark and the "can" coil that needs the resistor wire. Why would the TFI system need the resistor??
Confusion. The coil resistance must match the controller. Points, DS-II (blue grommet) do not control the dwell, and need both a resistor to the coil and a coil with 1 to 2-ohms resistance ("standard" coil).

DS-I, TFI and other high-energy systems control the dwell (current through the coil) electronically, so they do not need a resistor, and can use coils with 0.5 to 1.5-ohms resistance (HE/HEI/TFI coil).

If using DuraSpark, the color of the wire grommet will tell you what coil you can use, and if you need a resistor. This may help:

DuraSpark I & II wiring.jpg
 
There is no resistor in the TFI E core coil system (12 volts to the coil with the key on)
All the round oil filled coils are designed for 9 volts
The starter relay 2nd terminal disappears on the ones with no resistor
You know of course that the 2nd small wire bypasses the resistor and gives 12 volts too the coil when in crank?
What I did was simply use a 40kv E coil on my Duraspark with no resistor wire
Mine has been working that way since the late eighties