Choose a 12v coil and you won't need a ballast resistor.  I had Pertronix II with the matching FlameThrower II coil before installing the Duraspark II.  I kept the coil.

Rufus68 wrote:

Choose a 12v coil and you won't need a ballast resistor.  I had Pertronix II with the matching FlameThrower II coil before installing the Duraspark II.  I kept the coil.

Yeah my Pertronix Distributor is the Pertronix lll and requires the pertronix lll that has the Low  0.32 ohms. So I figured it may not work with the Dura spark.
 

Last edited by BILLY WALTON from GEORGIA (9/05/2024 8:45 PM)

I went digging through Rock auto and found a car with a Duraspark then bought the matching coil. It has give me no trouble, but it seems like the ignition is lacking to burn all the gas at idle and have been told to make the ignition hotter. I will swap the existing coil for what was used on the fuel injected 5.0 motors. Had the new coil for a while, but haven't took the time to install!!

Rufus68 wrote:

From everything I could read, I don't see how your .3 ohm coil could hurt the Duraspark II module since only the neg post of the coil is wired to the Duraspark module.  Since the coil you have will not overheat being connected to a full 12v input, I think it should work fine.  If this is false, I'd love to understand why for future reference.

Edit:  Pertronix list your Flame-thrower III coil at 0.32 ohm not 0.032.  I think it will work fine.
 

It says my Petronix lll coill is .32 ohms specifically designed to work with Petronix lll distributor says it wont even work with the Pertonix l or ll only the lll.
 

I would follow their instructions.  I've run their coil and Ignitor I for a long time with no issues.  I had an Ignitor fail when I left the key on for too long doing some testing.  I learned the hard way to disconnect the Ignitor if I need to do that.  It clearly says not to do it in their instructions, but I'd installed the Ignitor like 20 years before and didn't realize.  Point being, I feel Pertronix knows their products well and if they say don't do something I wouldn't. 

Based on what I read, I'd cancel that order and at least order the FlameThrower II.  The FlameThrower coil web page mentioned only the inductive ignition systems.

• 40,000 volts.
• Available chrome plated or black for that "stock look".
• For use with inductive ignition systems.
• 1.5 or 3.0 Ohm primary resistance values available.
• Legal in all 50 states and Canada. (C.A.R.B. E.O. #D-57-21)

• 45,000 volts.
• Available chrome plated or black for that "stock look".
• For use with inductive or CD ignition systems.
• Low 0.6 Ohm primary resistance.
• Legal in all 50 states and Canada. (C.A.R.B. E.O. #D-57-21)

Rufus68 wrote:

Actually, I'd run the FlameThrower III coil that you already have.  It should work the best with the Duraspark and give the hottest spark.

I will try it on there too.I am gonna put the Duraspark syatem on  and try it and if it runs good I will try the coil...just trying to do some eliminations on what may be causing my new engine to lack the power I feel it should have. read alot where the Pertronix coils and distributors fail....i did have the pertronix l conversion on my old car and never had a problem ...but something is going on for sure.

Last edited by BILLY WALTON from GEORGIA (9/08/2024 5:30 PM)

Rufus68 wrote:

The Internet is full of things to read giving all points of view.  And people post more often when reporting something negative.  I can see where your investigation into your engine performance can be very difficult without having real data to go by.
 
Imagining the number of Pertronix coils that are in use, That "large" number of failures might actually be a small percentage.  It is just impossible to know without accurate data.
 

That's my point of view as well.  There could be a million satisfied customers who never posted a review, but 10 failures where a disgruntled customer did make the product look failure prone, even though that's only a 0.001% failure rate.

Another thing you can never qualify is installation error.  That disgruntled customer is NEVER going to admit they didn't read the instructions, or did something they shouldn't have.  People it seems often feel a product should be good enough to not fail due to their own stupidity. 
 

When I converted I left the pink wire in the circuit.  I first used it with the stock coil that had been on it with the points.  It was OK but I decided that maybe it could be better.  So I bought a "Performance" coil.  It worked OK too but seemed about the same as the points coil.  But when I changed to a coil used with the DuraSpark on the Fords (mine's from a 77 Versailles), it made a noticeable improvement.  So I've stayed with that.