Duraspark conversion.

[tw205]

So I’ve done two of these now and both run fine. I’m looking for input on some things I did to mine that were not mentioned in the tech section used when I took on these projects. When I did mine I chose to make my own wire harnesses as searching for an existing one proved futile. The first conversion, I went by the book on parts needed and it went without a hitch. The second one I decided to use the original coil instead of the one listed in the parts list. It fired up for a bit till the magic smoke escaped the ignition module. Researched causes and concluded either the module wasn’t grounded well or the absence of a ballast resistor caused the failure. A new module, grounded securely, and a ballast resistor were installed and I’ve not had any more issues, although I’ve only ran it for maybe 20 minutes, as it’s not a completed project yet. I went and installed a ballast resistor on the first conversion as well thinking it may release the smoke. My understanding is the duraspark pintos and mustangs used an inline resister incorporated in the wire harness. So I know some of you fellas will have insight for me if I’m right or wrong. And if a ballast resistor is needed we could add that information to the duraspark update @Jim Oaks is doing.
Aaand GO!!

 

[ford4wd08]

I would use the HEI module.

Very very easy to get running. You can leave all existing harness and then remove it once you have it running.

You just have to have 2 wires to the distributor and then the negative and positive side of the coil. So 4 wires total.

No ballast resistor needed and you can run the stock square tfi coil.

More info in my thread here -> https://www.therangerstation.com/fo...spark-distributor-with-hei-conversion.185317/

 

[tw205]

I think I read thru that while searching for reasons why my module smoked.
I would not be able to show my engine to any friends in fear they would see a GM part on it. My life would be over if they saw that. I would be mocked into isolation. Maybe if I put a FOMOCO sticker on it. My friends aren’t that bright.

 

[superj]

i understand that. none stop because of a chevy part on the truck.

 

[Uncle Gump]

Dura Spark ignitions ran an internally resisted coil if I remember correctly.

There would be no need of a ballast resistor if using a resisted coil. I remember the internally resisted coil we used on pointed ignitions were 1.6 ohms... without it would melts the points. Same kinda thing with Dura Spark but it is melting down a switching transistor on the module board.

 

[ford4wd08]

I think I read thru that while searching for reasons why my module smoked.
I would not be able to show my engine to any friends in fear they would see a GM part on it. My life would be over if they saw that. I would be mocked into isolation. Maybe if I put a FOMOCO sticker on it. My friends aren’t that bright.

They'll get over it when it runs great lol. Many aftermarket HEI distributors out there for Ford small block v8's.

Mine is just mounted to aluminum block or heat sink on the fender. I'm going to install my stock cover back over it at some point.

@RonD maybe you can convince him on the benefits of the HEI lol

 

[Uncle Gump]

i think the biggest advantage with GM HEI is you can use an un-resisted coil with the potential of 60kv. Dura spark coils are like a 40kv potential.

 

[tw205]

I’m not opposed to the HEI module. I was more looking for whys and whatfors. So assuming the parts listed in the tech section included a coil that is internally resistored would give reason to why I had no issues on the first duraspark. i Looked up the coils listed at autozone ( no tech info ) and Napa (says voltage 12v ). I’ve yet to solder up my wire harness so maybe I’ll check into HEI module before I commit. Thanks for the info guys. Good knowledge to posses.

 

[ford4wd08]

i think the biggest advantage with GM HEI is you can use an un-resisted coil with the potential of 60kv. Dura spark coils are like a 40kv potential.

Which means more horse powa from more spark

Kidding of course, probably helps the spark be more consistent.

Knock on wood, but I think I have my 2.8 running pretty good. Don't forget to set the lash on the valves, can make a big difference on these old engines.

 

[tw205]

Which means more horse powa from more spark

Kidding of course, probably helps the spark be more consistent.

Knock on wood, but I think I have my 2.8 running pretty good. Don't forget to set the lash on the valves, can make a big difference on these old engines.

Valves got adjusted yesterday. I installed new rocker arm shaft supports and a set of baffles.

 

[Uncle Gump]

Which means more horse powa from more spark

Kidding of course, probably helps the spark be more consistent.

Knock on wood, but I think I have my 2.8 running pretty good. Don't forget to set the lash on the valves, can make a big difference on these old engines.

High energy coils are kinda like big batteries with lots of CCA. You don't really need it... but it's nice to have it.

 

[19Walt93]

Duraspark modules are apt to fail if the coil resistance is too low. I used an external resistor and a low resistance coil I already had. Stock Duraspark will work great with .044-.046 plug gap and reasonable compression. My Mustang 302 is zero deck with Speed Pro pistons and GT40 heads and it runs Durapsark, too.

 

[franklin2]

Ford always used a resistor feeding the coil + terminal on stock duraspark II systems. When in Rome, do as the Romans do.

What you are doing when the ignition module completes the ground to the coil, is "charging" the coil up. When the module initially completes the circuit, the current through the module to the coil primary is very high. As the coil "fills up" the current steadily decreases. When the module opens the circuit, the "charge" in the coil dumps to the high tension side and travels down the sparkplug wire to the plug to create the spark. The resistor limits the amount of current that runs through the coil primary, which also limits the current through the module. Too much current through the module shortens it's life.

 

[19Walt93]

/\ /\ Like he said, Ford mostly use a pink resistor wire but a separate resistor added will do the same job and preserve the ignition module.

 

[4x4prepper]

I converted from TFI, to points, then when running correctly, then to duraspark II. Here is what I am using:

ignition coil
Accel 8140
AdvanceAuto 2018-04-08


Ign. Resistor:
BWD RU19
O'Reillys 2015-05-01