Quick HEI Question

[brandontyler65]

i have recently had the Duraspark 2 Box (retro-fit) go out on my 67 Mustang and i have an HEI module so i wired it up like so

and the module is getting 12V(13.4 to be exact) but the wire i was using to power the coil was the points resistor wire (9V or so) cause i have the original points coil will the GM HEI module work with the 9V at the coil i think it will but i don;t want to hook it up and fry it cause then i would have to spend money. and its not that i am cheap but i am a college student so money is tight

 

[onion]

Wow... you're ambitious. Personally, I think you'd be better off shelling out the money for a new Duraspark module. But you might be able to make this cobbled-up setup work if you have to.

What sort of coil are you using? Is it an HEI coil? Or the one that came with the old Duraspark setup? The module just opens and closes the coil ground, so it won't matter if the coil is only getting 9V.

I can't comment on your wiring diagram, but my main concern would be whether or not the pickup coil is compatible. I don't see how you could fry anything here so long as you've hooked up the module correctly. Worst-case scenario... it just won't start.

 

[TooManyWheels]

The GM HEI module requires the full 12 volts. When HEI distributors were retrofitted into traditional points-type cars, the resistor wire which reduced the voltage from 12 had to be bypassed. However, like the previous poster, I don't see why the coil would need higher voltage just because a module requiring a higher voltage was installed.

 

[Steve S]

Ever think of running a Pertronix unit? the digital series seems to work pretty good and easy to install.

 

[tom slick]

If it were me I'd run 12v to the coil but if the coil worked with 9v and the durasparkII system hooked up it should work with the HEI module.

 

[brandontyler65]

thats just to give you an idea of how its wired its a diagramn i looked up in the net. i have had the pertronix and it gets too hot here in az sitting in traffic i fried 3 b4 i gave up. so i wired up a DS2 and it worked good but now that has cooked. the module is getting 12 volt but the wire supplying the coil is 9v but i guess that you are right all it does is collapse the field so it will be no prob.

 

[onion]

How about an update? Did it work?

 

[OVERKILL]

It's a Mustang bud, upgrade the ignition! Put an MSD, Mallory or something box in it.

 

[Lazy JW]

The GM HEI module triggered by a Duraspark distributor firing either an HEI or Ford TFI coil is an excellent upgrade that can be done for cheap. Check out http://www.gofastforless.com

 

[brandontyler65]

i went to school and wired it up in the electronics lab and it works really good even with the original points coil i was stunned how much better it preformed than the Dura-spark in terms of dwell and the rise times. i am not saying the dura-spark is bad i do like the spark retard. i wish i could post the images from the oscilloscope. i had an MSD but i didn't like it i gave it to my dad and wired it up on the 460 and it passes emission no prob now. so it works good i cannot wait for a road test(won't be for a while though cause of school)

 

[mechtech2]

Whoever came up with this is pretty sharp [or cheap].

 

[Lazy JW]

Originally Posted By: brandontyler65
....not saying the dura-spark is bad i do like the spark retard....


I saw mention on another forum about a 5-pin GM module; supposedly similar to a 4-pin but had an additional input for a spark retard to facilitate starting. Never seen one myself though....seems like it may have been used on Cadillac ? A google search might turn up something useful.

I'm running the DS2/GM combo with a TFI coil on a 74 Ford. Works great!
Joe