GM HEI on Mopar,Does it work?

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1BadDodge71

1BadDodge71

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Hi everyone(again,Lol)I know I recently posted a thread about my points to electronic ignition conversion for my Duster and figured it out,but on AllPars,I came across this article on using a GM HEI and wondered if anyone has done this?I dont want to bastardize a Mopar with GM parts,but after studying it,it looks so much easier than wiring it for the Mopar ECU,ballast,etc.Plus it looks like it eliminates the ballast resistor.Let me know your opinions since I happen to have a GM HEI module just laying around.It claims the HEI gives a hotter spark.

http://duster318.freeservers.com/tech/hei.html
 
HEI works but it's not really much better than a standard Mopar ign box. The chrome Mopar box is at least as good if not better than a stock HEI. You can upgrade the HEI to make it better but in stock form they will start misfiring above 4500-5000 rpm. I saw a test that showed on a oscilloscope how the HEI was supposedly much better. I questioned the person that posted it as to what reference level the O-scope was set on for the tests and were the parts run of the mill parts or what. Never got a reply. For what it's worth I ran a bunch of GM's back when I was young and I will admit HEI is pretty reliable, but no more reliable than a Mopar electronic system.
 
You can't elminate the ballast resistor by just changing to the HEI module, you have to use a coil designed to operate without a ballast, but you can use a coil designed to operate without a ballast with a mopar module too.

Internally the 4-pin HEI module is just an electronic switch the same as the mopar module, it by itself has no impact on the output of the igntion. The aftermarket modules for both HEI and mopar have the ability to vary the dwell time so they can protect the coil from overheating at low rpms and provide more stauration time to support higher rpm limits.

I don't see that the HEI is any simpler, they both require 4 connections. Two to the distributor, one for power and one to the negative side of the coil. Bypassing the ballast is going to be a function of the coil used.
 
dgc333 said:
You can't elminate the ballast resistor by just changing to the HEI module, you have to use a coil designed to operate without a ballast, but you can use a coil designed to operate without a ballast with a mopar module too.

Internally the 4-pin HEI module is just an electronic switch the same as the mopar module, it by itself has no impact on the output of the igntion. The aftermarket modules for both HEI and mopar have the ability to vary the dwell time so they can protect the coil from overheating at low rpms and provide more stauration time to support higher rpm limits.

I don't see that the HEI is any simpler, they both require 4 connections. Two to the distributor, one for power and one to the negative side of the coil. Bypassing the ballast is going to be a function of the coil used.
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All very good points.

And I just read the article on Allpar and find it funny how the guy says heat and moisture don't affect the HEI ignition. I guess he doesn't know the HEI module must be mounted to a heat sink or it won't last any time. On a GM HEI system the distributor itself acts as the heat sink. That's why it has heat sink grease applied to the module before installing it. So he's absolutely wrong about heat not affecting it. Plus how would the Mopar module be any less resistive to moisture than an HEI module?? That makes absolutely no sense as the Mopar module is sealed just as good as a HEI module.

I have found some other questionable information on Allpar in the past.
 
interesting thread here on HEI vs the Mopar module.
I have seem most of the HEI conversion threads, but have not made a change yet,

fishy68,,, what HEI upgrades do you recommend, any particular coil work well with HEI?

dgc333,,if I go with a Mopar system,, what are good coil options , with / with out a ballist resistor?

motor is ( will be ) a warmed slant six, I have a slant electronic / vaccum distributor, to start with, but I am open to suggestions there to.

thanks
 
All things stop working sooner or later and I would rather change that box along the road than a dist,and that box is small enough to bolt next to the other I always have a spare..and a GM dist.in a mopar ARE YOU ON DRUGS!!!:angry7::angry7::angry7: O and no one has ever proven that a GM ignition is hotter or better..ill spend that money somewhere else..thats what I think about it........Artie
 
my68barracuda said:
interesting thread here on HEI vs the Mopar module.
I have seem most of the HEI conversion threads, but have not made a change yet,

fishy68,,, what HEI upgrades do you recommend, any particular coil work well with HEI?

dgc333,,if I go with a Mopar system,, what are good coil options , with / with out a ballist resistor?

motor is ( will be ) a warmed slant six, I have a slant electronic / vaccum distributor, to start with, but I am open to suggestions there to.

thanks
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Well IMO your better off sticking with the Mopar electronics but to answer the question the biggest problem with the HEI is the module itself. It just wont' fire good at high rpm (meaning over 4500 rpm). The stock coil isn't bad but if you want to upgrade it I'd go with a MSD. They make replacement coils that are a direct bolt in or a kit that relocates the coil to the fender/firewall/engine, basically wherever you want to put it. To me that kinda defeats the purpose of the design of the HEI which is to incorporate all the parts within the dist. One other upgrade that's really needed with the HEI is to use the best rotor you can get. HEI does have a lot of voltage and it's common to see no spark because of a hole burned through the rotor.

godfatherofchry said:
All things stop working sooner or later and I would rather change that box along the road than a dist,and that box is small enough to bolt next to the other I always have a spare..and a GM dist.in a mopar ARE YOU ON DRUGS!!!:angry7::angry7::angry7: O and no one has ever proven that a GM ignition is hotter or better..ill spend that money somewhere else..thats what I think about it........Artie
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Ain't that the truth. I have had to change the GM HEI module along the road side and it sure isn't very easy since it's located inside the dist. The Mopar module can be changed in just a couple minutes without climbing on the engine and laying accross it for 20 minutes with all kinds of sharp crap poking you in the ribs like you have with a HEI.
 
You do not use the GM dist, you use a stock 73 and up electronic ignition mopar dist and simply splice the HEI unit in between the dist and the coil. There is no way you could even squeeze a HEI dist cap into a car with a slant, even if they made one.

I have always run MSD Blaster 2 coils on my slants HEI or not with very few problems.

Go to the local yard and snag the aluminum heat sink off a late modle truck/van, re-drill 2 holes and mount that along with a stock 4 pin HEI unit on your inner fender between your dist and coil. It will be cool enough there that you will never have to worry about it over heating and it will not stick out like a sore thumb.

As for the stock HEI units cutting out around 4500 rpm......daily driven slant six, cam/no cam, 1bbl, 2bbl, 4bbl....how often will it even get close to 4000rpm let alone 5000rpm?
I did the HEI swap in my 73 scamp with a mild 360 daily driver (when I say daily driver I mean it was my only car for years) and I never had any problems with the GM ignition other than your usual "time to replace this or that" tune up parts. If anything I have had less ignition issues after I did the HEI swap on any of my mopars. I was trying to keep my 73 Dart stock but I am going to HEI it this week!

Just paint the HEI unit hemi orange and put a mopar sticker on it and mount it on the inner fender that way the mopar only gestapo members wont be mad at you:-D:bootysha:
 
Guitar Jones said:
I much prefer the MSD to anything else. Spend the money once and be done with it.
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joesnow said:
I agree, Spend you time and money once. Buy a MSD, Mallory and don't worry about it.
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only problem with them is when they **** the bed when i'm out in the middle east bumblefuck where am i picking another one up while sitting on the side of the road? too expensive to carry a spare. at least i can get a hei module i can get almost anywhere.
 
i have been using the hei for a couple years now on both my slanted valiant and my 318 poweragon. that is the best upgrade i ever did. hotter spark than the mopar unit, fewer components to worry about, and i can get the module everywhere. any of the aftermarket ignitions, be it pertronics, msd, whatever, the parts are not avalible at mom and popps parts store. even the mopar unit might not be on the shelf. the hei is. as far as thr revs, they have upgrade units that will let you rev much higher, plus in the slant that is a non-issue as the rev limit is acutaly 33% higher in a six cylinder. since running the hei, my car, and truck, fire right up, run better, and pass smog EVERY time. i am running a msd blaster coil with no balast resistor. using an old computer heatsink on the truck and made a heatsink that bolts to the alt bracket for the six. thay have lasted thru two summers here in the vegas heat. i am sold on the hei over mopar ignition
 
powerwagonpaul said:
i have been using the hei for a couple years now on both my slanted valiant and my 318 poweragon. That is the best upgrade i ever did. Hotter spark than the mopar unit, fewer components to worry about, and i can get the module everywhere. Any of the aftermarket ignitions, be it pertronics, msd, whatever, the parts are not avalible at mom and popps parts store. Even the mopar unit might not be on the shelf. The hei is. As far as thr revs, they have upgrade units that will let you rev much higher, plus in the slant that is a non-issue as the rev limit is acutaly 33% higher in a six cylinder. Since running the hei, my car, and truck, fire right up, run better, and pass smog every time. I am running a msd blaster coil with no balast resistor. Using an old computer heatsink on the truck and made a heatsink that bolts to the alt bracket for the six. Thay have lasted thru two summers here in the vegas heat. I am sold on the hei over mopar ignition
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run for cover!!!!
 
I've run the HEI setup in my /6 duster for the last 3 or so years with only one issue. It likes higher voltage like in the 13.5-14.0 range. I did convert to the 12v epoxy style coil. I will say that on my slant, it starts and idles better...I run an aftermarket module so it's not "GM" per se, but it's no different than adding any other parts made in china :lol:
 
I run the "better quality" (translation: higher cost) NAPA HEI with an Accel "stock replacement" distributor (Mopar style pickup/ reluctor) and NO ballast. IT does NOT give up at 5500RPM, it's STILL cheaper and smaller than a Mopar, and easier to deal with wiring. I'm not sure of the origin of my stock--type coil, but I do NOT run a ballast.

I ran a Mopar ECU in about 73 right after they first came out---had a 340 swapped into my RR body. Ran it for a long time, but this was BEFORE the Chineseo replacements flooded the U.S.

In conclusion, my main motivation was simplicity and the poor quality of many parts-store Mopar ECUs
 
You are using a "foreign" part in your Mopar, the purists will be by shortly to deal with you....
 
Not sure if this helps but our Daisy got an electronic dizzy conversion. Off with the points dizzy and on with a cheapy chinese HEI dizzy (with the module in the side). Before installation I repleaced the China mopule with a Bosch BIM024 module and she runs super sweet.
However without also changing the ignition coil to a HEI coil and bumping the plug gap up it was not really a HEI conversion.
I also wired in the coils power seperatley to the OEM loom, thus giving it full power at all times and bypassing the ballast resistor.
This option was VERY cheap, does the job well and can be put back to full Mopar spec at anytime.
 
What the heck is a Bosch BIM024? is that a replacement HEI module?
Google is scattered with various info on the unit so I thought I would ask.
It appears to be a full feature module with dwell and amperage management built in. Seems great.

Could you expand on how it applies with a stock mopar distributor? Could you recommend a coil to use with it? How does it operate at high rpm?

Thank you.
 
JR:
As for the stock HEI units cutting out around 4500 rpm......daily driven slant six, cam/no cam, 1bbl, 2bbl, 4bbl....how often will it even get close to 4000rpm let alone 5000rpm?
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My engine sees a smooth 5000 rpm all the time with the orange box. However a lot of folks are running the GM HEI over on slantsix dot org.
 
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