HEI ignition conversion

Newport 66

Old Man with a Hat
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Anyone convert their point system ignition to HEI? Please educate me and pass along your experiences. Thanks
 
Why? Tissue rejection possibilities?

The DUI HEI items can be a good alternative that has its roots in OEM performance criteria, vs an aftermarket-only system. BTAIM

There is no real need to have the capabilities of firing a .100" gap plug, which was an original OEM HEI design goal. Only thing is that past .060" gap, plug wire integrity is supposed to be an issue. Advances in spark plug designs/materials have seemed to decrease the need for such a wide gap in order to get the mixture to fire off well. Use an NGK Iridium plug at .040" and you'll get a better "fire off" than most specialty plugs, from what I saw on a YouTube video of spark plug designs being compared. Both on fuel efficiency/run time and in watching the spark plug fire the mixture through a thick layer of plexiglass on a flat head motored electrical generator.

Any GM technician, who was around when the HEI was in production, knows that it has a few quirks in its design, as the miles on the distributor accumulate.

1) The module has to have some dielectric grease under it to serve as a heat sink promoter so the module does not overheat and fail.
2) In some cases, the advance weights can stick and cause performance issues
3) The carbon contact between the bottom of the coil and the center of the rotor can wear out and be "lost". The coil will still fire, but when other things get worn too, the engine can stopo "for no reason". Not unlike an over-heated module on that dark stretch of road at night.
4) The module can fail from age. One day I had the cap off of the HEI on my '77 Camaro. I barely touched the top of the module and the center section moved. Had to call a wrecker as it didn't run. IF I'd suspected it needed a module, I could have easily fixed it myself.
5) That big cap consumes a good bit of real estate under the hood. In some cases, it can affect air cleaner choices.

On the other hand, as things have progressed, the DUI HEI set-up is based on a validated OEM design system which can offer outstanding durability. The HEI was GM's third venture into electronic ignition systems. First was the CD ignition in the middle '60s, followed by a pre-HEI system on Pontiac V-8s in 1972. With HEI appearing late in the 1974 model year on Chevy V-8s.

There are some electronic boards which can replace the OEM electronics to allow for multi-strike capabilities, which can be good in some cases.

It probably won't affect performance any, but a GM distributor under the hood of a Chrysler product just doesn't look right, to me. Even with the advantages of the DUI HEI system. BTAIM.

And, like parts for a small block Chevy, repair pasts can be everywhere at decent prices, including the upgraded items from the aftermarket.

Just some thoughts,
CBODY67.
 
I just bought an HEI for the 401 in the Gremlin. Been using a Petronics conversion and have not liked it. Have not installed it yet so I can't comment on how I like it.

I did read that you are not supposed to sue a ballast resistor on one. Talking with a local mechanic about that he said the Petronics is not supposed to use one either. We have been since we built the motor; he said that's probably why I have not liked it. Oooops!!
 
Good part is the module is cheap and small for glovebox storage for spare. Replacements are readily available at any chain parts store (yes it's a Chinese POS, but beats walking), Mopar ECU will get you a blank look from anyone under 40, and a we can have that tommorow morning, "yeah thanks it's broken now, not tommorow". Not a bad idea in today's world, or you can put a petronix in it and wait for the UPS man to bring your replacment parts, make sure your AAA membership is paid up.
 
The HEI upgrade for GM vehicles was almost as "approved" as the MP Electronic Ignition kit was for Chrysler people. All it takes is one 12v switched power wire. Also has a tach terminal, too. Drop it in, hook it up.

I believe that the original HEI module (from GM) is supposed to have some sort of variable dwell mechanism in it, but I've not seen that in "the light of day". All in the optimization of the spark production itself. Some aftermarket units make similar claims, as if their unit is the only one with that feature.

Another neat GM/Chevy pickup item that can be paired with the HEI is the stand-alone detonation sensor. The sensor screws into the rh block drain plug, the "box" mounts inside the vehicle, and connects to the HEI module designed to accommodate the system. Any mid-'80s Chevy V-8 pickup with the "Electronic Spark Control" plate on the tailgate has this system. ONE thing we found out was that it can be subject to RFI. An oil field company truck came into the service department with the complaint that whenever the driver keyed his FM-band business radio (probably boosted a bit?), the engine would falter and die. Hearing that and the fact that nobody knew what was happening, I headed for the break room's refrigerator freezer. I found some aluminum foil there, enough to shield the case of the detonation limiter's control box from the powerful RFI of the company's radio. Fixed! Everybody smiled, including me.

Most parts of that system have long-been discontinued from GM, so it's a salvage yard item now, IF any are still around.

Enjoy!
CBODY67
 
I put together a 64 Galaxie with a 460 a couple years ago. The MSD module quit after a few hundred miles.
My neighbor convinced me to get a $40 HEI ready to run deal off Ebay, since he used one with success on his jet boat.
It worked flawlessly the whole time I owned the car.
That thing would fire right away, every time.
 
It works really well, I still have the parts for it. I just didn't want to mount a coil upright to run it, so I installed a Mopar electronic ignition in my'66. My Newports running a FBO box so the HEI is a moot point for me.
From what I've read, an E core coil is the way to go. Those are usually potted with epoxy and not oil filled. The E is the shape of the windings.

But, if you really wanted to keep a canister style coil, I would try an epoxy filled one with a real low resistance primary. I think Pertronix sells one. It won't perform as well, but I'll bet you won't notice the difference unless you started running some large plug gaps
 
S
I just bought an HEI for the 401 in the Gremlin. Been using a Petronics conversion and have not liked it. Have not installed it yet so I can't comment on how I like it.

I did read that you are not supposed to sue a ballast resistor on one. Talking with a local mechanic about that he said the Petronics is not supposed to use one either. We have been since we built the motor; he said that's probably why I have not liked it. Oooops!!

Scott, I don't know if you remember my 68 Sport Fury, but I installed a Pertronix unit on it about 12 years ago and it has always run flawlessly with the ballast resistor in place as well. It has been so long now I honestly can't recall what the instructions said but I followed them when I installed it and 12 years later it is still running perfectly. Thank goodness!
 
I converted to the GM module using a mopar performance electronic dizzy and an aftermarket 60kv E-coil. easy, runs great...no complaints.
 
S


Scott, I don't know if you remember my 68 Sport Fury, but I installed a Pertronix unit on it about 12 years ago and it has always run flawlessly with the ballast resistor in place as well. It has been so long now I honestly can't recall what the instructions said but I followed them when I installed it and 12 years later it is still running perfectly. Thank goodness!
I do; that was a nice car. I remember your Superbird too!! :thumbsup:
 
I'm running a stock electronic distributor and pickup coil with an HEI module mounted on a piece of aluminum on the core support with a MSD blaster coil mounted next to it. I has been a good setup and is something I have always wanted to try.
As to the comment on availability of HEI modules don't bank on that. If it was the 90's I would agree. There are 6 parts store between 3 chains on my nearest main drag. There was 1 HEI module available and nobody behind the counter knows the difference between that or fairbanks and morse magneto.
Carry a spare.
 
I'm running a stock electronic distributor and pickup coil with an HEI module mounted on a piece of aluminum on the core support with a MSD blaster coil mounted next to it. I has been a good setup and is something I have always wanted to try.
Carry a spare.
mine...totally removable if I ever want to change back.

20190905_154716.jpg
 
I'd like to try this HEI modification. Can someone recommend a good quality U.S. made electronic distributor. TIA.
 
I'd like to try this HEI modification. Can someone recommend a good quality U.S. made electronic distributor. TIA.
Yep, have @halifaxhops sell you a rebuilt distributor. The old ones are better than anything new. That applies to just about everything.
 
The biggest thing with a distributor is get the right curve in it. You have to watch the aftermarket curve that they will work for your combo. Watch the parts store replacements they cover usually ten years of different curves and are kind of set in the middle. Nothing wrong with good points they last 10K miles usually. I do like the HEI conversion but carry a spare module. The petronix I seem seriously reliable also. Just FYI
 
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