Installing a GM HEI Module

[Bewy]

Kevin,
You will find wiring examples on the net. Some people mount the module on a heat sink, onto the dist body.
Post #24 has an error in it.
Do NOT use a CD coil with HEI; it will misfire or not work at all.
To get the best out of HEI, use a dedicated HEI E core coil such as the MSD #8207. Use 0.060" plug gaps. If a stock coil is used, the bal res must be used with it & any coil that uses a bal res must retain the bal res, unless the instructions with it say otherwise.

 

[Dave999]

standard dizzy
you will need to work out which way to connect the pickup it only works one way properly
use a transformer/ laminated core coil and a short spark plug lead as your king lead
the coil from a ford or chevy truck 6 cylinder 1975 works well they are about $25 on rock auto
1976 CHEVROLET K10 PICKUP 4.1L 250cid L6 Ignition Coil | Shop Now at RockAuto
plug gaps 45 thou
pointless spending on a race canister style coil when the OEM frame coil does a better job

 

[ValiantKevin]

1. Yes it replaces both.
2. If you use the same coil you still need the ballast resistor to reduce the voltage so it doesn't overheat.

Better off to do the HEI module and a C, D or E core coil, as they are made to use a full 12v.
You'll also get the full benefit of the HEI spark, which allows up to an .050 gap on the plugs.

In a bit here I'll try to post some more info on that for you.

ADDED:
One of the cleanest of the HEI coils I have used is this 94-97 Dodge Ram truck coil.
It runs on a full 12v and does not require a ballast.
It also put out a spark almost 2x what the old canister type does, and is close to half the size of a canister coil.
You can either get the pigtail for it, or do what I did and trim the connector section off and solder direct to the terminals.
These coils work perfectly with the 4 pin or 8 pin HEI modules.
The 4 pin modules like you normally see used are a bit messy in my opinion, and don't have weatherproof connectors like the 8 pin module.

The last picture is my own car using the GM HEI coil and 8 pin module with weatherproof connectors.
I also have the wiring diagrams for all of these combos when you are ready.

View attachment 1715237053

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So basically what I was looking to do is I've got these I took off one of my others cars before I sold it, older but I know it works, have a new Jacobs electronic ignition module to make my dizzy electronic and Jacobs flame thrower coil.
At the same time, the setup @TrailBeast shared above looks pretty clean, more modern, possibly more reliable, and definitely more suitable for potential parts replacements... BUT this Jacobs setup worked very well and I already have it so I may just send it!

 

[Hankrebel]

My son and I did as @TrailBeast said and took a trip to the pick a part and picked up the whole set up, coil and module and all the plugs. It turned out really clean, just be careful of the polarity of the 2 wires from the distributorMy 71

My 71 318 Dart still has the dual points and I want to convert to electronic after it has left me stranded. I think it was the ballast but not certain.
What vehicles did you pull the parts from? I have a part yard local to me and will go looking for everything for a clean setup and stock connectors.

 

[Calipag]

My 71 318 Dart still has the dual points and I want to convert to electronic after it has left me stranded. I think it was the ballast but not certain.
What vehicles did you pull the parts from? I have a part yard local to me and will go looking for everything for a clean setup and stock connectors.

Reach out to @TrailBeast he is the expert. I just did what he told us to do and it's been bullet proof.

 

[BillGrissom]

My 71 318 Dart still has the dual points and I want to convert to electronic after it has left me stranded. I think it was the ballast but not certain.
What vehicles did you pull the parts from? I have a part yard local to me and will go looking for everything for a clean setup and stock connectors.

Many posts. Easiest and best is the GM 1985-95 (trucks, to 93 cars) HEI termed "small cap". The 8-pin module is inside the distributor. Take it, the pickup connector (cut wires right at sensor), the ignition coil and cable that connects the two, power connector/cable to coil (cut wires as long as you can), and the connector for spark control. The later is only used with some engine controllers (ex. Holley Commander 950 w/ adapter). Without the control input, it will spark at a fixed time (10 deg before trigger signal, I recall).

A Mopar e-distributor will trigger the module, but need correct polarity. Verify by spinning the distributor by hand with a timing lamp over a wire to a spark tester flashing. Verify it flashes (sparks) when the Mopar reluctor wheel teeth align with the mag pickup.

For more fun, while picking take the GM knock sensor (1-wire) and its module/bracket. It gives a simple 5 V "on" signal if it senses knocking. The sensor screws into the block drain plug (bushing adaptor if a slant-six). Much fussing about sensors, but consensus is "should work" since GM used the same PN on both V-6 and V-8 engines, though might false trigger if solid lifters. Some engine controllers (ex. Commander 950) can respond to the knock signal.

 

[Bewy]

The GM 4 pin module is MUCH easier to wire up & will do everything you want. See post #27 for the diagram. You can buy new modules for $15, so for $30 you can buy two, & piggy back one as an in-situ spare.
If a canister coil is going to be used, it will need to keep the bal res, unless the coil maker states otherwise. If using an E core coil [ good idea, more spark energy ] such as MSD #8207 or Summit # SUM-850500, you do not need the bal rel.

One of the pick up wires on the Chrys elec dist will be black. It connects to the 'G' terminal of the module.

 

[BillGrissom]

The GM 4 pin module is MUCH easier to wire up & will do everything you want. See post #27 for the diagram. You can buy new modules for $15, so for $30 you can buy two, & piggy back one as an in-situ spare.
If a canister coil is going to be used, it will need to keep the bal res, unless the coil maker states otherwise. If using an E core coil [ good idea, more spark energy ] such as MSD #8207 or Summit # SUM-850500, you do not need the bal rel.

One of the pick up wires on the Chrys elec dist will be black. It connects to the 'G' terminal of the module.

Not easier. The 8-pin has a GM cable that runs from module to GM coil so just plug and play for that connection, and designed to work together. The connectors are weather-proof Metri-pak, much better than the exposed spade terminals (type 57?) of the older 4-pin module. The megasquirt site has info on many different ignitions to retrofit.

 

[Bewy]

If the 8 pin module has 4 more 'pins', it has 4 more areas that can fail. The 4 pin module is the easiest, simplest to hook up & it will do everything the OP wants. You cannot get much simpler than post #27.

 

[BillGrissom]

If the 8 pin module has 4 more 'pins', it has 4 more areas that can fail. The 4 pin module is the easiest, simplest to hook up & it will do everything the OP wants. You cannot get much simpler than post #27.

Photo of 8-pin HEI in my 1964 Valiant slant (R inner fender). The HEI module is at top right and GM e-coil to left of it. Only 4 of the pins are required, the other 4 pins are for the option of a spark timing command. I'm not currently using that, so have a connector w/ stub wires on to keep it clean. That connector can be used with an engine controller (TBI or MPFI), but I currently have a BBS carburetor. Readers should view this thread, post #2 by Trailbeast who used to sell a kit for the 8-pin module. I recall posting about the 8-pin module on FABO before Trailbeast stepped up to help. Not my idea, rather read of it on the megasquirt site.
a Frenchman who needs advice for GM HEI MODULE!!!!

Allows a clean installation with sealed connectors. I mounted the module on an alum fin heat sink (old PC chip cooler cut to size). The GM cable from module to coil makes it simpler. The white wire off the coil is for a tachometer (not using). Readers are likely interested in photos of your HEI setup to judge your "simpler" claim. Same number of pins to wire in both, but easier and cleaner using factory GM connectors and cables. Can snicker as you deviously snip wires on a salvage yard Chevy.

For those interested in other things in the photo, I mounted the Vreg near the alternator for simplicity. I added a water valve to block heater coolant flow when the AC is ON (wire from under-dash knee-knocker). Not essential since the cabin blower only runs when heating. You can barely make out a Chevy filter w/ return to tank below the distributor. The return drop builds ~5 psig, which is enough to supply the carburetor after an inline pressure-reducing regulator (Mr. Gasket dial-wheel type). Required because I have an EFI fuel pump which cannot be dead-headed (requires bypass return). That allows for later EFI fueling if I get there before I die. I can swap in a Corvette Filter/Reg in place of the simple filter (same footprint and fittings), which regulates at 56 psig.