Internal coil HEI to external coil HEI

Very famous guy who does custom build Dis for wacky applications was talking on TV [his name and show both escape me now.] that the performance epoxy filled internal HEI coils are junk. Because they cause more problems then they help from the heat build up. Which helps lead to early module failure.

As epoxy filled coils trap heat internally.

He recommends external oil filled can coils which will give you a quality spark up to any RPM.

Is there a kit to do this? Just so it looks nice, some kind of adapter kit for the stock connectors???

 

Lots of GM HEI have been running around with those "junk" coils for decades without failing or causing module failure. So, not really junk after all.

The HEI's with the coil in the cap do have a greater tendency to retain the heat since they sit inside basically a plastic box. The later style HEIs with a divorced coil are better for heat dissipation, being open to air circulation, but they're usually mounted down on the intake manifold which is probably hotter than up on top of the distributor cap, so possibly a "6 of one, half dozen of the other" kind of situation.

I would talk with coil manufacturers about what an acceptable "oil-filled can style" coil would be to work with the stock GM module (which must be retained, obviously, unless you're going to an MSD box or similar). The stock ignition system (module) was designed around the stock coil so I imagine just throwing an old points-style coil on there might cause it's own problems.

Wiring it up is easy. Just watch which wires inside the cap go to which pole on the coil and the module and re-create that wiring system exactly but on your new external coil.

Positive pole of the coil gets attached to the full 12V+ power lead coming in from the wiring harness and there is also a power lead coming from that same terminal down to the module to power it.

Negative pole of the coil gets attached to the "Tach" wire of the wiring harness to drive your tachometer and there is also a lead going down to the module.

The 3rd wire on top of a stock HEI is a ground wire but I don't beleive it will need to be hooked up in any way. In the stock distributor it is used to ground the metal armature around the stock coil, which an oil-filled coil won't even have.

 

Hi, we're putting together a friend of mine's electrical system in he's Camaro 89 5.7 TPI from scratch. We don't have any connectors or what so ever....
Could anyone please tell me what pin does what on the ignition coil. It's a external stock replacement coil, Accel.