[69ZL1]

If you are running and a Acell super coil you should also be running a matching module.
If you are running a stock GM module, it does not like the higher voltage that the Acell super coil put out, they usually don’t play well together for long.

All coils put out the same secondary voltage, just enough to cause the plug to arc-over, and then that secondary voltage is essentially clamped when the plug current starts flowing. The plug gap size and cylinder compression pressure are the two main determinants of what that arc-over voltage ends up being.

An OEM HEI module has multiple protection circuits built into it, so it's a pretty robust piece. I'm curious what specific (non-marketing) electrical specs distinguishes the super coil from production coils. If anyone knows, my engineering curiosity would appreciate it.

 

[RPS]

https://www.holley.com/products/ignition/ignition_coils/street_and_strip/supercoil/parts/140003

They refer to a Standard Products part number... I'm thinking it's a more or less stock coil with a fancy cover for triple the price.

 

[Travisp33]

https://www.holley.com/products/ignition/ignition_coils/street_and_strip/supercoil/parts/140003

They refer to a Standard Products part number... I'm thinking it's a more or less stock coil with a fancy cover for triple the price.

Yea, I don't disagree - which I why I started the thread asking if it was any good. If the coil was shot I would have gone Davis Unified. I'm not sure their complete solution is any cheaper, but I do think it is better.

 

[658Chevy]

Looks like NAPA is also getting in on rebranding greed:

This is on NGK's website:

The reviewer is right -- same NGK brand, same NGK part number, 1/2 the price direct from NGK.

 

[mr 4 speed]

I think it’s been over 4 years since I installed the $50 EBay HEI in the 69 SS396
Even ran a 12.16@111 mph on 87 octane (8.9:1 compression) with it.

Racing Chevy V8 HEI Distributor w/ 65K Volt High 9000RPM | 350 454 SBC BBC GM08 | 350454SBCBBC | DD-Sbc-Hei-V8

Applications include 262, 267,305, 307, 327, 350, and 400 small blocks, 402 and 454 big blocks. Ready to run. 1976 Chevrolet Monza 4.3L 262C V8. 1975 Chevrolet Nova 4.3L 262C V8. 1980-1981 Chevrolet Camaro 4.4L 267C V8.

www.ebay.com

 

[temp2c]

Speedy Tip
-We recommend using our lock plate, part number 91012339. This will keep the timing steady without any flutter that the vacuum advance can cause.

I just used one of those on my HEI and I'm amazed at the difference in performance. Setting timing is also easier without the line going all over the place.

 

[71350SS]

Any thoughts on the 3 corroded\burned terminals?

Those corroded terminals are the result of not using any or enough dielectric silicone grease when the spark plug wires were installed.

Permatex® Dielectric Tune Up Grease, 3 OZ - Permatex®

www.permatex.com

I bought a 3 oz. tube of this maybe around 2004 and still have the same tube. So even if it costs $6.99 over the years it only costs about $1 or less a year.
Using the silicone grease allows you to make sure the plug wire ends will snap down securely onto the distributor cap. Because even a small amount of looseness in that plug wire to cap can allow the HEI to jump that gap and cause that corrosion.
I'd be interested to see what the plug wire ends that came off those three terminals look like.

 

[imaginationuninc]

As others already pointed to, the corroded terminals suggest gaps the voltage had to arc over.

It's akin to problems I experienced on both a Honda Accord and a Chevy Astro cargo van. Both started eating rotors and caps in just months, rather than years. Several sites pointed to worn distributors, but didn't say why, so I pondered it and came up with the why, which applies here.

Coils hate change. That's a good thing, because that's how they work. More specifically, they oppose change in current, which happens when breaker points or other systems open the circuit to the coil.

To fight the change, the coil voltage keeps raising. Eventually, it jumps the little gap between the rotor and distributor cylinder contact points, AND across the plug.

As the distributor wears, the system gets monkey wrenched. For example, the gear teeth on my Astro could have cut meat. They should have been more like poorly designed hammers.

This, of course, meant slop. That is, instead of the coil firing when the distributor gear had the rotor at the plug terminal in the distributor, it was off.

This meant a big spark gap in the distributor, wearing at the contact points.

Too, this meant that coil voltage was climbing higher than the system was designed to handle, resulting in corona on brand new, quality plug wires, and even the coil. That can't have been good for the coil.

A swap of the distributor and the rotor and caps went back to lasting years, instead of months.