Could someone help me understand the difference between upgrading your points to an electronic ignition compared to installing a coil/ignition box

[Geoff 2]

Sinitro,

We could debate until the end of time about different igns & their reliabilty. I have seen people using dielectric grease under the HEI module......it fails....& then they blame the module!
I have TWO Chrys ECU boxes here where the sealing 'goo' in the back has become almost liquid & run out.

 

[Geoff 2]

The HEI is a vast improvement over the Chrys elec ign. 0.060" plug gaps, some had 0.080" gaps. Plus variable dwell which kept the coil cooler & extended it's life. The number of external connections were reduced, reducing the chance of a bad connection due to corrosion/looseness. And more spark energy due to the low pri resistance of ign coil. Plus, an E core that keeps the energy in the coil, not radiating into space as a canister coil does. A no brainer. I have run 0.125" plug gaps with HEI.

 

[440 PHIXX]

I run points in my 383 every day car. But as I remember it being described in a Mopar book about the electrical system… a breaker points ignition is in a constant state of going out of tune because of the wear to the rubbing block. And unless you get NOS they are all made in China. My experience with Chinese replacement parts is a crap shoot sometimes. The nice thing about electronic is the hotter spark, and maintenance free operation. Personally, I think the HEI one wire setups are the easiest to install.

 

[Geoff 2]

^^^^^^ Yup. You have hit ALL the nails on the head....

 

[Sinitro]

Sinitro,

We could debate until the end of time about different igns & their reliabilty. I have seen people using dielectric grease under the HEI module......it fails....& then they blame the module!
I have TWO Chrys ECU boxes here where the sealing 'goo' in the back has become almost liquid & run out.

The major failure issue for the GM type HEI module is due to inadequate heat sink surface area.
As the ignition system is pushed hard the module heats up and its main device has secondary breakdown.
The device shorts out and one is stuck in the middle of nowhere, we have done some installs using the GM module
by mounting it externally remotely on a dedicated heat sink. With the additional heat sink area the module should survive as long as it is
not one of the cheaper off-shore pieces. My personal experience and endurance with the legacy Mopar OE iginition modules
is they are literally bullet-proof as back then Chrysler had hefty QA standards. Also after installing multiple electronic ignition systems for multiple auto publications
and being called upon by local car guys in many use cases ECU module and/or coil failure is often due to to intermixing various brands of ignition components.

Just my $0.02...

 

[Geoff 2]

Totally agree about failures due to component mixing, especially using ign coils with the incorrect primary resistance, failure to use a bal res when needed or wrong bal res.

Totally disagree with the heat sinking comments. Over the last 20 years, I have rebuilt many GM engines that had HEI ign located at the rear of the engine. They really get 'cooked' back there, the ultimate heat test. Many of these engines had original HEI dists & were still working fine after 35+ yrs of use.

The Chrys ECUs do fail. My friend would have problems where the ECU overheated on long trips; he would have to pull over & let things cool down. ECU was mounted on the inner fender to keep it as cool as possible.

 

[OneWheelPeel]

For what its worth I believe the HEI in my 77 Vette is original and it gets cooked and it still going. I also just jinxed myself.

 

[Sinitro]

Totally agree about failures due to component mixing, especially using ign coils with the incorrect primary resistance, failure to use a bal res when needed or wrong bal res.

Totally disagree with the heat sinking comments. Over the last 20 years, I have rebuilt many GM engines that had HEI ign located at the rear of the engine. They really get 'cooked' back there, the ultimate heat test. Many of these engines had original HEI dists & were still working fine after 35+ yrs of use.

The Chrys ECUs do fail. My friend would have problems where the ECU overheated on long trips; he would have to pull over & let things cool down. ECU was mounted on the inner fender to keep it as cool as possible.

The majority of ignition modules and component failures are due to heat buildup and overheating...
Google the Corvette and Mustang forums, they are loaded with mention of ignition module failures.
Note that any brand ignition component can fail over time but my personal opinion and experience
with legacy Chrysler mechanical and electrical components they were designed and built to the highest QA standards.
However todays' automotive components are sourced and built by the cheapest factory and thus have poor reliability and shorter life.

Just my $0.02..

 

[Sinitro]

Sinitro,

We could debate until the end of time about different igns & their reliabilty. I have seen people using dielectric grease under the HEI module......it fails....& then they blame the module!
I have TWO Chrys ECU boxes here where the sealing 'goo' in the back has become almost liquid & run out.

If the module is leaking sealant, that tends to indicate it was subject to overheating. It's been my experience too many guys mount the Mopar ignition module on the firewall, which really gets hot with all the hot air coming off the engine. My preference is to mount the ignition module down on the frame rail just below a front mounted distributor, this location is cooler than the firewall and actually has a slight breeze airflow when the car is moving.

Just my $0.02...