The Jalopy Journal
Discussion in 'The Hokey Ass Message Board' started by chucksrodgarage, Sep 8, 2013.
Have had several Pertronix coils go bad
why not use the MOPAR electronic ign that was OEM on later /6's. Plug and play with the correct donor car, assuming you have changed to 12V neg. Several folks have converted those systems and modified distributors to fire their flathead 6's once they went to 12V.
points triggering an MSD. You'll probably never replace the points in your lifetime...
You say it has a slant 6 in it if so use the stock mopar electronic dist in it and quit messing around with the aftermarket junk. It is a simple conversion.
Ignition modules die from heat. They use the distributor mounting plate as a heat sink. Look at the size of the contact surface of an HEI module compared to the ignitor II. The HEI module is mounted to the aluminum housing and uses it as a heat sink with thermal conducting grease.
With the Pertronix you have a smaller area going to a steel breaker plate. The contact between these two surfaces will be critical. They must be clean, then coated with the thermal conducting grease. Use a scotchbrite or similar to polish the two surfaces, drop by an electronics store and get a good quality thermal grease for a CPU Not much better but better, easier to apply with the Syringe).
The Ignitor II is rated for a .6 ohm coil. I would add a .25 Ohm ballast resistor to drop the current if I had a low ohm coil and experienced repeated failure. Place it next to the coil, the module wants 12 volts.
The despiking diodes are a good idea, the AC clutch is a big offender. When we would lose one (they are in the connector) we got all kids of issues.
Rarely do we need a super hot ignition on a relatively stock engine. A little moderation on coil current can greatly extend component life. For your 6 I would want closer to 1.5 ohms total (coil plus ballast).
With a breaker point ignition we are maxed out at 4 amps, and HEI was 5.5 and needed a large heat sink to survive.
Of course metal wires would be a no-no.
I almost agree: Run the Mopar electronic dizzy, but with a basic GM 4-pin HEI module. Best of both worlds. Cheap & simple.
Much discussion & explaination of it at Slantsix.org:
we have had good luck with pertronix ing. but. you can not run solid core plug wire. they will kill pertronix modules.
And probably solid spark plugs as well.
I try to use factory stuff whenever possible. They are made to last the warranty. Aftermarket stuff is made to get out the door of the store.
And if you want parts? Factory is easy. Aftermarket, forget it. Buy an entire new one buddy.
This guy has some stuff on factory electronic ignition;
Ya the factory went to electronic just so they could sell more stuff.
just got this email from one of the head people at pertronix. he also attatched a link on testing power and ground.
no i am running taylor spiral core wires, all testing at 2000 ohms or greater
I am not sure exactly what steps our tech department recommended. I would guess that they went through the whole resistance wire thing, They hopefully verified that your system is 12V, and they probably hammered you about power and grounds. If not, please do go through the steps in the attached PWRGND document, because bad power and ground circuits account for 90% of our customers problems with Ignitor modules. Sometimes they are not obvious problems.
The tech department may also have asked you whether you are running solid core plug wires. My best guess is that your issue has something to do with this. Ignitor II modules will not last long at all running in the presence of solid core plug or coil wires. You can check them by removing a plug wire and placing the leads of an Ohm meter on each end. There should be at least 500 Ohms of resistance across the wire if it is not solid core. Dont worry if there is a lot more resistance, the spark energy has no problem getting through the suppression wires, it is only the noise that gets blocked.
Please do that check, (dont forget to check the coil wire too) and if you still have a problem, you can send the module to me directly (mail it in with ATTENTION: Patrick on the label). I will dissect the module and see if I can figure out why it failed.
this is the link he sent. don't know if it copied correctly though.
PWRGNDCHK10JUL 029.docView online
tried link again
last one should work
Nope, it's asking for a name and password to view it.
Do you happen to have a schematic on how to wire?
With a Chiltons manual that has a Chrysler electronic ignition wiring diagram its not hard to wire up the OEM equipment that can be bought at all the parts stores,done it on a 68 Newport years ago and use the OEM electronic ignitions on all the cars I convert.
Be sure to heat sink the GM Module if you go that way.
My pertronix is 7 yrs old on my 390 fe ford.Just sayin!
I've used pertronix in everything I've built. Fords, Chevys, Buicks, Packards... never had one fail. I have one that is going on 17 years old!
I have seen a couple coils fail (not mine) due to heat and being left on.
I too have a Pertronix kit and coil in a SBC since 2001 with no problem.
...I fail to understand why anyone would use pertronix in a Mopar when the factory electronic system and replacement parts are readily available everywhere ....
Personally, I would stay with a points and condenser ignition. Easy to fix in the middle of nowhere and they have worked well for many years.
Good call, George. I've been using this setup since the early '70s. Works great. Not really traditional but the box is hidden behind the dash. Nobody should be looking under there anyway.
found some at the following places : ( to get anybody out of a jam)
for ours or oem modules.
Your belief would be fully wrong. Out failure rate is well below the industry standards and more importantly the PerTronix Modules are made in San Dimas California, so please do not try and start rumors about our electronioc products being Chinese
Really, although I like the MSD/points deal, I agree with this. Nothing at all wrong with the factory Chrysler stuff for this application.
I have never run a Petronix ign in anything of my own but from dealing with electronic ignition problems on a number of other setups I'd have to say that any rig having multiple ignition system failures on the same component has some additional problem added in to the mix.
As others said, voltage spike, high voltage, wrong grounds or other incorrect installation. Add in something in the secondary circuit that is causing too high of a resistance and who knows what else in the mix.
I use a PerTronix as well. I have the Pertronix II and I believe they recommend that you use the Pertronix II Coil (which I believe is the high output flamethrower coil) as they are designed to run together. Hotroddon would know for sure. Make sure the coil you are using is compatible with the Pertronix unit in your distributor.
Also, as was stated and I'm sure you know, I never leave my key in the 'on' (or 'Power') position for ANY length of time as it will fry the PerTronix unit.
Been running a pertronix II in my rocket for about 4 years now and runs great. And with a 32A generator.
I blew my first pertronix (I) because I used the wrong coil with it. I then talked to pertronix about it and then went with a pertronix II with one of there coils this way I had a complete matching system. Been running ever since.
The other thing I did was remove my dizzy when I installed the module so I could properly space the module and insure proper spacing over the entire dizzy rotation.
As someone said above you may have some underlying issues if you keep blowing these units.
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