Petronoix III. What's the Good, Bad and Ugly of these things?

Not sure what petronix (1, 2 or ??) I had but had one in the dizzy on the 440 in the wagon and it was a dog, couldn't figure out how a 440 with a 3.23 suregrip couldn't even get the rear tires to break loose even in the rain!! Finally decided one day to convert to the OEM mopar electronic ignition system and the motor was night and day different...it would pop those tires loose with just a light tap of the throttle, so guess I had a faulty petronix system.
 
Wildaugust said:
Does this apply to Pertronix as well, or only to the Chrysler electronic ignition systems? Can Pertronix work and survive with the mechanical VR?

I'm not going to be installing a Pertronix, because I've already converted to Chrysler electronic. I'm asking this for anyone thinking about going with Pertronix.

I hear quite a few complaints about Petronix units failing and wonder if running them with mechanical VRs could be one reason. Another issue with some older cars is not having an ACC position on the ignition switch. So, when people are parked listening to their radio/stereo they have the key in the ON position, which is not a good idea with any ignition system.
Click to expand...

Change out the mechanical regulator for any electronic ignition. The mechanical units produce static from the points opening and closing and electronics hate static. That was why Mopar changed the alternators and regulators for the '70 model year. And yes, a lot of aftermarket electronic ignition failures are caused by not upgrading the regulator as part of the conversion.

Dave
 
Wildaugust said:
I hear quite a few complaints about Petronix units failing and wonder if running them with mechanical VRs could be one reason. Another issue with some older cars is not having an ACC position on the ignition switch. So, when people are parked listening to their radio/stereo they have the key in the ON position, which is not a good idea with any ignition system.
Click to expand...

That was an issue with the Ignitor I and I should have mentioned that when I suggested the Ignitor II.

Yea, not a great idea to leave the ignition on anyway, but the Ignitor I was prone to fail, depending on where it was in the ignition sequence. From what I've read, the II has a protection circuit to prevent this.
 
thrashingcows said:
Not sure what petronix (1, 2 or ??) I had but had one in the dizzy on the 440 in the wagon and it was a dog, couldn't figure out how a 440 with a 3.23 suregrip couldn't even get the rear tires to break loose even in the rain!! Finally decided one day to convert to the OEM mopar electronic ignition system and the motor was night and day different...it would pop those tires loose with just a light tap of the throttle, so guess I had a faulty petronix system.
Click to expand...

You could have gotten a bad unit. More commonly several things cause poor performance with this unit: Pertonix bolts into the stock distributor, if the advance curve is not set up properly, the engine will run like crap. Might also have had a bad vacuum advance. Pertronix also does not like a factory tach if the vehicle was so equipped. The third thing that happens is the Pertronix needs 12v to operate so if a ballast resistor was left in the wiring, the unit will perform poorly if it runs at all.

Dave
 
That's another reason I liked the Pertronix and considered it. Bridging the ballast and everything under the stock distributor it looks absolutely factory. They make a coil that is black also so no one would know.
 
Yeah, I agree. I like stuff that still looks factory, but is far from it. I'm looking at the Ignitor II series for dual points. Think I'm going to jump in and change it out. Along with recently changing from a mechanical to electronic VR, this will be a nice mod.
 
I never understood the real value of dual points. It must have worked I guess. As I understand it it is basically two distributors in one doing the same thing each points set has 8 cam lobes. I always wondered why not have each set fire half the engine or 4 cylinders or 4 cam lobes each with their own coils that way the dwell would be increased by at least 50%. I have heard of such a system I believe that did this. Seems to me redundancy of standard dual points ,,if one cant fire hopefully the other will scenario . Interestingly it was used for high rpm applications ,,maybe I am wrong but still ,,
 
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Turboomni said:
I never understood the real value of dual points. It must have worked I guess. As I understand it it is basically two distributors doing the same thing each point set has 8 cam lobes. I always wondered why not have each set fire half the engine or 4 cylinders or 4 cam lobes each with their own coils that way the dwell would be increased by at least 50%. I have heard of such a system I believe that did this. Seems to me redundancy of standard dual points ,,if one cant fire hopefully the other will. Interestingly it was used for high rpm applications ,,maybe I am wrong but still ,,
Click to expand...
The dual point distributor has extended dwell time. One set of points closes and the other set opens the circuit. The two sets are offset from each other several degrees. So the time closed is increased by that difference, thus increasing the dwell angle. When the dwell is increased, the coil has longer time at saturation. This is important at high RPM so the coil has sufficient time to reach full saturation.

I looked for a video that explained that, because a picture is worth a thousand words... I found this... It starts with explaining coil saturation time and at about 1:30 the dual point explanation starts and it ends about 3:30. Honestly, I stopped at about 4:00... I'm tired.

 
The dual points allowed for a longer dwell time, for a potentially higher coil output to the spark plugs. A longer dwell that was not possible with a single set of points, at the same point gap. A "high performance" upgrade, back then.

CBODY67
 
When I started considering the Pertronix system, when the "I" was all there was, it seemed to be favored by those on the Buick forum I was on. The "II" came later, which was supposed to be a better system, but there were comments about failures with that system, in earlier times. The III came later, which I believe has multi-strike capabilities, but at all rpm rather than just up to 3000rpm as MSD did.

I used to believe that the Chrysler electronic ignition kit, with an MSD control box, would be a good upgrade from points. Which a Pertronix III might provide, too?

Just some thoughts,
CBODY67
 
CBODY67 said:
When I started considering the Pertronix system, when the "I" was all there was, it seemed to be favored by those on the Buick forum I was on. The "II" came later, which was supposed to be a better system, but there were comments about failures with that system, in earlier times. The III came later, which I believe has multi-strike capabilities, but at all rpm rather than just up to 3000rpm as MSD did.

I used to believe that the Chrysler electronic ignition kit, with an MSD control box, would be a good upgrade from points. Which a Pertronix III might provide, too?

Just some thoughts,
CBODY67
Click to expand...
I've run the MSD in three vehicles now. First was the Roadrunner I raced back in the seventies. I really liked it... It performed well and had the advantage of not having to use "warm up" spark plugs. You could drive the car out of the garage, on the trailer, off the trailer, warm it up etc. and not need to change the plugs to go racing.

The second car was my A12 Roadrunner. It had the dual point and that was just fine, but for a while, that car got moved around a lot (long story). It would be started, moved 30 feet, and then moved back. This happened about 20- 30 times for each time it was driven... Even though I had the car jetted right, the plugs would get fouled after a weeks worth of screwing around with this. I added a MSD and it solved the problem. The car started right up and ran great (had a lumpy cam). It was the best ignition period.

I also ran one in a Jeep Grand Wagoneer. It worked great in that and the only reason I used it was I had bought a used one for another project that I never used and when the ignition box went in the Jeep, the MSD was sitting on the shelf. It started every time, but it was overkill for this vehicle.

The multi strike has less "strikes" as the RPM goes up. I don't think the Pertronix III is any better in this over the MSD.
 
Not that it might matter, but the original MSD company we had back then has been sold many times since back then. They discontinued the basic stock replacement box with the Chrysler plug-in on it (which is the one I have on my '67 Newport). The ones above it were more race-oriented, back then. Overkill for my applications.

Thanks,
CBODY67
 
So what's the best version of this unit? Seems like the Ignitor II to me. The III looks like it really made for a more Hi-Po situation, I won't need that. The II removes the Ballast and looks like it has the best options with automatic timing adjustments.
 
James Romano said:
So what's the best version of this unit? Seems like the Ignitor II to me. The III looks like it really made for a more Hi-Po situation, I won't need that. The II removes the Ballast and looks like it has the best options with automatic timing adjustments.
Click to expand...
I think the II version is.
 
I’ve had probably 25k cumulative trouble free miles with version I.
 
Big_John said:
You guys are mixing up current and voltage again, but I digress.
Click to expand...

Well the fact remains Big John that 1960's vintage points ignitions ran 6 volt coils not 12 volt. And is why they worked well in stock cars for many years on 12 volt cars and the reason for the ballast. 12 volt coils Do not work well on points ignition with a ballast resistor as I assumed.
They [6 volt coils] were a carry over from 6 volt ignitions of the 50's and before and the ballast kept them alive on 12 volts in the 1960's when 12 volts were then norm..
I guess 0n 12 volts the points would burn up yes??,,,,Yes,,of course they would.
 
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I just hate to see anyone having a problem with a points ignition and then putting down the whole system because of a misinformed parts application.
It can work really great!! That is why I am going to use points on my stroker and I refuse to even consider any GM thingy under my hood..
 
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