Comparison of electronic ignition MMI vs Indigo

[joe_db]

I haven't had a coil burn out in many years, but the ballast resistor issue with the EIs was not known way back then.

[ndutton]

OK, cool. That fits into the time line of this forum's electronic ignition experience. I remember my very first post on the forum way back in 2009. It asked the question, "If electronic ignition is so great, why does everybody carry their old points plate to swap out after the engine dies as a get-home measure? It seems every post I read on the advantages of electronic ignition includes a failure episode. What's so great about THAT?"

It's interesting about the ballast resistor strategy not being known. We had the anecdotal information right here on the forum but it was spread out all over the place. All that had to be done was gather the info, develop a hypothesis and test it. The end result was a previously vexing problem was solved and we have enjoyed reliable operation since. I think we can all agree the issue was solved so this vari-dwell tech is a different way, albeit the most expensive to date, to skin the cat, a cat that has already been skinned.

[Wrsteinesq]

An old friend and mentor, now long dead, was in Scotland in the years following WWII. He saw old stone buildings being fitted with plumbing for the first time. The pipes were being installed outside the buildings. He thought that was odd for a climate that froze, and he asked why the pipes were being fitted outside the building. The answer he received was, “If you dinna place them outside, how can you get at them to pour boiling water on them when they freeze?”

If placed inside, those Scottish pipes might not freeze in the first place, requiring the boiling water. (Yes, I discount the difficulties of refitting stone buildings, but the point remains.)

I see this issue in a similar light. It may work, and even work fairly well, but it has never seemed to me, even as a non-engineer, that adding resistors to curtail excessive current was as good a solution as not sending excessive current in the first place. I’m not sure how excessive current or hotter-than-necessary coils is a good thing. My layman’s understanding of good engineering practice is to provide that which is necessary to do the job; and anything beyond that is wasteful.

This isn’t intended as a rant. No one, at least that I know of, is saying that this solution is a panacea. No one is saying that everyone needs, or even wants, this solution—and clearly, some don’t, and that’s just fine.

More importantly, not everyone accepts that before a potential improvement can be offered, that it must somehow solve a documented problem, whatever that means. Maybe there is no documented problem, but what is being suggested is or at least appears to be an improvement, anyway. What’s wrong with that?

If this turns out to be a good thing for our motors, I hope our host offers something similar for the Pertronix units. I don’t think this is new technology, just a new application. I hope this forum remains an open discussion for whatever might be good for our motors, whatever the source.

[ndutton]

Points taken Warren and expressed eloquently. As for checking excessive current in the first place, current is only one factor in a triad relationship, voltage and resistance being the other two. Alter any factor and the others fall into balance in the system.

One of my big concerns as the discussion has progressed has been bang for the buck, $100~$200 for a new vari-dwell system or $8 for a resistor if it's even needed, $0 if it's not.

edit: Question for you Joe - when did you make the move to a three stage "smart" regulator?

[joe_db]

I don't have a 3 stage regulator. I got a heavy duty adjustable regulator ages ago that appears to be totally indestructible. We used to get them packed in with Powerline alternators and none of our customers wanted them.
My battery charger OTOH is quite smart with temperature sensing and does vastly better than it's semi-sentient predecessor.
Back to ignition - we are slowly working up the food chain from 1920s tech. The electronic breakers point is early 70s tech and the variable dwell is probably early 80s. Next up is capacitive discharge where the coil is not storing energy at all and gets fired from a capacitor bank like a camera flash. To catch up to modern cars we need to ditch the distributor entirely and do coil-on-plug

[ndutton]

What output voltage is your regulator adjusted to? You've had this reg a long time?

[joe_db]

What output voltage is your regulator adjusted to? You've had this reg a long time?

I have had it since about 1994 or so. I think I have it at 14.2 or maybe 14.3, but now it is warmer it will be turned down to 14.1 volts until next winter.

[ndutton]

Well, good luck with the CDI project.

[toddster]

OK, cool. That fits into the time line of this forum's electronic ignition experience. I remember my very first post on the forum way back in 2009. It asked the question, "If electronic ignition is so great, why does everybody carry their old points plate to swap out after the engine dies as a get-home measure? It seems every post I read on the advantages of electronic ignition includes a failure episode. What's so great about THAT?"

I still haven’t made the leap to EI, but... I’ve had plenty of failed optical choppers and failed Hall effect sensors. Can’t decide which I trust least. I see that both teams do offer spare sensors, which would be an alternative to carrying the points. But... what’s the failure rate for these particular units?

[ndutton]

My Pertronix EI has performed flawlessly for 9 years. The same cannot be said for the HotSpark system I tried on a spare engine, it failed after very little use. Also, I cannot recall a single failure report (Pertronix) on this forum that did not involve owner abuse such as ignition left on with the engine not running or excessive system current.

[joe_db]

Some Google-Fu shows people complaining about pretty much every single aftermarket EI system ever made failing at one point or another.
This is one of my inspirations for my long delayed dual ignition idea. It keeps getting put back because the points are doing just fine for now. This is one of my "this tech is really cool what can I make it do" vs. "if it ain't broke, don't fix it" deals.

* the history seems to go device X was great, production moved to China, and now device X is not as reliable as it was back in the day.
** note the failure mode is different. Points tend to get worse and worse with starting getting harder and harder. If the IE module dies, it is not usually going to gradually get worse. It is alive 100% one second and 100% dead the next

[ndutton]

I'd be interested in the details of the reported failures considering our experiences on this forum. That is, we had failures too, a lot of them. Then we didn't.

[joe_db]

I'd be interested in the details of the reported failures considering our experiences on this forum. That is, we had failures too, a lot of them. Then we didn't.

I had one XR700 module fail. It had led a hard life in the pre ballast resistor days. I have not heard of any since the resistors came out, YMMV. I also had my Evinrude outboard EI fail. I was coming up to the dock and it just stopped.