Happy new slant year, y'all,

Dan's last HEI post has begun my move to HEI from my Pertronix which works perfect, but since I always like to be piddling....

I have thought and sketched the flow in my charging circuit but can't reason how the HEI system would, or might not, interact with what I now use. I use an internally regulated GM alternator and took the firewall voltage regulator out of the circuit. Ammeter was removed and replaced with a volts meter, and as I said using Pertronix and all works perfectly.

But if I swap to HEI is the internally regulated alternator still usable in the circuit, or put another way, are HEI and an internally regulated alternator compatible?


Oh and if I am poking around, do you all use dielctric grease on your plug to wire connections?

Thanks
rock
'64d100

Thanks for that question Rock. I am looking forward to Dan's response. I would think they are completely compatible since that is the standard alternator GM uses now. Did you put any resistance in the voltage reference line to your alternator? I have been told that GM ran this circuit through the dash charge light to put some resistance in the line. In some cases they ran it through the electric choke pull off. I was told, and don;t know if this is true, that full feed back to the alternator without some load is hard on the transistors, or diods or some such internal component. I put a standard relay coil in my line. It just sits there doing nothing but adding resistance to the alternator circuit. Maybe there is some circuit I could turn on with this.

Dan, whatch know about this?

Sam

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The hei don't care what alternator you are running, as long as it gets power...

Rust Collector is right. The ignition system cares very little about the charging system provided there is enough voltage and current is available. The voltage regulation is completely independent of the ignition system.

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Joshua

Here's another vote for Rust Collector's assertion. The ignition wants to see a stable, well-regulated voltage, as free as possible of transient spikes, ripple and noise. How that is achieved is of no concern to the ignition.

I would definitely vote against any resistance in the voltage sense line to the alternator/regulator. It sounds like this idea arose out of a misunderstanding of how the GM circuit was originally set up. Sam, this means I would be inclined to remove the relay coil you mention, which I assume is in series with the voltage sense line. If one were concerned about avoiding spikes on the voltage sense line, then a thoughtfully-selected capacitor would provide ample protection without causing other problems. The effect of resistance in the sense wire is to increase line voltage. It's one way to artificially increase the effective setpoint of the regulator, I guess, but not one I would be entirely comfortable with.

On the other hand, if you are trying to reduce engine cranking load by taking all electrical load off the alternator during cranking, then a NC relay's contacts can be put in the appropriate wire to the regulator/alternator such that during cranking, the alternator is "turned off" , has no electrical load, therefore imposes no mechanical load on the engine.

But most of us don't have problems with excessive alternator load interfering with engine startup.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Sam, Dan, Rust Collector and Joshie,

Thanks guys! I have resisted ( don't mind the pun) going to HEI ONLY because I had not yet benefited from Dan's dissertation about it before I encountered the Pertronix. WHile mine Pertronix works PERFECTLY, I am aware of the reports of the occasional unwarned failure of same. Since I am basically done with my engine work I have been inching towards what logic tells me is anignition approach less known for unwarned failures. I originally went with the GM alternator because I knew how to replace diodes in them if a problem occurs, they are easy to work on, and easy to re clock when I moved alternator low on driver side to shorten total belt length. I also moved my coil to firewall and was trying to get only plug wires, distributor and oil filter on the plug side of block. Works fine, easy to do adjustments on as a result.

What Dan, R.C. and Joshie say makes the argument "for" that I had kinda thought through, but my recent carb. experience makes me doubly determined to run odd stuff through this board's wisdom. What I had mentally sketched out as 'against" was not knowing if HEI stuff induced (as in real induction per the coil load and discharge) a spike. I didn't see why it would, but knew others would know for sure.

So Sam, all my GM friends and literature agree with you that the there was a resistance put in place with the light. When I first began my total rewiring project I was determined to create the shortest possible primary circuit and "clean up" all secondary circuit elements by installing relays for every high amp function....high and lo beam, horn, wiper, heater, etc. I used a fusible link for each relay and also fused each of the sub circuits for double protection. I ran a 6 gage ground line under the dash so my new gage lights all had a good ground, and also ran a separate 4 gage hot line onto which which taps could be soldered if I wanted to add something like a radio or what ever.

It took a long time to do it right, color code it and draw it out, and add in dual oil gage and lights, dual charging light and volts gage, etc. but the results are worth it. You cannot believe how bright standard filament bulb headlamps can be when well supplied, and putting an oscilloscope on my alternator output shows a beautiful clean waveform. I did all this in case one day I go to EFI, because after seeing Dart270's EFI, I planned for a clean waveform in case I go EFI.

All my wires are on the fenders, none drape over the block, thus making tuning easy and head pulling and valve adjustments easier.. My VOM shows a steady 14 volts output and my battery sits at 13.2. Very satisfying. It appeared to me that GM missed what Mopar didn't...Mopar using the starter relay and GM not, created a high draw circuit that was much too long. The beauty of having a #4 wire from relay to starter hot that is only 21 inches long is that my engine starts running before you even hear the starter turn. Of course it does turn but not even 90 degrees before running, much easier on all starting components and eerily similar to a 110vac motor when you put it's plug in a wall.

Sorry to digress...I didn't want to mess up a great electric system unknowingly and you all seem to be confirming that HEI is cool with an internally regulated system....just what I wanted to know and so THANK YOU!!
rock
'64d100

Actually, a relay coil might be a great choice because its an inductor, which will smooth out ripple and spikes on a voltage-sense line much better than a capacitor alone would. The only thing is that a relay coil *might* have too large of a resistance value, so a noise-suppression inductor intended for the power supply line to a car stereo might be a better pick. But frankly, I'm guessing that only a few milliamps flow through that sense line, so it would take a really large resistance (several tens if not hundreds of ohms) to skew the voltage setpoint.

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That's an interesting idea, using a relay coil as an inductor. I hadn't really thought of it that way. But I would be concerned with exactly what you mention: the possibility of excessive resistance = excessive voltage drop in the sense wire, screwing up the line voltage. I don't know how much current runs through the sense wire. Perhaps you're right that the resistance wouldn't be a concern.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

On older alternators / regulators where the one wire to the regulator is a sense wire and power source that the goes to the field wire (going out of the regulator) there is the possibility of a couple of amps going thru that wire. Any resistance would mess up your voltage regulation.

Not sure what happens where the field wire doesn't ground out in later alternators / regulators.......... (or how many wire in the later regulators)

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Dielectric - "A non-conductor of electricity, esp. a substance with conductivity less than a millionth of a mho".

Put the grease where you don't want the spark to go, the way I see it. Like on the plug wire boot or plug ceramic. It may also help as a moisture barrier or electrolysis preventer, I'm not sure.

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'63 Valiant V200 Convertible
225 Aluminum Block