Ford Muscle Cars Tech Forum banner

61 - 80 of 88 Posts

·
Registered
Joined
·
10,305 Posts
BTW - I didn't compare the systems to the PerTronix versions. So, although I don't have access to corporate secrets and schematics, nor have I used an oscilloscope to prove each one, I would say that based on their characteristics:

  • The P-I is fixed dwell without current limiting (like points) and therefore uses a coil resistor.
  • The P-II appears to use fixed dwell with current-limiting like the GM 4-pin, and therefore no coil resistor.
  • The P-III appears to use calculating power for true dwell control, and uses some of that calculating power to also incorporate multi-spark, and determine RPM for rev-limiting. It therefore uses no coil resistor. However, due to it's ability to somewhat adapt to other coils than the one recommended, I believe it also uses current-limiting. Or, it's a lot smarter than we give it credit for.
I don't tinker with distributors much anymore, and most of the stuff I play with is distributorless with multiple coils and full dwell control. However, if working on a distributor car that's stock or mild, and power or hair-splitting economy were not required, I'd probably just use a P-I or similar conversion. It just has to run. Much wilder than that, I'd probably go straight to the P-III or equivalent and lots of sharp tuning for all the benefits of the whole enchilada.


David
 

·
Subscriber
Joined
·
650 Posts
Think of the coil like a bucket, and the water flowing into it is from a faucet.
Dang, PSIG. That is GOOD.

I've been reading up on ignitions for years, and this is the best Pertronix thread i've ever seen. Seriously- this should be a sticky.
 

·
Registered
Joined
·
408 Posts
I agree and think it should go in a different area of the site. Maybe re-title "before you install a Pertronix read this" or something to that effect cause there may be other people in other areas of this site that don't follow the Galaxie pages and have installed it incorrectly due to just following the instructions.
 

·
Premium Member
Joined
·
34,853 Posts
BTW - I didn't compare the systems to the PerTronix versions. So, although I don't have access to corporate secrets and schematics, nor have I used an oscilloscope to prove each one, I would say that based on their characteristics:

  • The P-I is fixed dwell without current limiting (like points) and therefore uses a coil resistor.
  • The P-II appears to use fixed dwell with current-limiting like the GM 4-pin, and therefore no coil resistor.
  • The P-III appears to use calculating power for true dwell control, and uses some of that calculating power to also incorporate multi-spark, and determine RPM for rev-limiting. It therefore uses no coil resistor. However, due to it's ability to somewhat adapt to other coils than the one recommended, I believe it also uses current-limiting. Or, it's a lot smarter than we give it credit for.
I don't tinker with distributors much anymore, and most of the stuff I play with is distributorless with multiple coils and full dwell control. However, if working on a distributor car that's stock or mild, and power or hair-splitting economy were not required, I'd probably just use a P-I or similar conversion. It just has to run. Much wilder than that, I'd probably go straight to the P-III or equivalent and lots of sharp tuning for all the benefits of the whole enchilada.


David

That's what I'm talking about Pert I no control just a steady dwell.

Pert II I'd like to know the secret but your Explanation like the GM module makes sense although I've not seen one in person.

I knew all about the bucket of water analogy, it's the DWELL control that I didn't believe, and still can't fully accept without a deeper look at the electronics of a Pert II system.

I don't use the II or III system because I don't race...
 

·
Registered
Joined
·
10,305 Posts
Actually, dwell control is a fairly simple process, and a child's digital watch has the power to do the calculations, though it may not have the speed at $9.99. Let's break-down the process:
  • Coil ON time
  • Firing time
  • Wait time
We have had electronic tachometers for 50 years, and it's simple to calculate. The module sees the RPM, and therefore knows how long it has at the current RPM to accomplish the 3 steps above. Using a V8 at 1000 RPM, time between firings is .015 seconds or 15 milliseconds (15ms). Let's say your coil needs 4ms to fully saturate, and it takes 1ms for the spark to fully fire (spark burn). So:
  • Coil ON = 4ms
  • Firing time = 1ms
  • Wait time = 10ms
So, the module just uses the stopwatch function of your kid's watch to wait 1ms + 10ms before turning power to the coil on for the next firing for 4ms. There's your 15ms. Bingo - perfectly controlled dwell.

Here's the rub. At 3000 RPM, there is just 5ms between firings, and just barely enough time to get full power out of the coil with no wait time. Any RPM above that will give a weaker spark. To get it to spark to redline, we close the spark plug gap to .035" so the weak spark can still fire at that RPM. It still runs, but the power is down slightly from the small .035 gap and weak remaining spark.

Because we have dwell control, we can remove the resistor from the coil power feed. Now the coil will saturate in 3ms, and we can get full spark to 4500 and a stronger one than we had at redline. We might be able to open the plug gap to .045".

Want more? Then we switch to a coil that will saturate even faster, like an HEI/TFI coil. Now we can get not only full spark power at redline, but we can open the gap still further to get a much larger spark for more efficient mixture ignition with more power and efficiency. With the hot spark and faster burn, we may even be able to reduce the WOT timing advance a bit, further increasing our power output. And the arms race goes on and on...

David
 

·
Registered
Joined
·
193 Posts
I just installed the pII and 45k coil .6 ohm. I called tech support and they say to put full voltage to the coil and module.

The pII has variable dwell I confirmed this with a meter at 1000 rpm dwell is 10 at 2500 rpm it goes up around 25. It will also shut down if the ignition switch sticks on. The pI won't do that I have that on my 64 Galaxie and works fine but I dint trust the mustangs ignition switch so I went with the PII.

This thing works great took out any miss my 70 Mach1 had runs smooth.
 

·
Registered
Joined
·
406 Posts
I think what everybody is saying is if you have a stock coil leave it alone. If you have an aftermarket coil change the wiring, (for pertronix I) is this correct??
 

·
Registered
Joined
·
70 Posts
I have really poured over all 68 previous responses to this very good thread about installing a Pertronix Ignitor and still am somewhat unsure of all possibilities, though certainly more knowledgeable than if I didn't read all of this.

I am looking to install a Pertronix Ignitor 1 (Model 1281), the first and most basic unit in my 66 LTD w/352 engine. I am also looking to upgrade to the coil to the Pertronix Flamethrower 1.5 ohm, the model 40011, what they recommend to use with the Pertronix 1 when you want to upgrade your coil. Since my coil is an original yellowish top coil, I think 54 years of service is good and time to replace it.

From all I have read above, since I am going to install the Per 1 and their Flamethrower 1.5 ohm oil coil, they both need 12V to run properly. (The Flamethower coil spec sheet even says to remove the resistor wire.

Then, for the Pertronix 1 module to work properly, it needs 12 Volts switched at all times. I was thinking, instead of all this splicing into the pink wire that I am reading about, which is really alot more work, can I just run a connector wire from the back of the ignition switch threaded post, which when switched on does create 12V through that post. I would run that wire through the firewall, and to the + side of the coil. Then the black from the Igniter 1 to the negative of the coil and the red from the Ignitor 1 to the + of the coil- which I have effectively made a 12V switched constant source via that post on the back of the ignition switch.

I guess then the old positive connector of the Red/Green coil wire would just sit there unused in the engine compartment?

Any flaw in setting it up in this manner?

(PS, I have 2 Mustangs that I have run Pert Igniter 1's in, and did not bypass the resistor in neither and they ran fine, but from all I have read on this subject, I want to see if hooking it up like this will maximize my work and be the way to go)
 

·
Subscriber
Joined
·
650 Posts
Again - go back and read the 3rd post.
The first-gen Pertronix requires that you keep the resistor. No 12v to the coil.
 

·
Registered
Joined
·
70 Posts
Thank you for replying cuthrell. You were really one of the main contributors to this several years back and glad to see your still out here. So let me then modify what I want to do, and tell me (and others that read this in the future) if this will work:

I will keep using the resistor wire to the coil that currently goes to my old stock coil, even though I am going to replace it with the Flamethrower coil that is recommended for the Pertronix 1 Igniter.

Now, the bigger question, that I posed above, and I did not see anyone address this years ago. Instead of splicing into the wire harness ahead of the resistor, can I simply run a wire from the post on the back of the ignition switch, which I believe is 12 V on the start and run position, right to the red wire of the Igniter 1 module? It would accomplish one main thing- keep the original wiring from being cut into and I believe it is an easier installation that way.

Essentially, I end up with the Per 1 red wire having zero contact with the + side of the coil and it would be connected to this 12V source wire that I run through the firewall from the back of the ignition switch post that I have mentioned. Or, is it for some reason not prudent to use the post on the back of the ignition switch for such an application to obtain the 12V switched source for the Igniter 1?

(and, as a side note, why does the spec sheet for the 40011 Flamethrower coil say to remove the resistor wire?)
 

·
Subscriber
Joined
·
650 Posts
Hello JD-

very interesting.
Best I can tell, the Pertronix instructions have changed. I went and looked at the 1281 instructions on their website, and sure enough...it says to unhook the resistor if you're running the 1.5-ohm coil on a 8-cylinder. I was also able to image-search and find the older versions of the instructions that say "do not remove the resistor".

I'm not going to argue against their own instructions. I guess (hope) the dwell circuitry has gotten better, and is now able to handle 12v.

If it were me - I think I'd buy the Ignitor II, switch to a low-ohm coil (0.6, etc), and open up my spark plug gap.

Good luck, and keep us posted-
 

·
Registered
Joined
·
70 Posts
I decided with my stock Autolite distributor and very modest performance expectations (in other words, my 352 is just cruising around town and the occasional car show, not all that much highway), to stick with the basics, the Pertronix 1 with the suggested Flamethower coil, the 1.5 ohm coil they sell to match up with the Per 1 unit. After speaking to Pertronix direct on the phone, I got the impression that running the Per 1 through the resistor wire may not be recommended, but could very well work. (and, in the 1281 box are the instructions that still say to not remove the resistor.)

Since I have run this exact unit with another 8 cyl Ford before, with a stock distributor, and had no issues at all, I am going to give this a shot, running the Pertronix 1 right off the resistor wire to the coil + terminal.

Thus far, 2 days into it, yes, the car is starting up easier and idling better. Running great actually, but it was running well on the points also. I am sure replacing the original 54 year old coil itself was a big part of the upgrade for better performance. I retimed it, checked the vaccuum and all seems pretty good, I have all dialled in where it is running smoothly.

I will absolutely report if I have any issues down the road with this. If I do, I know what I need to do, by pass that resistor wire. Time will tell.
 

·
Registered
Joined
·
38 Posts
I did the exact same thing as Stefan....Pertronix Ignitor and the 1.5 ohm Flamethrower coil. Everything I read said the Ignitor needs a full 12V and to bypass that pink resistor wire from the IGN switch. Rather than run a separate wire to the Ignitor red wire and keep the stock wire to the coil, I wanted to bypass the resistor altogether and run the wire directly to the coil so that got a full 12V, too. I had an MSD Blaster II (stock replacement at 0.7 ohm) in there briefly, and it got really hot after driving around town. After having run the wires already, I bought the Flamethrower and preferred to go that route. Runs like a top, starts very easily, and coil stayed cool after a lengthy cruise around town the other night.
 

·
Registered
Joined
·
70 Posts
Update to my installation of the Pertronix 1 (1281) and Flamethrower 1.5 ohm coil (40011).

After my installation, which I detailed above a few weeks ago, where I choose to NOT bypass the resistor pink wire, I have more results to report.

After the first event free, low speed drive, I thought "all is great- good choice to NOT do the pink wire bypass". Why was I so hesitant to NOT do the pink wire bypass? Simple fear and frustration and lack of extra effort. While all my research and call to Pertronix pointed to the information that the coil and Pertronix unit ran best on a steady 12 volts, which cannot be produced when the pink wire resistor is still connected, I used my past good experience with the pink wire in circuit with another Ford car to make my decision to NOT bypass that pink wire.

I took the car for a ride the next couple of days, and started to notice a very short, but obvious stumble in RPM at about 50 mph. I am talking like a half second stumble, but for me, that is enough of a problem to investigate. I did NOT have that issue when running points, and the only change I made was to add the Per 1 and Flamethrower coil, NOT bypassing the pink wire.

I even took the wife for a ride in the car a couple of times (she has logged enough miles in the car to know how it runs). Once she noticed the brief RPM issue blip, I knew that it was something that I was going to have to fix.

I know coming back here for advice, exactly what I would hear- "bypass the pink wire"

And, that is exactly what I did. My initial reluctance on bypassing the pink wire on my 66 LTD was 2 things. First, I could not find it under the dash, as hard as I looked. And, two- I could not see a logical and good spot to fish a wire through the firewall to the coil. I knew that I was not the only 1966 Ford LTD with a Pertronix with a bypass wire, so I knew these were both able to be done.

To solve issue #1, I decided to so something different. Instead of looking under the dash from the drivers side, I laid down in the passenger side foot well and there, on my back with a flashlight, was easily able to spot the bullet plug Red/green stripe wire plugged into the Pink wire. The green stripe on the wire was pretty faded, but the pink resistor wire was a dead give away that I had found what I was looking for. It was not buried in the wire harness like I feared, actually it was very open and quite visible. I just needed to look from a different angle. So, I unplugged it, easy enough, and knew step one was accomplished.

I then created my bypass wire. I used a black wire, to make it look less easy to spot in the engine bay, 12 gauge wire. I soldered a bullet plug male connector onto one end of the wire, because I wanted a simple and solid connection to the Red/green stripe female bullet plug off of the ignition switch. (and also a very easy way to reconnect everything in case I had to install the Pink bypass wire back again if the Pertronix failed and I was on the road stuck and reinstall the points, splicing into the wire when I had a bullet plug available made no sense to me). I tested my new bypass wire for continuity after I soldered the bullet plug to it, and I had a good result, so it was time to run the wire through the firewall.

Issue #2 running the wire through the firewall, I had to be creative. There really are not any "Easy and perfect positioned" holes to get around the harness plugs on the firewall with the stock wiring. But, on my LTD, it does have one thing that I am not sure that other 66 models have, the "Silent Flo" vent system. This system, which actuates through a switch that opens vents in the rear deck of the back window, is driven by vacuum off of the engine. It gets the vacuum from a hose off the engine, the size of a windshield wiper hose, which goes, luckily for me, through a small hole on the firewall, just to the passenger side of the engine.

So, that was the path I took. Since the rubber hose that runs that Silent Flo system is pliable and able to be squished down abit, I was able to fish the bypass wire through this very small hole and it actually comes out exactly where it can run against the wire harness along the firewall in the engine bay, and right down to the coil. It was about a total 7 foot run. I used a small flat head screwdriver to push the hose down, to create the void that I could fish the bypass wire through it. I had to be careful to not puncture the rubber vacuum hose, as that would create another issue for me, hence I used something not sharp, like the flat head screwdriver I mentioned.

I then unhooked the old coil wire, the Red/green with the plug that goes onto the positive of the coil and then put a wire connector onto the other bare end of my new bypass wire. Before I did the final hook up, I did a test with a multi meter, putting the ignition to the on position and I was indeed getting 12 volts, so I knew my run and wire was successful and not damaged during fishing it through the firewall hole.

I connected it up to the coil positive side, along with the red wire from the Pertronix unit. I started up the car, no issue. I now had a successful 12 volt source from the ignition switch to the coil and Pertronix 1 unit.

I took the car for a higher speed test ride, to see if I had any issues. No issues, at any speed.

So, I am now here to add my .02 cents- even though various instructions from Pertronix and their actual support staff say the unit WILL work with a resistor wire connected, I did have performance issues when I did not bypass the pink wire. Once I bypassed the pink resistor wire, my issue went away.

I could have lived with the slight hesitation I had with the engine with the pink wire connected, some would have. But, I am not in this hobby for "just runs ok". I am a fan of as close to perfect as I can make it. And, bypassing the pink resistor wire. on this particular car, was the answer to make it closer to perfect as I could be.

I always like to see a follow up when something changes when someone posts about an issue, so now you have my experience documented here.
 

·
Registered
Joined
·
38 Posts
This is a great follow-up post. I did almost the exact same bypass thing from my ignition switch (easy enough to remove back of the ignition switch for access to the terminals on there while it's still in the car). I will say, I'm not use to working on cars with SO much room and accessibility under the dash once you finagle yourself into position down there!! The reason I came right off of the switch was because I did read in a Mustang thread where a small fire started at his spliced bullet connector and it put the fear of God into me. No idea why he had a fire, and I'm sure a bullet connector has no problem handling the full 12V (it does so now when going into the pink resistor wire), but I chose to leave that entire stock setup in place.

It runs VERY well like this, with coil staying cool and no start up or hesitation issues at all.
 

·
Registered
Joined
·
292 Posts
Thanks for the followup - this will help people in the future.

On my car with the 1281 and stock coil, I also chose to bypass the pink wire but went a bit different route. I didn't want to mess with the stock wiring under the dash so I just bought a small 12V relay, the kind with the standard terminal numbers (85, 86, 87, etc.) and mounted it under the hood next to the stock voltage regulator. I ran a short pair of wires to/from the coil area. One was from the original wire going to the coil +; the other is from the relay back to the coil. The other 2 terminals on the relay went to ground and to the wire on the voltage regulator that is connected to the battery. So the relay is energized when the coil wire is hot, and returns 12V to the coil. This way it can all be put back easily. Even though the relay is rated for "12V" operation, it works fine being activated by the slightly lower voltage from the pink wire.

Pat
 

·
Registered
Joined
·
70 Posts
1964Fastback, thanks for the good feedback. Before I got over my fear of looking for the pink resistor wire, I did consider using this Pertronix product, the Power Relay, which basically does something similar to what you described. It allows you to use the original stock wiring, no bypass needed. However, I didnt like that I would have had to connect directly to my batter Positive terminal, the length and look of a wire run that long would have looked lousy to me.
 

Attachments

61 - 80 of 88 Posts
Top