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Pertronix 1 Wiring
Posted by: JimBrandberg ()
Date: May 15, 2015 01:10PM

The last few years, I've been wiring Pertronix 1 by removing the resistance wire in the harness and running 12 volts. I don't think I've had any issues.
I'm installing one in UV420 which has a resistor module instead of a resistance wire in the harness. Like a Spyder I guess.
In the Pertronix 1 instructions, it shows the Pertronix red wire to the 12V side of the resistor module and the coil to the 6V side of the resistance module. Is it desirable to run the coil at 6V rather than 12?
I'm using a stock type coil.
I suppose it would make it easier to swap the points plate back in in case of a failure.
Jim Brandberg
Isanti, MN
CorvairRepair.com

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Re: Pertronix 1 Wiring
Posted by: MattNall ()
Date: May 15, 2015 01:20PM

Stock coil YES!! [ internal resistance is too low ]

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Re: Pertronix 1 Wiring
Posted by: oldqmguy ()
Date: May 15, 2015 01:29PM

Matt is right!

When the Automotive Industry went to 12 Volts GM (and everybody else) had thousands (millions??) of "6 Volt Coils" in stock! Resisters were a heck of a lot cheaper than buying 12 Coils and tossing their 'stock' in the trash!!!

Dale

Dale E. Smiley CPBE
Life Member The Society of Broadcast Engineers
RETIRED Broadcast Engineer
CERTIFIED CORVAIR NUT
CORSA/Circle City Corvairs/Corvair Performance Group
Avon, Indiana
WB9SFF
1967 4-Door Monza PG!

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Re: Pertronix 1 Wiring
Posted by: JimBrandberg ()
Date: May 16, 2015 06:25AM

Does a Pertronix 1 work well wired with the resistor removed for a full 12 volts along with a higher resistance coil like a Flamethrower? I was thinking that set-up was more for the Pertronix 2.
I have a Flamethrower chrome coil (not a Flamethrower 2). I suppose I should test the resistance.
Jim Brandberg
Isanti, MN
CorvairRepair.com

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Re: Pertronix 1 Wiring
Posted by: studevair ()
Date: May 16, 2015 07:02AM

I had pert 1 in my '63 and I have it in my '64 about 5,000 miles driven between the two as they are/were my daily drivers and the way I wired them both is to bypass the resistance wire and wire 12 volts to the ignition coil then just wire the pert 1 to the coil as intended.I use a NAPA IC14 coil which is made to use 12 volts I do not remove the resistance wire so that if I ever had to I can wire it back to the stock configuration with the points plate and original coil.It sounds like your application would be even easier as you can just pull 12 volts on the 12 volt side of your ballast resistor.

,
Patrick P.
Niagara Falls NY

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Re: Pertronix 1 Wiring
Posted by: Bob Helt ()
Date: May 16, 2015 07:30AM

JimBrandberg Wrote:
-------------------------------------------------------
> Does a Pertronix 1 work well wired with the
> resistor removed for a full 12 volts along with a
> higher resistance coil like a Flamethrower? I was
> thinking that set-up was more for the Pertronix 2.
>
> I have a Flamethrower chrome coil (not a
> Flamethrower 2). I suppose I should test the
> resistance.
> Jim Brandberg


Jim,
Pertronix sells two different FlameThrower coils for the Pert I. One coil has a primary resistance of about 1.5 ohms and is intended to be used with the Pert I and 12 v supplied to the Pert I but with the resistance wire or block in the circuit going to the coil. The other coil has a pri res of 3 ohms and can run with the resistance wire bypassed or out of the circuit. So you need to determine which of these two coils you have.

FYI, Pert II uses a coil with a pri res of only 0.6 ohms and shold not be used on a Pert I.
Bob Helt

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Re: Pertronix 1 Wiring
Posted by: 66vairman ()
Date: May 16, 2015 08:49AM

Bob Helt is correct. But there are a LOT of arguments about this.

After some work I finally figured out the issue. The Petronix Flamethrower coil table does NOT specify a coil for the Corvair. The table just calls out a six cylinder coil which is 3.0 ohm. The problem is the Corvair used a coil with about a 1.3 ohm impedance with a 1.8 ohm ballast resistance (total about 3.0 ohms). Corvair owners that used the Petronix Flamethrower (I) 3.0 ohm coil with the Corvair ballast resistor would call Petronix with complaints about poor performance and Petronix advised Corvair owners to remove the ballast resistor when using the Petronix Flamethrower (I) 3.0 ohm coil with a Pert I system. And the word spread.

If you use a stock coil then you must use the ballast resistor or the coil (and Pert I module) will conduct excessive current that will lead to a shortened life span.

BTW - When you use a 3.0 ohm coil and NO ballast resistor you loose the ballast by-pass function during starting and get a lower spark voltage than you would with a stock system. This makes cold weather starts more problematic.

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Re: Pertronix 1 Wiring
Posted by: JimBrandberg ()
Date: May 17, 2015 03:03AM

Thanks for the replies. I've printed off the information for reference.
Jim Brandberg
Isanti, MN
CorvairRepair.com

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Re: Pertronix 1 Wiring
Posted by: Bob Helt ()
Date: May 17, 2015 08:49AM

66vairman has nailed it. But let me go one step further. Pertronix is actually telling us to use the "wrong" coil with the Pert I by stating that the 3 ohm coil is for six cylinder engines. That may be true for other engines, but the Corvair should use the 8 cylinder coil, the 1.5 ohm one, if the ballast resistor is left in the circuit.
Bob Helt

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Re: Pertronix 1 Wiring
Posted by: gjordahl ()
Date: May 28, 2015 08:57AM

Sorry to dredge this up again. I thought I had an epiphany to my Corsa's low end stumbles this weekend, then I searched the forum to see if what I found is right, but now it seems if I implement what I thought was a fix I may burn up my Pert1.

I've had low end stumbling (idle-2500 rpm) issues on my Corsa 140 since I finished it 500 miles ago. By consensus I was pointed to low idle circuits in the primaries, but blowing them out, etc. seemed to only help a little and temporarily. The problem always seemed almost mechanical to me, like at 2500 rpm a switch went on.

This weekend I bypassed the resistor wire by running a wire from the battery to the coil. Boom! Problem solved! Like butta! So now I just need to bypass the resistor wire.

Then I looked at the coil I was using (MSD). It measures only .7 ohm primary resistance. Looked it up in the catalog and that is the spec. So, no resistor wire and a .7 ohm coil. Dangerous to the Pert module according to this forum?

I happened to have an old OE coil off a GTO, so I threw that in. It measured 1.5 ohm. With the resistor wire (1.8? + 1.5 = 3.3) it seems to work better than the MSD coil (1.8 + .7 = 2.5). So, if removing the resistor wire and using the MSD coil (0 + .7 = .7) seemed to work best (lowest resistance), why would the GM coil work better than the MSD with the resistor wire? Arrghhh!

Maybe my next experiment should be using the GM coil and no resistor wire, happy medium? Maybe the MSD coil is a bad match with pert1?

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Re: Pertronix 1 Wiring
Posted by: jzatarski ()
Date: May 28, 2015 11:35AM

gjordahl Wrote:
-------------------------------------------------------
> Sorry to dredge this up again. I thought I had an
> epiphany to my Corsa's low end stumbles this
> weekend, then I searched the forum to see if what
> I found is right, but now it seems if I implement
> what I thought was a fix I may burn up my Pert1.
>
> I've had low end stumbling (idle-2500 rpm) issues
> on my Corsa 140 since I finished it 500 miles ago.
> By consensus I was pointed to low idle circuits
> in the primaries, but blowing them out, etc.
> seemed to only help a little and temporarily. The
> problem always seemed almost mechanical to me,
> like at 2500 rpm a switch went on.
>
> This weekend I bypassed the resistor wire by
> running a wire from the battery to the coil.
> Boom! Problem solved! Like butta! So now I just
> need to bypass the resistor wire.
>
> Then I looked at the coil I was using (MSD). It
> measures only .7 ohm primary resistance. Looked
> it up in the catalog and that is the spec. So, no
> resistor wire and a .7 ohm coil. Dangerous to the
> Pert module according to this forum?
>
> I happened to have an old OE coil off a GTO, so I
> threw that in. It measured 1.5 ohm. With the
> resistor wire (1.8? + 1.5 = 3.3) it seems to work
> better than the MSD coil (1.8 + .7 = 2.5). So, if
> removing the resistor wire and using the MSD coil
> (0 + .7 = .7) seemed to work best (lowest
> resistance), why would the GM coil work better
> than the MSD with the resistor wire? Arrghhh!
>
> Maybe my next experiment should be using the GM
> coil and no resistor wire, happy medium? Maybe
> the MSD coil is a bad match with pert1?

well, resistance is only really part of the story here, there's also coil inductance. Inductance is a measure of how much the coil resists a change in current through it. Resistance is a measure of resistance to current. Inductance generally depends on the number of turns of wire, as well as the geometry of the coil and the core, if any. The rate at which current in an inductor changes is dependant on the voltage applied to it and the inductance. More specifically, V=L*di/dt (which is a bit of calculus, basically saying that the voltage in volts across the inductor is equal to the inductance in Henries times the rate of change of the current in amperes per second). There are generally two ways to apply this equation, you either have the inductor inducing a voltage when the current is forced to change, or you have the opposit, the current is changing due to a voltage placed across the inductor.

Anyway, the ignition system in your car works as follows:
1. distributors rotates and close the points, or the electronic ignition module turns on. At this point, t=0, you still have 'no current' in the coil. Since the points turned on, you now have the full electrical potential of the car across the coil, about 13 to 14 volts, minus the voltage drop of the resistor, which is 0 at this time since no current is flowing. (ohms law, V=IR, that is the voltage in volts across the resistor is equal to the current through it in amperes times the resistance in ohms). Also, this is where the capacitor (AKA, a "condenser") comes in. The capacitor stores energy and helps to stabilize the voltage at the coil at lower RPM's especially

2. as the current in the coil begins to rise because of the voltage placed across it, the voltage across the total resistance of the circuit also rises. This is also dependent on how discharged the condenser is.

3. this process continues and you get a roughly exponential rise of current in the coil with limit of current in the coil determined by the car's electrical system voltage divided by the total resistance of the ignition system. This would be the resistor, plus the coil resistance, plus any resistance by the pertronix in your case.

4. finally the distributor reaches the plug firing point, and your pertronix, or points if using a stock system go open circuit. This causes the coil to induce it's own voltage to resist the change in current. At this point, I should mention the high voltage secondary coil of the distributor is also an inductor, a much higher inductance one in series with the primary. The secondary and primary share a core, and therefore the magnetic field, and therefore are mutally coupled to each other.

so when the points turn off (or the electronic system), the primary coil's inductance resists the change in current and induces it's own voltage. The secondary, sharing a magnetic field with the primary, does the same. However, it's inductance is much larger, so for the same di/dt (rate of change of current) it generates a HUGE voltage, enough to cause a spark in the spark plug.

In addition to all of this, the coil stores energy within a magnetic field. This amount of energy can be determined with the equation E=I^2 * L
that is, energy in joules equals the current in amperes squared times the inductance in henries.

the amount of energy stored in the coil is partially what determines how strong the spark is, in addition to the voltage output of the secondary. Increasing current in the primary when charging the coil increases energy, voltage output, and spark strength. to increase the current, you can decrease inductance, which will also decrease your spark energy some, but maybe not as much as it increases from more current. On the other hand, decreasing the resistance also increases your current, without messing with the inductance.

Anyway, my final words after this wall of text are that an ignition system is WAY more complex than you might initially think. IMO, unless you want to spend a lot of time with trial and error, keep the original coil, resistor, plugs and their appropriate gap, and the condensers. The only thing I would mess with is replacing points. That's about the only thing that's simple here, since it's really just a switch.

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Re: Pertronix 1 Wiring
Posted by: cnicol ()
Date: May 28, 2015 11:47AM

Well, you could take three pages to describe the construction of a pencil but that doesn't mean it's all that hard to use one.

Pert 1 - pick a combination of coil and resistor that adds to about 3 ohms. Power the coil through the resistor but power the Pert with 12v and drive on.

Craig N. Coeur d'Alene ID.
66 Black Monza 4dr, 4.2L V8 49k
61 Seamist Jade Rampside 140 PG
60 Monza coupe (sold, sniff sniff)
66 Sprint Corsa convt - First car! Re-purchased 43 years later
2+2 gnatsuM 5691

+17 Tons of parts

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Re: Pertronix 1 Wiring
Date: May 28, 2015 12:10PM

Wow - I didn't realize using a Pertronix was so complicated. So much endless theory and so much fear. Maybe I should stop driving my Corvairs. They all have Pertronix 1 wired to the coil. Period. Been that way for years and tens of thousands of miles (Actually 100's of thousands of miles).

Now that I know this is all wrong I expect a failure soon. If i don't have a failure who should I blame? That's important.

Lon Wall
www.corvairunderground.com

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Re: Pertronix 1 Wiring
Posted by: davemotohead ()
Date: May 28, 2015 12:25PM

LOL Lon! Seems You and I are the only ones who wire them right to the coil with Resistor wire in place, Funny also, you and I are the only ones who seem to have never burned one up? The first 3 I ever bought are still in service running strong, wired right to the coil, the first one has worn out 3 engines! BUT, I have had cars come to me with a 12v bypass wire, and burned up pert, I took the bypass wire out and hooked a new unit right to the coil, Funny how they still run years later? eye rolling smiley

If I am doing it wrong, I don't want to be Right!smoking smiley







1960 4dr sedan caveman car
1961 Rampside (Chetside)
1962 Rampside (Barnside)
1962 Short Rampside (Shortside)
1962 Monza 700 Wagon
1963 Monza 900 coup (General Nader)

-----------------------------------
Rust Free Lancaster Ca

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Re: Pertronix 1 Wiring
Posted by: jzatarski ()
Date: May 28, 2015 12:36PM

cnicol Wrote:
-------------------------------------------------------
> Well, you could take three pages to describe the
> construction of a pencil but that doesn't mean
> it's all that hard to use one.
>
> Pert 1 - pick a combination of coil and resistor
> that adds to about 3 ohms. Power the coil through
> the resistor but power the Pert with 12v and drive
> on.


Hey, I never said don't mess with it, I just meant that you should be prepared to have to mess with it repeatedly if you do change it, until you find a combination that works well. Also, poor low end ignition performance could mean you need a bigger capacitor on the distributor, AKA a "condenser" (I really hate calling it that, personally, but that's what car guys know it as). Based on my electrical knowledge, that's seems to be a possibility. As a test, you can take a new condenser and put it in paralell with the current one.

But like I said, you'd just have to mess around with it. And as cnicol says, don't go too low on the resistance or you could slowly burn up your pertronix.

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Re: Pertronix 1 Wiring
Posted by: gjordahl ()
Date: May 28, 2015 01:55PM

jzatarski Wrote:
-------------------------------------------------------
> cnicol Wrote:
> --------------------------------------------------
> -----
> > Well, you could take three pages to describe
> the
> > construction of a pencil but that doesn't mean
> > it's all that hard to use one.
> >
> > Pert 1 - pick a combination of coil and
> resistor
> > that adds to about 3 ohms. Power the coil
> through
> > the resistor but power the Pert with 12v and
> drive
> > on.
>
>
> Hey, I never said don't mess with it, I just meant
> that you should be prepared to have to mess with
> it repeatedly if you do change it, until you find
> a combination that works well. Also, poor low end
> ignition performance could mean you need a bigger
> capacitor on the distributor, AKA a "condenser" (I
> really hate calling it that, personally, but
> that's what car guys know it as). Based on my
> electrical knowledge, that's seems to be a
> possibility. As a test, you can take a new
> condenser and put it in paralell with the current
> one.
>
> But like I said, you'd just have to mess around
> with it. And as cnicol says, don't go too low on
> the resistance or you could slowly burn up your
> pertronix.

Thanks for all the info. Seems like trial and error, along with a 3 ohm threshold total for safety. My thought was maybe my issue was with an MSD coil as well since I thought they used some sort of pulse current, but maybe I'm thinking that is out of the MSD box itself (which I'm not using).

a) "Power the coil thru the resistor..." got it, that's how it's setup now
b) "Power the Pert with 12V..." well the pert is powered off the + side of the coil, assuming that's what you mean?

Interesting comment on the condenser. Do I even have one using the pert? Been so long since I put it in I can't remember?

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Re: Pertronix 1 Wiring
Posted by: gjordahl ()
Date: May 28, 2015 02:09PM

gjordahl Wrote:
-------------------------------------------------------
> jzatarski Wrote:
> --------------------------------------------------
> -----
> > cnicol Wrote:
> >
> --------------------------------------------------
>
> > -----
> > > Well, you could take three pages to describe
> > the
> > > construction of a pencil but that doesn't
> mean
> > > it's all that hard to use one.
> > >
> > > Pert 1 - pick a combination of coil and
> > resistor
> > > that adds to about 3 ohms. Power the coil
> > through
> > > the resistor but power the Pert with 12v and
> > drive
> > > on.
> >
> >
> > Hey, I never said don't mess with it, I just
> meant
> > that you should be prepared to have to mess
> with
> > it repeatedly if you do change it, until you
> find
> > a combination that works well. Also, poor low
> end
> > ignition performance could mean you need a
> bigger
> > capacitor on the distributor, AKA a "condenser"
> (I
> > really hate calling it that, personally, but
> > that's what car guys know it as). Based on my
> > electrical knowledge, that's seems to be a
> > possibility. As a test, you can take a new
> > condenser and put it in paralell with the
> current
> > one.
> >
> > But like I said, you'd just have to mess around
> > with it. And as cnicol says, don't go too low
> on
> > the resistance or you could slowly burn up your
> > pertronix.
>
> Thanks for all the info. Seems like trial and
> error, along with a 3 ohm threshold total for
> safety. My thought was maybe my issue was with an
> MSD coil as well since I thought they used some
> sort of pulse current, but maybe I'm thinking that
> is out of the MSD box itself (which I'm not
> using).
>
> a) "Power the coil thru the resistor..." got it,
> that's how it's setup now
> b) "Power the Pert with 12V..." well the pert is
> powered off the + side of the coil, assuming
> that's what you mean?
>
> Interesting comment on the condenser. Do I even
> have one using the pert? Been so long since I put
> it in I can't remember?

Never mind on question b), answered my own question:

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Re: Pertronix 1 Wiring
Posted by: jzatarski ()
Date: May 28, 2015 02:45PM

also, I wanted to mention that normally a condenser is used for absorbing the inductive kickback of the coil, preventing arcing at the points. But in this case, it might help the low speed ignition performance. Like I said, worth a try, no?

EDIT: seems my first post didn't make it here, don't know what I messed up, must not have hit submit. Anyway, basically I said adding the condenser shouldn't *hurt* anything, so you might as well give it a try and see what happens.



Edited 1 time(s). Last edit at 05/28/2015 02:47PM by jzatarski.

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Re: Pertronix 1 Wiring
Posted by: jzatarski ()
Date: May 28, 2015 02:56PM

bah, had a brain fart. On my '66 (not sure about anyone else's) I have a condenser on my coil positive connection, as well as in the distributor. I've mixed up these. To be clear, I think you should try a capacitor (condenser) on the coil positive wire, that is after the resistor wire.

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Re: Pertronix 1 Wiring
Posted by: gjordahl ()
Date: May 29, 2015 05:46AM

jzatarski Wrote:
-------------------------------------------------------
> bah, had a brain fart. On my '66 (not sure about
> anyone else's) I have a condenser on my coil
> positive connection, as well as in the
> distributor. I've mixed up these. To be clear, I
> think you should try a capacitor (condenser) on
> the coil positive wire, that is after the resistor
> wire.

Appreciate the input. I know the condenser you're talking about. Always thought that was to reduce radio noise, or maybe that's the one on the voltage regulator (or both?). I think at this stage I'm going to go back to step 1. Install the original points and condenser using resistor wire and 1.5 ohm coil. I never ran the car in the original setup so I don't have a baseline. Then go from there.

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