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Re: Need Help - Coil voltage values?
Date: July 10, 2018 03:47AM

Dale's description of "Dangerous" mis-matched parts applies to the ignition system.
Dangerous to the resistor wire in the harness for example - it will overheat!
Dangerous to the points ignition system - they can burn
Dangerous to the transistor/electronics of a Pertronix - they can also burn

All from excessively high current (amperage)

The wires from the key switch on the on the dash (ignition switch) supply two different voltages to the Corvair ignition coil. ~12 volts during the starting phase and ~6 volts in the "running" phase.
There are two separate wires attached to the + terminal of the coil. Only one of them is active during each phase
~12 volts is reduced by the 1.8 ohm resistance wire installed in the engine wiring harness to ~6 volts.
If you are seeing less than ~6 volts at the coil + terminal when the engine is running, it's likely that the multiple connections in the wiring harness between the battery to the ignition switch then back to the engine are adding more resistance, causing the voltage to drop.

A way to fix this is to rewire the circuit using relays to directly the battery 12 volts to a 1.8 ohm resistor and then to the coil. The wire from the ignition switch then just activates the relay.
You should also install a relay to the starter solenoid "S" terminal. Again to allow the solenoid to get voltage directly from the battery instead of the old wiring up to the ignition switch and back.


Dan Davis ~ Pierce County, WA ~ CORSA Western Director + Corvairs NW + North Cascades Corvairs + Corvanatics
1966 Corsa Turbo coupe ~ ~ 1966 140 Corsa ~ ~ 1965 Monza 140/4 'Vert Sierra Tan/Fawn ~ 1964 Monza 'Vert (SOLD) ~ 1960 Monza Ermine White/Red PG ++ ~ 1965 Monza 140/4 Evening Orchid w/ ivory/black interior ~ 1962 Monza Wagon 102/4 ~ 1963 Rampside/Scamper ~ 1963 Red/Greenbrier ~ 1969 Ultra Van #468

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Re: Need Help - Coil voltage values?
Posted by: red monza ()
Date: July 10, 2018 07:08AM

All of this talk about a coil....goodness.

Simply put...the coil from NAPA(Echlin brand, one of the best)that fits a 1957 Buick, a 66 Corvair, a 68 Corvette, and just about any GM car with points and a 12 volt system is a IC 12 coil...same, same, same. It says must use an external resistor with this coil....our corvairs have this built in in the factory wiring.Hook this wire to the + on the coil ( if you are a non believer of facts, open up the wiring harness and you will see a cloth covered wire hidden...that is your resister wire). A black wire runs from the - side of the coil to the points and condenser.

Put the points on 33 dwell or use a 15/1000 metal feeler gauge to gap the points. Then set the timing to about 2-4 degrees more than is called for in the books as a beginning setting. Put in some premium gas...and enjoy many miles of smiles.

If you put 12 volts constant to the points, you will end up with posumm cod blue points shortly with arms that are melted together.If you are averaging 5-8 volts to the points you are fine while idling...can the coil handle a full 12 volts...yes, yes it can. Every time you engage the starter, you are sending a full 12 volts to the coil making the car easier to start. The starter has an I on it and that is the source of the full 12 volts.

I wired my 49 Chevy Fleetline from scratch, as I have all the street rods I have built, and it did not come with a factory resistor wire and I did not use an HEI 12 volt distributor due to problems with an electric speedometer. I put in a 50's ceramic resistor, mounted on the fire wall to lower the voltage to the points.

As far as averaging goes...the gas gauge on older cars have a resistor so to speak...it gets 12 volts, then zero, then 12, then zero, and it averages 6 volts. I have had to wire in this control on two of the 3 street rods. This stablizer came from 70-80's ford pickups...I still have a spare one downstairs from a Lincoln Continental.

All of my coil/points cars run extremely well( all four)....start well...maybe a video of them would be nice...even improve the L-79 big block eater 68 Corvette one....terrible sound from that old cell phone video.

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Re: Need Help - Coil voltage values?
Posted by: Spectre ()
Date: July 10, 2018 07:11AM

As I asked before, if the car was running great, why were voltages checked anyway? Don't fix what is not broken. Drive on and enjoy!

David Clamp


1965 Corsa convertible - 140 4spd/3.55/AM-FM

2013 Mustang GT convertible - 5.0, 6spd auto, Procharger i-1

2003 Miata SE - 6spd manual (wife's toy)

"Victory is mine!" - SG

Oklahoma City, OK

Click for Oklahoma City, Oklahoma Forecast

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Re: Need Help - Coil voltage values?
Posted by: oldqmguy ()
Date: July 10, 2018 09:12AM

Thanks to Dan for answering the "dangerous" question! grinning smiley

Over the years I have repaired and or replaced enough 'burnt up' wiring harnesses (Corvairs and other Hot Rods) to understand the term Dangerous.

Depending on 'what' has been changed (including wires that are not big enough for the intended load) points get 'welded' together, coils melt, wires overheat and fires occur when you least expect it.

I just want people to understand "how" the electrical stuff works, and "why" the components are used. I cringe every time I see a rubber hose fuel line in the engine compartment or see a really bad wiring job!

Corvairs are fun but we do need to keep them safe! eye popping smiley

Thanks for listening!!! smoking smiley

Dale cool smiley

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: Need Help - Coil voltage values?
Posted by: red monza ()
Date: July 10, 2018 09:47AM

Spectre Wrote:
-------------------------------------------------------
> As I asked before, if the car was running great,
> why were voltages checked anyway? Don't fix what
> is not broken. Drive on and enjoy!

I completely AGREE....!!!

And oldqmguy.....my cringe worthy is seeing those cheap made in China clear plastic fuel filters in the engine compartment just waiting for you to put in a total loss claim.

When I wired all of mine, one had 30,000 on it when it went to NJ, I always used much heavier gauge wire than called for...those that use the "kits" are the ones that are at risk as the wires are so much smaller than what is considered safe.

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Re: Need Help - Coil voltage values?
Posted by: 66vairman ()
Date: July 10, 2018 09:56AM

This LONG post does point out how little most folks know about the Corvair ignition system.

Dale makes a point about dangerous. I got a call from a club member about a hot electrical smell in his engine compartment. The local Corvair "expert" told him to install a Petronix Flamethrower II 0.6 ohm coil for a HOT spark. While GM used many coils, almost all had about 1.3 ohms of primary resistance and with a 1.8 ohm ballast for a total of about 3.1 ohms. The Flamethrower II coil at 0.6 ohms was causing excess amperage and was overheating the Corvair ballast wire. Not good. I asked the owner if the car ran fine with the stock coil and he said yes. I put the stock coil in and problem solved.

The late Bob Helt with others published a CORSA article with a admittedly basic coil test and found most of the so-called HIGH voltage coils were not better than the Corvair coil. Today there is little variety, but on non-turbo Corvairs a good 1960's Chevy V8 coil replacement works fine.

I've also seen incorrect ceramic ballast resistors installed. There a literally dozens of values available for different cars. It must be 1.8ohm.

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Re: Need Help - Coil voltage values?
Posted by: thewolfe ()
Date: July 10, 2018 10:05AM

It is also worth noting that there are more than one flamethrower coil. The .6 ohm version(flamethrower 2) is only to be used with the pertronix 2. The standard flamethrower coil is 1.5 ohms and is to be used with pertronix 1 or stock ignition.

Nate Wolfe
Portland OR
65 Corsa 180

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Re: Need Help - Coil voltage values?
Posted by: 66vairman ()
Date: July 10, 2018 10:07AM

red monza Wrote:
-------------------------------------------------------

>
> As far as averaging goes...the gas gauge on older
> cars have a resistor so to speak...it gets 12
> volts, then zero, then 12, then zero, and it
> averages 6 volts. I have had to wire in this
> control on two of the 3 street rods. This
> stablizer came from 70-80's ford pickups...I still
> have a spare one downstairs from a Lincoln
> Continental.
>

Red Monza that's a new one on me, but I don't get into the Ford stuff. Do you have any articles to back that up?

Maybe Ford used a simpler (less expensive) gauge and controlled the gauge supply voltage separately. That is the norm today with computer controlled instrument panel voltages.

The Corvair fuel gauge resistor gets ONLY DC voltage from the battery/alternator via a fuse. The gauge resistor is a simple load with a reference coil to balance the gauge circuit so system voltage fluctuation do not cause the gauge to change as was common on some early cars that only used a single coil to drive the needle (less expensive gauge).

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Re: Need Help - Coil voltage values?
Posted by: oldqmguy ()
Date: July 10, 2018 10:37AM

What most folks don't know is exactly 'how' the actual "Ignition System" works.

The idea is to generate an electrical arc across the spark plug gap, at the proper time (and on the proper plug) to ignite the air/fuel mixture in the cylinder.

This is done using a device generally called "the coil" (it is an "autotransformer") that converts low voltage (~6 volts) pulses to very high voltage pulses.

A standard (1960's type) 'coil' will produce an open-circuit voltage of about 30,000 volts! Again, this is "open-circuit" so no arc is being drawn.

The interesting part about the coil output is that it STOPS rising when the plug 'fires' (the arc starts)! Most plugs in a well running 1960's engine fire between 15,000 and 25,000 volts.

Example: New set of plugs and points, perfect setup. The plugs fire at 15,500 volts. The coil output STOPS RISING AT 15,500! Three thousand miles later the plugs are not so good, the points are worn and it now takes 21,000 volts to get the plugs to fire. Again, the coil output STOPS RISING when the plugs fire.

In real life, the coil output varies with each cylinder because all plugs don't wear the same.

What I am trying to point out is that a "High Voltage Coil" is not necessary for normal operation. I know that some try to sell them as a 'fix' for a poor running engine but this is not a real 'fix' and can cause many of the problems we have been talking about. Like the 'normal' coil, the output of a High Voltage Coil will STOP RISING at the time a plug fires (if the plug fires at 16,000 volts that is where the output voltage stops). So a "60,000 Volt Coil" is a waste of time and money unless you are building a Racing Engine that takes a much higher voltage to fire whatever 'plug' you are using!

Dale cool smiley

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: Need Help - Coil voltage values?
Posted by: red monza ()
Date: July 10, 2018 10:40AM

In 40 some years...I have NEVER had a points problem, a coil problem, a wiring problem with any of my street rods... and my Corvette with factory wiring, has never had a wiring problem.

This sorta says it all about some of these posts....

My first street rod was a 55 Ford F-100, I built the 305 Chevy and when I installed it, I put in a Dodge Charger radiator as it was a donor car due to the torsion bar suspension...one of my friends said you can't do that...I laughed and said why not...does the radiator know its a Chevy engine....LOL....yeah it worked fine until I got the orig rad re-cored which was about a year later and many many miles of trouble free miles with the Dodge radiator.

Next came my 51 Ford car....I bought a NOS 1951 6 cylinder Ford radiator to go in the car....you can't put that in your car...it has a Chevy V-8....really I said. I just won't tell that ford 6 cyl radiator it is cooling a Chevy v-8. I kept very very quiet. In 8 years, the highest I saw the temp get was a little over 200 coming up a very steep mountain from SC.

So, some of you better tell me that I did wrong....LOL

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Re: Need Help - Coil voltage values?
Posted by: red monza ()
Date: July 11, 2018 05:45AM

66vairman Wrote:
-------------------------------------------------------
> red monza Wrote:
> --------------------------------------------------
> -----
>
> >
> > As far as averaging goes...the gas gauge on
> older
> > cars have a resistor so to speak...it gets 12
> > volts, then zero, then 12, then zero, and it
> > averages 6 volts. I have had to wire in this
> > control on two of the 3 street rods. This
> > stablizer came from 70-80's ford pickups...I
> still
> > have a spare one downstairs from a Lincoln
> > Continental.
> >
>
> Red Monza that's a new one on me, but I don't get
> into the Ford stuff. Do you have any articles to
> back that up?
>
> Maybe Ford used a simpler (less expensive) gauge
> and controlled the gauge supply voltage
> separately. That is the norm today with computer
> controlled instrument panel voltages.
>
> The Corvair fuel gauge resistor gets ONLY DC
> voltage from the battery/alternator via a fuse.
> The gauge resistor is a simple load with a
> reference coil to balance the gauge circuit so
> system voltage fluctuation do not cause the gauge
> to change as was common on some early cars that
> only used a single coil to drive the needle (less
> expensive gauge).

First of all, there is a HUGE difference in skills and intellect needed in the successful building of a street rod vs. building/repairing a Corvair...this is why I bought a Corvair to play with, much much easier to work on... and most aftermarket street rod stuff is now China junk or American junk. Most street rods take about 4-5 years to build as my 49 Chevy did and about $30,000.00 to build one like mine doing 95% of the work on it myself...even paint.

In building a street rod, you ask yourself and research just about EVERY task you will be doing?

What suspension will I need to install, is a 2nd gen Camaro too wide, where do I cut the original frame, the donor frame, what angle when welded in will be needed to make the car driveable and handle well. What tilt steering column will fit and work with this sub-frame? etc etc etc just for this one task.

What rear end? Transmission? Engine? Braking system? Power window and how to custom make the brackets that are not avaiable? Interior material? Style? If roll and pleat, how far are the pleats from the next one? Power antenna? What style...frenched? surface mount? My 49 received a surface one from a late 80's Porche. Where will the switch be for its control? Will the overhead and A pillar be able to handle the additional wire?, etc. There are NO BOOKS, NO INSTRUCIONS on most of the tasks...just your brain and acquired know how. It would take me over an hour to list all the different parts I used in building my 49 Chevy Fleetline....hundreds of non-1949 Chevy parts.

Do you get the picture....you just don't pick up the phone and call Clarks, remove a screw or bolt and install a part.

Now for your question....the 55 f-100 was my first street rod, I had gone to the F-100 NATIONALS in Tn. One super nice guy had built his truck as I wanted mine to be just like his... he had used the ORIGINAL instrument panel, but put in 85 Mustang gauges which fit in the orig panel with little mods...he said you must use an IVR....that is the name of the part that gives 12 volts, 0 volts,12-0,12-0....so yes ford gauges...but not CHEAP gauges. I also used this IVR on my 51 ford as you would NEED if you used orig 6 volt gauges in a 12 volt system as I wanted to leave the orig instrument look to the car....another decision you see.

You can google IVR instrument or read the book I am showing you.

If you were trying to question my knowledge or experience....that was a big MISTAKE....if you were trying to expand your knowledge of something you were not aware of...good for you.

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Re: Need Help - Coil voltage values?
Posted by: red monza ()
Date: July 12, 2018 04:37AM

By the way...the B and W photo of the $75.00 55 F-100 is the blue truck after 6 long years...that was my first one. I wired it from scratch and it even had a power cowl vent.

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Re: Need Help - Coil voltage values?
Posted by: 66vairman ()
Date: July 12, 2018 09:39AM

Red Monza - I just asked a simple question.

Don't threaten me about questioning your knowledge as a BIG MISTAKE.

Don't need to hear how great you are.

Go take your medication.

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Re: Need Help - Coil voltage values?
Posted by: joelsplace ()
Date: July 12, 2018 10:32AM

Red Monza - that is a terribly complicated way to say mechanical voltage regulator.
I found a site that says Ford used them all the way to 1988. Junk! Corvairs have better technology than 80s Fords. Why would anyone continue to make 6V gauges that long?

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