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Coil polarity

  • balinwire
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12 Mar 2004 19:27 #1411 by balinwire
Replied by balinwire on topic plug info
That is a great idea about checking the Champion web page.

The web page for Champion is,
www.championsparkplugs.com/

This site is also very interesting, Federal Mogul.
www.federal-mogul.com/cda/site/b ... 01,00.html

They instantly found the H8 plug and it is a traditional plug, I guess this means old car. Go look at one and let me know what you think. Only 1.49.
It also said it was a resistor plug, very good page for plug questions, bookmark it.

That 40,000-volt Pertronix coil that you use can put out a spark! It must be a 12 v. system. No wonder the wires were breaking down. I am sure the 6v. Coil does not put out even half that much power.

The 812 service data chart of 1937 says the plug used should be a J9B with only a .025 ? gap. I have a lube chart that says use an H10 but that was probably a more available plug in the 40?s as it was used in the flathead Fords.

It did not occur to me to blast the plug and dye it. The Autolite replacement is black anodized but I did not like the large word Autolite printed on the porcelain area. It also did not have a screw end like the H8c.

I will also need to dial in the timing with a neon light with the timing marks and no 1# piston, front left, drivers side near bell housing? Like a Chevy V8.

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  • PushnFords
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11 Mar 2004 01:25 #1406 by PushnFords
Replied by PushnFords on topic Re: follow up on electrical tuneup
Balin-

If you go to the Champion website (and most other plug manufacturers) you will find a handy cross reference that also lists whether or not the plugs are resister. I've looked it up but can't tell you from memory what yours are. Autolite makes a black base plug or you might try lightly sandblasting and then use the cold blue stuff they sell for gun refinishing. It'll get you close to the correct look.

As for the plug wire ohms, I think you are a bit high. A good quality set of modern wires usually aren't over 10,000 ohms. I've seen cheap wires that will run around 15,000 but with a strong spark you will usually notice they are breaking down. I ohmed a lot of wires when I was changing a points car to electronic ignition. I was running a 40,000 volt coil, Pertronix, and Accel 8MM wires (black) and gapping the plugs at .050". It ran great but I went through several sets of wires before I found some that would last. On a solid strand wire like Cords use there is rarely over 500 ohms.

Derek

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  • balinwire
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11 Mar 2004 00:44 #1405 by balinwire
Replied by balinwire on topic follow up on electrical tuneup
I have been correcting the coil and another thing I have overlooked has been the plug wires and plugs. I now have 18 mm Champion H 8?s of unknown temperature but I think they run cold.
The original plugs were Champion H 10?s that had threaded plug wire ends <Top Type>and were black. These are not made currently <there is a huge demand, note to Champion>and the new H 10?s are H 10C?s that are silver in color and have clip on plug ends. These new plugs are probably resistor with a wider gap.
The closest plug I have been able to find is an H 8 Champion that has the correct narrow gap with the threaded wire end and may or may not be resistor.
This new plug that is such a perfect match except for the silver color. I would imagine the H10 of 1936 would be a 5,000 ohm plug. Could the new H8 be a 10,000-ohm plug that would be used with resistor wire? Is there an easy way to measure the resistance?
I have metallic high voltage wires. The total ohms in metallic wire and plug?s should be less than 5000 ohms.
A modern glass fiber and carbon cable should have no greater than 40,000 ohm?s and I would imagine they would degrade 6 v. performance.
I was next looking at the condenser. It causes the magnetic field of the coil to collapse creating the high voltage in the secondary windings. If the capacitor is incorrect or leaking it may also cause hard starting.
My car has not run long enough to see if the plugs run hot or foul. They have the usual carbon black coating from idling. A condenser can also result in short plug life if they are incorrect value.
The next area I will check in the ignition circuit will be the points and dwell.

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  • balinwire
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29 Feb 2004 02:01 #1361 by balinwire
Replied by balinwire on topic not reversed polarity, but overheating coil
Wow, it just appeared to me why they mounted the coil inside the cabin. It is cooler than inside the engine compartment. I got to hand it to the early designers, they really knew there stuff.

Also as usual everything Auburn did was perfect and cannot be improved be modern day tinkering.

It is getting hot and electrically shutting down. I have seen that on modern automobile computers if they overheat. I always wondered why they dash mounted the coil, I thought it was for the Electrolock type coil. I?ll bet it was for a cool place to hide it also

Guess time to go to the tractor shop for a 6v. Fordson firewall mount, brand new. She's gonna purrrrr' now.

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  • Pat Leahy
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28 Feb 2004 19:23 #1360 by Pat Leahy
Replied by Pat Leahy on topic Coil polarity
As Josh mentioned, the best solution is to go to NAPA and purchase a new 6 volt coil and mount it in the car a describe in past Newsletter. A fresh coil and a cooler place should cure the problem

Pat Leahy

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  • Josh Malks
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28 Feb 2004 14:39 #1359 by Josh Malks
Replied by Josh Malks on topic Old coil
Step one, Balin': throw away the old coil. They used shellac as the insulator which breaks down with time even in a box on the shelf. Much more so in use, with all that heat under the hood.

Start with a new, epoxy-sealed coil. Then at least you'll eliminate that component as a problem. And, the polarity markings will be visible.

When you get to authenticity issues, you can gut an original coil, mount it in its proper place in the hole in the firewall, and run the hi-tension lead straight thru it to the new coil mounted inside the car under the cowl.

Josh B. Malks
810 2087A
ACD Club Life Member
ACD Newsletter editor
Past president
www.automaven.com

Check out CORD COMPLETE at www.cordcomplete.com

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  • balinwire
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28 Feb 2004 02:16 #1357 by balinwire
Replied by balinwire on topic coil polarity
That is where the polarity comes into play; with the cold fuel intake charge would cool the electrode. With a positive charge at the center would require at greater voltage and the electrode would decay and cause harder starting.

That?s where the old gapper tools must have been used, interesting you remembered, I would like to see one of these tools. If everything is perfect slow starts are not noticeable but when things are old and the systems have marginal coils, starters, etc, all must be as correct as possible.

My car has an old replacement coil where the +&- signs are not noticeable and it might be a 6volt negative ground<if there is such an item> coil mounted to the firewall. It does make a hot spark; I am just trying to locate any weak spots in the ignition circuit.
<!-- s:oops: --><img src="{SMILIES_PATH}/icon_redface.gif" alt=":oops:" title="Embarassed" /><!-- s:oops: -->

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  • Hal Klassen
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27 Feb 2004 04:50 #1356 by Hal Klassen
Replied by Hal Klassen on topic coil polarity
I think the 20-30% loss in voltage is from having a coil connected backwards. The main reason neg. grd. is used, is with pos. grd., the side electrode eroded [remember the round plug gapping tools?] As to the tip temp., I don't think there would be any measurable difference.
Hal Klassen

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  • balinwire
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25 Feb 2004 01:43 #1348 by balinwire
Replied by balinwire on topic Where did the data go?
I noticed the engine cranking slowly and had several difficult starting sessions while the engine was warm.

After all the electric circuits were checked I looked to see if the coil terminals were grounded to the points.

Is there such a thing as a positive ground with the coil primary windings grounded to the coil case.

None of this matters if there is a spark at the coil.

I then remembered that it takes 20-40% more voltage to fire a plug electrode that has reversed polarity. It will result in hard starting, missing and poor performance. Could I have reversed the coil in series to the breakers?

A negative ground car must always have negative polarity to the spark plug center electrode. Would a positive ground car have a positive polarity at the center plug electrode?

Electrons will move from a hot object to a cold object at lower voltages. The center of the plug would be hotter than the electrode.

That is why I thought there might be a special coil that may have -, negative windings. Could an incorrect coil be reversing the ground to the plug.

This must be why there was a change in groundings in 48. They would get negative at the plug center easily.

To check coil polarity use a voltmeter from plug wire to ground and see which way the needle sweeps. Just having touble thinking in reverse polarity, everything is negitive nowdays. - + - + - + <!-- s:wink: --><img src="{SMILIES_PATH}/icon_wink.gif" alt=":wink:" title="Wink" /><!-- s:wink: -->

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  • Auburn/Cord Parts
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24 Feb 2004 14:35 #1346 by Auburn/Cord Parts
Replied by Auburn/Cord Parts on topic Re: Update that data!

balinwire wrote: I am interested in coil polarity on positive ground cars and its primary and secondary windings in the coil and the polarity of the high voltage wire tower. Should a positive ground car have the spark plug with a positive or negative ground? Is there special coil for + ground frames.


The old standing rule of thumb for positive ground batteries is positive wire to the distributor points from the coil. Most 6 volt systems were positive ground prior to 1949.

Stan

Auburn/Cord Parts, Inc. P.O. Box 547 1400 N. "A" St. Wellington, KS 67152 (620) 326-7751 This email address is being protected from spambots. You need JavaScript enabled to view it.

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  • balinwire
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20 Feb 2004 22:52 #1340 by balinwire
Update that data! was created by balinwire
I do not know if any of these old part numbers are valid #?s but this is a very good example of how this valuable information can be relayed via .pdf files and printed.

There are some great old repair manuals with descriptions of where things go and what it takes to make them tick. I have some great old info on Startex information that I would like to scan. I could then share this old article via Adobe pdf?s on this post area.

I am interested in coil polarity on positive ground cars and its primary and secondary windings in the coil and the polarity of the high voltage wire tower. Should a positive ground car have the spark plug with a positive or negative ground? Is there special coil for + ground frames.

Anyone who has files on .pdf format please post them as they are very interesting to view. Post-post-post <!-- s:!: --><img src="{SMILIES_PATH}/icon_exclaim.gif" alt=":!:" title="Exclamation" /><!-- s:!: -->

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