(800) 853-2651
SHOP NOW

6V vs 12V coil

R

rrlund

Well-known Member
I all actuality and reality,is there such a thing as a 6 volt or 12 volt coil in a Delco distributor ignition system?
I know about using a balast resistor if you change one from 6 to 12,but I have 6 gas tractors here. Two six volt,four 12. Three of the 12s are that way from the factory,one has been changed from 6.
I can't find anything on any of those coils that say 6 or 12 volt. None of those tractors has an external balast resistor. Not even the one that's been changed from 6.
 
I looked closely at the coil on my Farmall 300 project and found that it does faintly say 6V, I think it was on the end if I recall correctly.
Zach
 
alot of them werent marked,but yes theres a difference.the difference is the resistance in the coils themselves.I have a 52 8n tractor thats been converted and it uses no resistor at all but when i rewired it i bought a 12volt coil designed to use no resistor. When i bought it it had the original 6volt coil with resistors.neither coil was marked as I recall( been a while).I had a bro in law that bought a kit somewhere to convert his.it came with a 6volt coil and a length of resistor type wire. no telling how many ways these things have been hooked up,over the years.but in answer to your question yes theres a difference for long point/coil life.
 
(quoted from post at 13:22:47 07/10/12) I all actuality and reality,is there such a thing as a 6 volt or 12 volt coil in a Delco distributor ignition system?
I know about using a balast resistor if you change one from 6 to 12,but I have 6 gas tractors here. Two six volt,four 12. Three of the 12s are that way from the factory,one has been changed from 6.
I can't find anything on any of those coils that say 6 or 12 volt. None of those tractors has an external balast resistor. Not even the one that's been changed from 6.
Click to expand...

Near as I can figure out, ALL ignition coils are 6 volt. If the vehicle it is in IS a 6 volt battery system, then all is good and nothing else is needed. IF however the vehicle is a 12 volt system, then something needs to be in place to reduce the 12 volts down to just 6 volts. Usually that is accomplished by adding an EXTERNAL resistor, but it can be accomplished also by adding the resistance INSIDE the coil, so an external resistor is not needed. Those coils will usually be marked as "12 volt, no external resistor required", but it is possible I suppose that over time the printing will be worn off and then it would be nearly impossible to identify. Also, those external resistors come in many different forms. Just because you don't see one of those common, ceramic block resistors somewhere, doesn't mean there is NOT an external resistor or resistance incorporated into the wiring.
 
There are coils for 12 volt use with no ballast. My '56 Plymouth has one, and no ballast shows on the wiring diagram either. Original factory wiring. I run the same coil on 12 volt or 12 volt conversion tractors.

Ask any good counterman about a 12 volt coil that requires no ballast. NAPA has several.

Josh
 
the presence of an 'internal resistor' would be counter productive and wastefull.

simply winding theprimary with the correct # of turns and correct diameter of wire will create the correct primary resistance that the application is targeted for.

that's the difference in an ic8 vs an ic14

soundguy
 
(quoted from post at 17:22:47 07/10/12) I all actuality and reality,is there such a thing as a 6 volt or 12 volt coil in a Delco distributor ignition system?
I know about using a balast resistor if you change one from 6 to 12,but I have 6 gas tractors here. Two six volt,four 12. Three of the 12s are that way from the factory,one has been changed from 6.
I can't find anything on any of those coils that say 6 or 12 volt. None of those tractors has an external balast resistor. Not even the one that's been changed from 6.
Click to expand...

This is an IH coil for 12v and I have seen several Delco's marked as 12volt

9108.jpg
 
There is INDEED a difference. If you go to NAPA and ask for a coil they will ask if you want a 6 or 12 volt, they WILL NOT SAY WE ONLY SELL ONE FOR 6 OR 12 THEYRE ALL THE SAME !!!!!!!!! (yeah right)

a) There are coils designed for operation at 6 volts nominal that will handle the current, dissipate the heat and produce a spark at cranking voltage which may be 4.5 volts yet still operate at charging voltages of 7 volts, their LV primary winding resistance will be in the neighborhood of 1.25 to under 2 ohms, many around 1.5.........

b) Therre are coils designed for operation at 12 volts nominal that will handle the current, dissipate the heat and produce a spark at cranking voltages of 9 volts yet still operate at charging voltages of 14 volts, their LV primary winding will be in the neighborhood of 2.5 to under 4 ohms, many around 3 ohms............

I challenge anyone to find a coil labeled 6 OR 12 volts (yeah right). Coils may be labled 6 volts,,,,,,"12 volts for use with an external ballast resistor (or requires ballast)" or "12 volts NOT for use with ballast (or no ballast required)......

HOWEVER many 6 and 12 volt tractors still uee the same 6 volt coil butttttttttt if on a 12 volt tractor they add an external series voltage dropping (12 to 6) ballast resistor which drops 6 volts leaving 6 on the coil as a 6 volt coil is designed for DUHHHHHHHHHHHHHHH

So go to NAPA and see if they have "6 or 12 volt" coils?????????? NOOOOOOOOOOOO they make em to operate at 6 ORRRRRRRRR 12 volts NOTTTTTTT whichever you happen to like lol

John T Electrical Engineer
 
I recently replaced the 6 volt coil on my 1940 IH farm truck. Postivie ground machine, coil has a neg and pos terminal. The original wasn't marked. I put the neg to the power and the pos to the distributor if I remember right. Is that correct since I'm sure it matters???? Guy at the part store wasn't sure. Said it had been too long since anyone asked him a question like that and he just didn't remember any more.
 
I bought a coil that has printed on the case:
"STRAIGHT 12 VOLT". I don"t use any resistor, as I figured none was needed. (14 years-no problem)
 
You can get 6v ones and 12v ones it will usually say on the coil or box whether it need a resistor it all depends where you buy it thats been my expereince.
 
Thats correct, a 12 volt coil is designed to operate at 12 volts WITH NO BALLAST

Thats why you had no problem

John T
 

John t, my unmarked coils ohm for 6 volt and my coils marked 12 volt ohm for 12 volt and I do not use a resistor on them.

I ohm any unknown coil before installation.

The IH coil I pictured was sold to me as 6 volts by a seller who did not know that IH made the barrel shaped coils in both 6 and 12 volt. (seller made good on the deal and I kept the 12 volt for future use), I caught the error because I hit it with the Fluke since the 12v stamp was hidden under the old paint.
 
(quoted from post at 23:41:26 07/10/12) I recently replaced the 6 volt coil on my 1940 IH farm truck. Postivie ground machine, coil has a neg and pos terminal. The original wasn't marked. I put the neg to the power and the pos to the distributor if I remember right. Is that correct since I'm sure it matters???? Guy at the part store wasn't sure. Said it had been too long since anyone asked him a question like that and he just didn't remember any more.
Click to expand...


Wrong. Polarity does matter. Many phantom hard staters are solved when the coil is wired properly.
 
(quoted from post at 15:03:16 07/11/12)
(quoted from post at 23:41:26 07/10/12) I recently replaced the 6 volt coil on my 1940 IH farm truck. Postivie ground machine, coil has a neg and pos terminal. The original wasn't marked. I put the neg to the power and the pos to the distributor if I remember right. Is that correct since I'm sure it matters???? Guy at the part store wasn't sure. Said it had been too long since anyone asked him a question like that and he just didn't remember any more.
Click to expand...


Wrong. Polarity does matter. Many phantom hard staters are solved when the coil is wired properly.
Click to expand...
eah, B&D..& many have been started by holding one's mouth just right, too. Spark polarity is virtually insignificant (totally in practice).
 

Once again it seems we have discussed this issue far beyond what was necessary which has resulted in way more confusion and questions than actual, knowledgeable answers.
 
Your statistics are where? The increase in output
voltage with proper vs. wrong polarity are well
known.
During compression stroke the when the starter is
drawing it's most. Is also when the coil has to
produce enough spark energy and voltage to jump the
gap.
There is no voltage to spare on older,worn or out
of tune engines.
 
(quoted from post at 21:22:38 07/11/12) Your statistics are where? The increase in output
voltage with proper vs. wrong polarity are well
known.
During compression stroke the when the starter is
drawing it's most. Is also when the coil has to
produce enough spark energy and voltage to jump the
gap.
There is no voltage to spare on older,worn or out
of tune engines.
Click to expand...
"The increase in output
voltage with proper vs. wrong polarity are well
known. "...........only in b&d's head! Dont need any stinking statistics......just simple facts! There is no difference in voltage or energy, just polarity, which makes zero difference with cold, start-up electrodes. Can you say, "analyze the circuits"?
 
Just to add some confusion and put some gas on the fire.

Some 12V's had a 6v coil wired through a balance resistor for normal operation and had a seperate wire that gave the coil the full 12v during cranking.
 
Leej I have no idea why you have taken such offence and
have your knickers in such a twist over coil polarity.
Not only is output voltage increased as a portion of the coil
is not " bucking" . Do you know what kind of surfaces a spark
prefer to jump to and from ?
 
(quoted from post at 19:42:16 07/12/12) Leej I have no idea why you have taken such offence and
have your knickers in such a twist over coil polarity.
Not only is output voltage increased as a portion of the coil
is not " bucking" . Do you know what kind of surfaces a spark
prefer to jump to and from ?
Click to expand...
WWOOOOOOPPPPEEEE WHOOO!!!
1% ain't gonna do jack sheet!!!!!!!!!! 200 out of 20,000 open circuit!!!
And to beat that, the gap & pressure sets the arc voltage & it is more like 1000 to 2000, so the 200 is more, repeat more than totally swamped!
As I said, IT DOESN"T MATTER!!!!!!!!!! Even others have tried to beat it through your thick skull, that most mags & many, many modern wasted spark engines operate on BOTH pos & neg spark all the time, day in & day out. Go study phase converters....you need better understanding there too.
I sense a lack of full understanding it your postings on that topic too. :roll:
 
Plain surface or a point for ideal electrical
entry and or exit ?
The wasted spark ignition system have designed
in more secondary voltage than conventional.
In a borderline starting application, 1 or 2
thousand will make or break attempt.
Phase converters are a compromise that sort of
work good enough in most applications.
The distorted phase angles of the voltage and
current are the cause of wasted input power and
reduced output power.
With the falling prices of VFD"s a mechanical
phase converter has lost it"s advantages.
 
(quoted from post at 00:19:36 07/13/12) Plain surface or a point for ideal electrical
entry and or exit ?
The wasted spark ignition system have designed
in more secondary voltage than conventional.
In a borderline starting application, 1 or 2
thousand will make or break attempt.
Phase converters are a compromise that sort of
work good enough in most applications.
The distorted phase angles of the voltage and
current are the cause of wasted input power and
reduced output power.
With the falling prices of VFD"s a mechanical
phase converter has lost it"s advantages.
Click to expand...

"The wasted spark ignition system have designed
in more secondary voltage than conventional."......another one of those "facts in b&d's mind', or can you prove it?
1000 or 2000 may make a difference, too bad for your argument that 200 just won't make or break!
Done correctly, there are no distorted phase angles. I've seen your diagrams & they are flawed, sir! Don't need an artist rendering of what's in his mind, just a dual channel oscilloscope to see what is really there.
 
Three channel scope shows all the phase angles.
You have to compare the phase angles of both current
and voltage on all three phases.
Look at the 180 degree phase angle applied. How
do you bend it to 120 degrees?
Lets see you facts ?
Have you ever tested a coil's capacity forward and
rev polarity with an actual measured gap?
 
(quoted from post at 03:22:17 07/13/12) Three channel scope shows all the phase angles.
You have to compare the phase angles of both current
and voltage on all three phases.
Look at the 180 degree phase angle applied. How
do you bend it to 120 degrees?
Lets see you facts ?
Have you ever tested a coil's capacity forward and
rev polarity with an actual measured gap?
Click to expand...
've looked at current, I've looked at voltage, I've looked at all 3 phases, I've seen light, I've seen dark, I've seen day.
" Look at the 180 degree phase angle applied. How
do you bend it to 120 degrees?" Right there! Let a guy talk long enough & he will show what he doesn't know. You are NOT, repeat NOT applying "180 degrees" to bent to 120!!!!!!! When you connect L1 & L2 to A & B of a 3 phase (A,B,C) motor, you are connecting NO neutral, so there is no "180 degree" involved.
Looking only L1 to L2, there is NO phase angle to be seen, measured, or discussed...........in order to have a phase angle you MUST have two waveforms to compare. L1 to L2 is a SINGLE waveform my friend! The motor acting as phase converter produces "C", now & only now do you have more than one waveform to compare....you can now compare the wave form seen across A to B, to the waveforn seen across A to C and the wave form seen across B to C. They will be 120 relative to one another..............no 180 to be seen. You are either just trying to jerk me around, trying to save face from your recognized mis-statements, or you just don't really understand how this works.
 
If looking at it across a Delta and from that
perspective then yes if just energizing one
winding.
Output will be at best 57.7% of the rotary
converters nameplate rating.
The other two legs will still come up with
lower voltages and currents. Capacitors across
those two legs can be a bandade solution.
The driven load will not be able to make rated
HP without overheating and noise/vibration.
Things is, why bother being a luddite when a
VFD will provide soft start, variable rpms, max
torque limiting if desired and true clean power?
 
(quoted from post at 13:06:15 07/13/12) If looking at it across a Delta and from that
perspective then yes if just energizing one
winding.
Output will be at best 57.7% of the rotary
converters nameplate rating.
The other two legs will still come up with
lower voltages and currents. Capacitors across
those two legs can be a bandade solution.
The driven load will not be able to make rated
HP without overheating and noise/vibration.
Things is, why bother being a luddite when a
VFD will provide soft start, variable rpms, max
torque limiting if desired and true clean power?
Click to expand...
If looking......". Well, bud, that's all you need to look at.
You call it a 'bandaid', others will call it 'properly designed".
Done correctly, it will produce full power without noise & vibration & overheating. Do a half a$$ed job & you get half a$$ed results. Efficiency will vary with design/implementation, but even if lower than optimal, the limited use of hobbiest more than off sets additional cost of a high efficiency converter.
Back to the original topic........you still haven't found those extra several thousand volts of spark when connected -/
+ vs +/-, have you? stop looking, you won't. Your time will be better spent looking for another "face saving diversion'. :wink:
 
Use one of those variable gap voltage testers with both
polaritys and get back to me on what you found.
What do you have against a vfd ?
A 10HP three phase motor supplied with single phase and
used as a phase converter can not power a 10HP three phase
motor at full load. Both the converter and load motor will over
heat .
The third leg has a lower unbalanced voltage and
unbalanced current.
 
(quoted from post at 01:50:08 07/14/12) Use one of those variable gap voltage testers with both
polaritys and get back to me on what you found.
What do you have against a vfd ?
A 10HP three phase motor supplied with single phase and
used as a phase converter can not power a 10HP three phase
motor at full load. Both the converter and load motor will over
heat .
The third leg has a lower unbalanced voltage and
unbalanced current.
Click to expand...
b&d said, "A 10HP three phase motor supplied with single phase and
used as a phase converter can not power a 10HP three phase
motor at full load."
No sheet Sherlock! Almost any homeless bum living in a cardboard box, under the bridge knows that! I'm once again IMPRESSED!!! :roll:
 
To quote you "
Done correctly, it will produce full power without
noise & vibration & overheating. " Unquote
You said nothing about 57.7% a best and less than
50% real world.
 
I don't care if it is 40% !!

Back to the original topic........you still haven't found those extra several thousand volts of spark when connected -/
+ vs +/-, have you? stop looking, you won't. Your time will be better spent looking for another "face saving diversion'. Wink
 
(quoted from post at 19:08:07 07/15/12) Since when did any of your posts actually had
electrical topics as the priority?
Click to expand...
trange way to divert or duck out of a loosing position bud
 
(quoted from post at 22:14:03 07/15/12) So you did prove my point.
Now go out there with a gap style coil voltage
tester and try both polarities.
Click to expand...
H, yes!!!!!!!!!!!!!
did rig rig up the adjustable spark gap, ran the old IH coil both ways and I sure did prove a point! That b&d is DEAD WRONG!!!!!!!!!!
Connected originally as it was 6v pos ground , I got a neg polarity spark as expected & set gap screw to maximum that it would arc. Then, reversed battery connections on tractor & repeated and spark now has pos polarity and maximum gap setting that it will arc across is still same. So, same voltage just reversed polarity!!! Next, I reversed the two primary wires on coil & repeated and now I once again have a neg spark polarity, but the gap had to be closed inorder to obtain an arc. So, if you want the neg polarity, you have to give up spark voltage in exchange. Thus it is shown!
Circuit analysis had long ago shown this & except for those that haven't performed same, the imperical approach wasn't necessary or worth all the effor to disconnect, reconnect coil & generator (didn't want to re-polarize). Now, IF it is really important to you about those couple hundred volts & neg polarity (that is, you want tnem BOTH), then you can purchase a coil for a tractor that was factory Neg ground & it will have the correct winding sense (primary rel to secondary) to provide BOTH the higher voltage AND correct polarity.
So, what is your escape route now b&d???
You might actually learn something here, unless you are beyond the learning stage.
 
(quoted from post at 16:47:23 07/15/12)
OH, yes!!!!!!!!!!!!!
did rig rig up the adjustable spark gap, ran the old IH coil both ways and I sure did prove a point! That b&d is DEAD WRONG!!!!!!!!!!
Connected originally as it was 6v pos ground , I got a neg polarity spark as expected & set gap screw to maximum that it would arc. Then, reversed battery connections on tractor & repeated and spark now has pos polarity and maximum gap setting that it will arc across is still same. So, same voltage just reversed polarity!!! Next, I reversed the two primary wires on coil & repeated and now I once again have a neg spark polarity, but the gap had to be closed inorder to obtain an arc. So, if you want the neg polarity, you have to give up spark voltage in exchange. Thus it is shown!
Circuit analysis had long ago shown this & except for those that haven't performed same, the imperical approach wasn't necessary or worth all the effor to disconnect, reconnect coil & generator (didn't want to re-polarize). Now, IF it is really important to you about those couple hundred volts & neg polarity (that is, you want tnem BOTH), then you can purchase a coil for a tractor that was factory Neg ground & it will have the correct winding sense (primary rel to secondary) to provide BOTH the higher voltage AND correct polarity.
So, what is your escape route now b&d???
You might actually learn something here, unless you are beyond the learning stage.
Click to expand...

I am trying to understand what you did, Question:

1) Can you describe your tester, is there a spark plug in the curcuit or only the two pointy contacts on the variable gap. Also is this test off the tractor or is the tractor running?

2) What lenght is the spark able to jump, point to point on your tester?

3) What is the difference between changing the battery connections versus changing the connections at the coil - why are the results different?

I am not taking an issue with the test, just trying to understand and maybe learn something.

Thanks Ken
 
You must log in or register to reply here.

Similar threads

Crazy Horse
6V to 12V "step up" auto voltage converter ....
Replies
10
Views
770
BarnyardEngineering
BarnyardEngineering
J
JMOR, A resistor question.
2
Replies
35
Views
1K
JMOR
J
D
Need for ballast Resistor in 12V conversion
Replies
11
Views
822
Pete in Holland MI
P
C
weak spark on a ford 4000 forklift
Replies
4
Views
349
Charlie M
C
C
RTU 12 volt conversion
Replies
5
Views
232
wore out
wore out
Tractor Parts Tractor Manuals

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Copyright © 1997-2024 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters
Website Accessibility Policy

Back
Top