Tale of two,Positive Grnd

[Two0aks]

I've searched posts with many contributors such as JMOR and souNdguy and others and I'm looking for additional verification pertaining to the NAA 6V Pos ground.

Owned for 30 Yrs a Fergy TO30 6V Pos Grnd, and coil terms have a + and - . The + goes to the Distributor. Runs great always has.

Also a 53 NAA Jubilee 6V Pos ground and the Coil that came with it and reinstalled had [b:2539f89cc1]Bat[/b:2539f89cc1], and [b:2539f89cc1]Dist[/b:2539f89cc1] stamped on it. Coil only fits one way with dimple located to hole in bracket. Terminals are on Block side of coil.

I believe (from a bad picture I took 12 years ago) that the terminal marked [b:2539f89cc1]Batt[/b:2539f89cc1] goes to the Distrubutor.


Strangely though, Dennis Carpenter sells what he calls OEM Coils 8BA-12029 that have the Bat and Dist stamps on them. Anyway I don't know what Original Coils looked like and just want to get polarity correct. 6V Positive ground went all the way to 1964.

If you have knowledge of this topic, thanks for adding to the already much discussed issue. And I do not have a O-Scope.

Bill

 

[JMOR]

(quoted from post at 15:26:23 08/24/23) I've searched posts with many contributors such as JMOR and souNdguy and others and I'm looking for additional verification pertaining to the NAA 6V Pos ground.

Owned for 30 Yrs a Fergy TO30 6V Pos Grnd, and coil terms have a + and - . The + goes to the Distributor. Runs great always has.

Also a 53 NAA Jubilee 6V Pos ground and the Coil that came with it and reinstalled had [b:9e18d603b3]Bat[/b:9e18d603b3], and [b:9e18d603b3]Dist[/b:9e18d603b3] stamped on it. Coil only fits one way with dimple located to hole in bracket. Terminals are on Block side of coil.

I believe (from a bad picture I took 12 years ago) that the terminal marked [b:9e18d603b3]Batt[/b:9e18d603b3] goes to the Distrubutor.


Strangely though, Dennis Carpenter sells what he calls OEM Coils 8BA-12029 that have the Bat and Dist stamps on them. Anyway I don't know what Original Coils looked like and just want to get polarity correct. 6V Positive ground went all the way to 1964.

If you have knowledge of this topic, thanks for adding to the already much discussed issue. And I do not have a O-Scope.

Bill

"Finally, dont let anyone tell you it dont matter which polarity you wire a coil, its true she will still spark if wired bass ackwards, but its more efficient if wired at the correct polarity. If its a Neg ground tractor, + (Battery) on coil wires to switched ignition circuit (or ballast if used) while - (dist) wires to the distributor. Reverse that for Pos ground. "
That's right.......don't let anyone tell you anything unless they can fully explain why. And just connecting + to + and - to - is not going to guarantee you maximum voltage, even though it will yield a negative HV spark, Sir! It depends on the particular coil. If the coil was designed for a Positive ground system & you change it to a Negative ground system & leave coil wired as it was from factory, you get full voltage out, but a Pos polarity spark. Swap the coil wiring & you get your Negative spark, BUT at a lesser voltage, by the amount of voltage across the primary during the spark (typically 100:1 ratio). You can NOT have both neg spark & full voltage UNLESS you swap to a coil with a different winding sense/connection of primary & secondary, as in a coil designed for a Negative ground system. + to
+ and - to - alone will not cut it. This technology is 100 years old & still the information floating around is "what I've always understood/heard" instead of real hard fact. It is just amazing!
Another aspect that really kills the spark polarity aspect is that both the center & side electrodes are cold at start up, just when you need a hot spark the very most.
Further more, your old magneto tractors have every other spark output alternating +/- in polarity, as did all the old HD motorcycles, and many 'wasted spark' modern engines.........so just forget spark polarity, once & for all!!!
BUT, ....if you really insist on neg spark polarity, it is as simple as watching the direction of "scatter" off the pencil lead.

 

[Jim L WA]

Great write-up JMOR. I never knew that, but then I'm not 100 years old yet

 

[JMOR]

(quoted from post at 16:44:29 08/24/23)
Great write-up JMOR. I never knew that, but then I'm not 100 years old yet

Thank you. I'm too close.

 

[Fritz Maurer]

In other words, the same spark plugs are firing
backwards every time?

 

[Mike(NEOhio)]

Somebody please correct me if I'm wrong on this but I recall that the internal connections are different in coils for positive and negative ground
systems. Not just going by the + and - terminals. Primary and secondary windings are connected to one or the other. They will still spark but not
as strong.

 

[JMOR]

(quoted from post at 21:00:23 08/26/23) Somebody please correct me if I'm wrong on this but I recall that the internal connections are different in coils for positive and negative ground
systems. Not just going by the + and - terminals. Primary and secondary windings are connected to one or the other. They will still spark but not
as strong.

es, that is explained in my post earlier in this thread.