6 volt ignition coil for 1932 Packard

[scott12180]

Does anyone have a recommendation for an appropriate 6 volt ignition coil for a 1930's Eight cylinder Packard?

 

I recall reading somewhere that you do not want to use the "Flame Thrower" coils with an old-style point-and-condenser system as these coils require an electronic ignition system to operate properly.  Any thoughts on that?

 

But basically I think that any six volt coil should be fine for a 1930's car.  My gut says to avoid the super-high voltage coils since my ignition wires are stuffed into a metal conduit and there's a possibility for arc-ing inside.

 

-- Luke

[edinmass]

You can use any coil, the high  KV’s on the secondary ignition wires will not arc or jump if you have a good cap, rotor, wires, and plugs, with a correct gap. With today’s modern fuels, you should run a hotter plug, and jet the carb for E10 if that’s what you are running. If your engine is new and built well, you can also add timing in the advance plate. We run a 904 with all stock components with no issues. 

Edited November 30, 2018 by edinmass (see edit history)

[PFitz]

Scott,

The high Voltage coils are not recommended for tube wire looms because the high voltage can cause inductive cross firing. That's when a high voltage pulse travels through one wire and causes a strong magnetic field that induces a current to flow in wires that are close and parallel to the high voltage pulsed wire. It's the same voltage caused magnetic field principal that makes transformers work.

 

You can see evidence of inductive cross firing by hooking up a timing light  to each spark plug wire, in turn, and see if it shows any doubled flashes, instead of only single, evenly spaced flashes.

 

The standard 6 volt coils you can buy through autoparts stores are a bit higher voltage than any of the good originals I've been able to test. But, they rarely cause inductive cross firing. High voltage coils used with wire looms is asking for a rough running engine caused by extra sparks at the wrong time in a cylinder cycles.  

 

Paul 

 

 

Edited December 1, 2018 by PFitz (see edit history)

[Otahuhu]

Are there any issues using a flamethrower coil with an external ballast on a points distributor ? 

[PFitz]

I've never used a flamethrower coil, but if your still talking 6 volt coils like the OP, they have  built-in resistance, so they don't need an external ballast resister like a 12 volt coil does. 

 

Paul

[Pfeil]

2 hours ago, scott12180 said:

Does anyone have a recommendation for an appropriate 6 volt ignition coil for a 1930's Eight cylinder Packard?

 

I recall reading somewhere that you do not want to use the "Flame Thrower" coils with an old-style point-and-condenser system as these coils require an electronic ignition system to operate properly.  Any thoughts on that?

 

But basically I think that any six volt coil should be fine for a 1930's car.  My gut says to avoid the super-high voltage coils since my ignition wires are stuffed into a metal conduit and there's a possibility for arc-ing inside.

 

-- Luke

It really doesn't matter if you have a "super high voltage coil" or not. The coil only throws out the amount necessary to jump the gap of the spark plug in the combustion chamber. A stock 6V coil can produce as much as 30KV but in normal operation it only takes 8-10 KV to fire off a spark plug in a normal engine, under load a little more. If you have bad wires a stock coil output will find it's ground anyway. Many manufacturers had those tubes and they all went away. The problem with them is twofold : a cracked wire will arc to the tube and short that cylinder, also when two or more wires are close together there can be induction from one wire to another and this is why these wire holders were invented to keep the wires separate. I have two cars with BOSCH 6 volt coils that have been in use for over fifty years with no problems and will still test up to 30KV. If you have to use tubes use the best wires possible.

 

 

 

 

[edinmass]

I recently tested a flame thrower coil, a NAPA coil, and a Standard Ignition coil on my  1940’s new to me Herbrand Coil Tester.(See YouTube video of tester.) All three tested the same........the Flame Thrower was new out of the box, the Napa was also new, the Standard was forty years old with ten thousand miles on it over the years. My Pierce 12 has wire looms four feet long on each side, and there are no issues, and I just went through a V-16 Cadillac ignition with 18 wires coming out of the cap, again, no issues. As long as your wires arn’t Thirty or forty years old, you will be fine. PS- watch the video, it’s neat.

 

 

Edited December 1, 2018 by edinmass (see edit history)

[Curti]

If there is no ballast resistor built into the coil, what is the difference between a 6V & 12V coil?  I have new coils that are not marked.

[Pfeil]

14 hours ago, edinmass said:

I recently tested a flame thrower coil, a NAPA coil, and a Standard Ignition coil on my  1940’s new to me Herbrand Coil Tester.(See YouTube video of tester.) All three tested the same........the Flame Thrower was new out of the box, the Napa was also new, the Standard was forty years old with ten thousand miles on it over the years. My Pierce 12 has wire looms four feet long on each side, and there are no issues, and I just went through a V-16 Cadillac ignition with 18 wires coming out of the cap, again, no issues. As long as your wires arn’t Thirty or forty years old, you will be fine. PS- watch the video, it’s neat.

 

 

I'm curious to know the results of your test. What was the maximum KV per each coil in the test?

[scott12180]

Thanks, guys,  for your advice on the coil.

Youv'e made me realize that the ignition wires are at least 40 years old, and yes they are stuffed into in a metal conduit or loom.  It's not too much of a stretch to imagine that I could very well be getting some arcing in there.

 

And since I've no idea of the history of the coil, I'm going to get a new coil and ignition wire as well.  At least I can eliminate that source of trouble.

 

-- Luke

[TerryB]

9 hours ago, Curti said:

If there is no ballast resistor built into the coil, what is the difference between a 6V & 12V coil?  I have new coils that are not marked.

It would have to be the DC resistance of the coil.  Most coils will draw from 3 to 6 amps when the points are closed and the engine is not running (current drops when the engine is running).  At 6v it will take a DC resistance of 1 to 2 ohms in the coil to get that level of current to flow.  If you connect 12v to that same coil without a ballast resistor you will draw between 6 to 12 amps which will overheat the coil and probably wreck the point contacts.  The ballast resistor acts to increase the resistance in the primary coil circuit to get the current flow back to the more desirable 3 to 6 amp level. 

[TerryB]

And to simplify, the 6v coils are usually in the range of 1.5 to 2 ohms and the 12v coils that don’t require a resistor are in the 3 to 4 ohm range.  A 6v coil can be made to work in a 12v circuit by adding a ballast resistor in series with the coil.  The ballast resistor should be about equal to the resistance of the 6v coil.

[Curti]

Thanks Terry !  Electrics are not my strong suit. I have new and used coils that are not marked 6 or 12 V ,  they must work in either application. 

 

[John_Mereness]

I usually go to the auto parts store and ask for a coil for a 1951, 1952, 1953, 1954 Chevrolet (usually in their books) and they pull a 6 volt Standard brand off the shelf (or something comparable). And, the same goes for condensers.   In 1955 Chevrolet went to 12 volts.