6V ignition coil

[deac]

I want to replace the in my 1940 Buick super with electronic ignition. How do I choose the correct coil? I understand the workings of a coil but I don't know how to choose the appropriate one for the car. I think Cars sells a replacement coil that is 1.5ohm's and produces 55000 volts. Is that appropriate for an electronic ignition? Are those the spec's I should looks at my local parts 

[edinmass]

Hello…….dont want to get into a diatribe about converting it. Don’t bother…….I can give you a bunch of reasons. There is NO ADVANTAGE whatsoever with the conversion. And you're much more likely to have problems. It’s a solution that’s looking for a problem that doesn’t exist. GM was the world’s largest corporation and certainly the best engineering company on the planet in 1940. Billions of miles have been en driven on Delco distributors with no issues. Can’t say the same for the conversions. 

Edited January 29 by edinmass (see edit history)

[Morgan Wright]

If it ain't broke, fix it 'till it is.

[deac]

I guess I didn't make my intentions clear. 

I want to replace my coil in my 1940 Buick Super that's previously converted to electronic ignition and I want to know which one to ask for at the local parts store.

 

Edited January 29 by deac (see edit history)

[Mark Shaw]

I believe you can use the original coil.

[deac]

9 hours ago, Mark Shaw said:

 

 

14 hours ago, edinmass said:

Hello…….dont want to get into a diatribe about converting it. Don’t bother…….I can give you a bunch of reasons. There is NO ADVANTAGE whatsoever with the conversion. And you're much more likely to have problems. It’s a solution that’s looking for a problem that doesn’t exist. GM was the world’s largest corporation and certainly the best engineering company on the planet in 1940. Billions of miles have been en driven on Delco distributors with no issues. Can’t say the same for the conversions. 

Ed, I really value your opinions and knowledge.  Respectfully I would ask you to re-read my initial post.  The ignition system has already be converted by a previous owner and works fine.  I simply want to know how to ask a parts counter person, who is not a Buick guy, for the appropriate coil.

Edited January 29 by deac (see edit history)

[ply33]

2 hours ago, deac said:

 

Ed, I really value your opinions and knowledge.  Respectfully I would as you to re-read my initial post.  The ignition system has already be converted by a previous owner and works fine.  I simply want to know how to ask a parts counter person, who is not a Buick guy, for the appropriate coil.

For my old car, which is basically stock, I have built up a cross reference database with as many modern part number equivalents as I know about. If/when I need to get a part at the local auto supply store I can call ahead and ask for what I need by using their specific part number. Since my car is way too old to be in their computer that is about the only way to go for things like ignition parts, bearings, seals, etc. which are still available if you know what to ask for.

 

For a car that has been modified, I imagine the same technique would work but that database would be car specific. In the highly unlikely event that I'd buy a modified car I would look to the previous owner to give me all the documentation on all the modifications. If they can't provide that information it would be even less likely that I'd consider buying the car.

 

In your specific case, you might want to take your existing coil to your local better auto supply store and see if they can match it up. Once you have that match, record the manufacturer and part number.

[Bloo]

On 1/28/2024 at 3:08 PM, deac said:

I want to replace the in my 1940 Buick super with electronic ignition. How do I choose the correct coil? I understand the workings of a coil but I don't know how to choose the appropriate one for the car. I think Cars sells a replacement coil that is 1.5ohm's and produces 55000 volts. Is that appropriate for an electronic ignition? Are those the spec's I should looks at my local parts 

Nothing is ever easy, is it? The short answer is almost anything that will physically fit. 1940 Buick? Doesn't that have an Electrolock armored ignition? If so the answer is really easy, nothing has been made for decades that fits that. NOS and NORS aftermarket from Ebay and NOS Buick parts dealers. Many online vendors advertise coils for Electrolock equipped cars that will work electrically but not fit the Electrolock. They rarely point that detail out.

 

The voltage spec is pretty much meaningless. It is the maximum the coil can produce, and has no bearing at all on what voltage the spark will run at. It is a spec that comes mostly from marketing people who want to advertise a big number. A higher voltage coil is no advantage, and might be a disadvantage if you want to split hairs because it is probably going to have shorter spark duration. Enough to matter? I doubt it. Any coil you can lay your hands on is going to have enough voltage available for a 40 Buick.

 

The 1.5 ohms (or whatever) matters, but doesn't really tell you much about the coil. That resistance directly affects the current through the points, or through the transistor that replaced them, so it does matter. To that end, you wouldn't really want it to be any lower that whatever the maker of the electronic ignition wants. Lower resistance raises the current.

 

In practice most American coils are about the same resistance, about 1.2-1.5 ohms if memory serves. This is because most 6V coils, 40s and later for sure, expect to be running on a 7.5 volt-while-charging electrical system. Most 12V coils expect to be running on about 7.5 or 8 volts on a 14+ volt system, after the voltage is dropped by a ballast resistor. There are coils meant to run on a 12 volt system directly. Typically they have about double the resistance of the normal ones. You probably don't want one of those, unless the car has been 12 volt converted, and in that case maybe you do.

 

Edited February 1 by Bloo (see edit history)

[Lee H]

6 hours ago, deac said:

I want to replace my coil in my 1940 Buick Super that's previously converted to electronic ignition and I want to know which one to ask for at the local parts store

You’ll need to know the manufacturer and model of the points replacement, because it will be designed to handle a coil of a certain minimum resistance, and therefore current flow. Some need 1.5 ohms (and maybe more), where something like the Pertronix III can handle a coil as low as 0.32 ohms, and no ballast resistor. Those can produce a very hot spark.

[alsancle]

We have lots of threads on this. I myself have made this mistake 20 years ago. And I regret it. It is a horrible, horrible idea.

[Ben Bruce aka First Born]

On which coil to use??   Why?

 

  Ben

[edinmass]

For plain non descript coils, I use Brillman. 

 

Very reasonable, and multiple options.

 

 

https://brillman.com/?gad_source=1&gclid=CjwKCAiAtt2tBhBDEiwALZuhAJydHNCxb080Ud1pCLcI9tcwErBgv1j-HUmhuxAS8svdV2K33pMtdhoCkt0QAvD_BwE

Edited January 29 by edinmass (see edit history)

[deac]

1 hour ago, edinmass said:

For plain non descript coils, I use Brillman. 

 

Very reasonable, and multiple options.

 

 

https://brillman.com/?gad_source=1&gclid=CjwKCAiAtt2tBhBDEiwALZuhAJydHNCxb080Ud1pCLcI9tcwErBgv1j-HUmhuxAS8svdV2K33pMtdhoCkt0QAvD_BwE

I appreciate the referral. Thanks Ed.

 

Chris

 

[deac]

7 hours ago, Bloo said:

Nothing is ever easy, is it? The short answer is almost anything that will physically fit. 1940 Buick? Doesn't that have an Electrolock armored ignition? If so the answer is really easy, nothing has been made for decades that fits that. NOS and NORS aftermarket from Ebay and NOS Buick parts dealers. Many online vendors advertise coils for Electrolock equipped cars that will work electrically but not fit the Electrolock. They rarely point that detail out.

 

The voltage spec is pretty much meaningless. It is the maximum the coil can produce, and has no bearing at all on what voltage the spark will run at. It is a spec that comes mostly from marketing people who want to advertise a big number. A higher voltage coil is no advantage, and might be a disadvantage if you want to split hairs because it is probably going to have shorter spark duration. Enough to matter? I doubt it. Any coil you can lay your hands on is going to have enough voltage available for a 40 Buick.

 

The 1.5 ohms (or whatever) matters, but doesn't really tell you much about the coil. That resistance directly affects the current through the points, or through the transistor that replaced them, so it does matter. To that end, you wouldn't really want it to be any lower that whatever the maker of the electronic ignition wants. Lower resistance raises the current.

 

In practice most American coils are about the same resistance, about 1.2-1.5 ohms if memory serves. This is because most 6V coils, 40s and later for sure, expect to be running on a 7.5 volt-while-charging electrical system. Most 12V coils expect to be running on about 7.5 or 8 volts on a 14+ volt system, after the voltage is dropped by a ballast resistor. There are coils meant to run on a 12 system directly. Typically they have about double the resistance of the normal ones. You probably don't want one of those, unless the car has been 12 volt converted, and in that case maybe you do.

 

Thanks Boo,

Your information is always helpful and insightful on whatever topic I manage to bring up. Now I have a basis for what I am looking for.....

 

As always your input is much appreciated,

Chris

[Ben Bruce aka First Born]

Chris, you cannot go wrong listening to Bloo.

 I switched/converted myb1950 years ago. I initially used a pertronix unit and used their coil.

 

  Ben