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Another 12 volt conversion/coil question

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Randy Bagrowski

11-08-2005 11:23:17

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I'm converting my 1952 8N. I'm confused about coils. I understand the need to add a resistor if keeping the 6 volt coil but I'm confused about using a 12 volt coil. From what I understand, to do it it correctly I should measure the resistance of my coil, if it is NOT approximately 3 ohms, then I should add a resistor. Is this being too technical or do most of you just put in a 12 volt coil and call it a day?
Thanks for any input.
Randy B.

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Randay Bagrowski

11-09-2005 03:29:36

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Re: Another 12 volt conversion/coil question in reply to Randy Bagrowski, 11-08-2005 11:23:17

Thanks guys, I'll get me a Napa coil that's a true 12 volt.

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souNdguy

11-08-2005 12:19:14

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Re: Another 12 volt conversion/coil question in reply to Randy Bagrowski, 11-08-2005 11:23:17

Get a napa ic14sb if it is a round coil.. that is a true 12v coil.. no external resistor needed.. no internal resistor either.. the coil primary is simply the correct impeadance due to wire gauge and number of turns.

Soundguy

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old

11-08-2005 11:50:29

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Re: Another 12 volt conversion/coil question in reply to Randy Bagrowski, 11-08-2005 11:23:17

The easy best way is to get a 12volt coil with internal resistor and call it a day.

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Tim...Ok

11-08-2005 12:18:42

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Re: Another 12 volt conversion/coil question in reply to old, 11-08-2005 11:50:29

Is the current limiting resistor not needed when using a 12 volt coil with built in resistor on a sidemount?? All I've dealt with is front mounts,and I know you will burn up the 12 volt coil with out them..

Tim

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old

11-08-2005 12:29:11

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Re: Another 12 volt conversion/coil question in reply to Tim...Ok, 11-08-2005 12:18:42

Well if its a true 12 volt coil no you don't need the ballast resistor, but very few are true 12 volt coils. You need one that says on it no resistor needed or internal resistor. Most of the older Chev coils where true 12 volt coils and I use them when doing a 12 volt switch over.

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souNdguy

11-08-2005 12:27:50

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Re: Another 12 volt conversion/coil question in reply to Tim...Ok, 11-08-2005 12:18:42

True 12v sidemount coils DO NOT need any type of resistor to run on 12v.

12v square coils do need about 1/2 ohm external resistance on 12v.

As I said before.. I think you will be VERY hard pressed to actually find a modern ignition coil with a built in restive element rather than the manufacturer simply adjusting the primary resistance of the coil thru wire gauge and length.

Soundguy

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Jim Cox

11-08-2005 16:53:40

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Re: Another 12 volt conversion/coil question in reply to souNdguy, 11-08-2005 12:27:50

Well said. I hope people will archive this one.

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old

11-08-2005 12:41:09

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Re: Another 12 volt conversion/coil question in reply to souNdguy, 11-08-2005 12:27:50

Sound, either way it goes it comes out to be the same differance. I've seen and do use both types.

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souNdguy

11-08-2005 20:00:42

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Re: Another 12 volt conversion/coil question in reply to old, 11-08-2005 12:41:09

While the resistance does come out to be the same.. why wast half the power in your ignition system by disipating it as heat thru a power resistor.

I realize that any excess high voltage past what is needed to jump the sparkplug is not necescary.. but when you introduce age and corrosion intot he system.. the true 12v coil int he system will have more 'reserve' high voltage capacity than the 6v coil and resistor.. it will be a more robust system.. more fault tolerant.. and we need all we can get with these old machines.

I too used a ballast resistor and 6v coil on my NAA untill it failed. when the coil died one day, I simply replaced it with a real coil and got rid of the balalst resistor. Cost of the 12v repalcement coil was actually cheaper than the 6v coil anyway..

Soundguy

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old

11-08-2005 20:05:51

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Re: Another 12 volt conversion/coil question in reply to souNdguy, 11-08-2005 20:00:42

Sound I think you missed what I was saying. What I was tring to say was theres coils with internal resistors and theres the newer one that are true 12 volt coils with no resistor needed. Both do the same thing and cost about the same. I know the last one I got was a 12 volt coil but they still make the ones with the internal resistor.

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souNdguy

11-08-2005 20:40:51

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Re: Another 12 volt conversion/coil question in reply to old, 11-08-2005 20:05:51

Perhaps for vintage/originality/collector or specialty use.. but I doubt that the common off the shelf 12v coil is anything more than a ball of copper... way cheaper to rate resistance on wire size and length rather than incorporate a resistive element inthe coil design.

Soundguy

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old

11-08-2005 20:51:56

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Re: Another 12 volt conversion/coil question in reply to souNdguy, 11-08-2005 20:40:51

Very true but the last coil I got said right on the side internal resistor, but of course thats not saying it really had one in it. It could have also been saying it had the heavyer, more wire type.

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souNdguy

11-08-2005 21:00:19

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Re: Another 12 volt conversion/coil question in reply to old, 11-08-2005 20:51:56

I'd be inclined to agree with you. many manufacturers do not update their packaging or markings very timely. I caught a napa advertisement and info pic that was nearly 10 years old, and it showed the ic14 coil as NEEDING an external resistor.. I pointed it out to their corporate people and didn't even get a reply.

I think some manufacturers also don't change the wording of 'internal resistor' as people have been used to hearing that since the 70's.

So yes.. I agree with you.

Soundguy

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old

11-08-2005 21:08:12

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Re: Another 12 volt conversion/coil question in reply to souNdguy, 11-08-2005 21:00:19

And whats bad is most parts stores have kid behind the counter that don't even understand how an engine works let alone what parts there are under the hood. Shoot most don't even know to check the oil in there own cars. LOL

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souNdguy

11-08-2005 21:12:42

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Re: Another 12 volt conversion/coil question in reply to old, 11-08-2005 21:08:12

Most parts counterpersons scare me. our local NH dealer has a kid at the computer.. I have to tell him what 8n parts that NH still services when i go in for parts, as he will always say no longer serviced.. if I don't have the part number with me.. etc.

Soundguy

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old

11-09-2005 08:12:50

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Re: Another 12 volt conversion/coil question in reply to souNdguy, 11-08-2005 21:12:42

Yep I've had times when I had to show the kids the books that list the parts. Now days if it not in the computer they think it isn't something they can get. Guess they didn't teach them what books are or for the matter how to read. LOL

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