Running a flathead on 12 volts

[Mike B]

I'm not looking at doing a conversion to 12 volts, but here's my deal...

I have 221 I want to fire up I have it wired up and turning over just fine, now I'd like to see about spark/etc and if she'll run okay.

I just have 12volt batteries here....the wiring is missing the ballast resistor, can I just use a GM or Chrysler Ballast resistor (because I have a few laying around)?

Will running 12v through the GM or Chrysler resistor protect the points/coil well enough?

Thanks.

[Henry/Kokomo]

Mike -

You don't mention if you're using the original coil or not. What you're looking for is about 4 volts to a 6 volt coil. If you have a 12 volt coil, you need about 9 volts to the coil, maybe less. The brand of the resistor doesn't matter. The ohm value of the resistor does matter. The resistor should be wired in series with the primary winding of the coil. Depending on how your distributor is arranged, maybe you could hook up a 12v coil just to start the engine? You need a volt meter to check out the specific voltages. Hope this helps. Good luck.

[Mike B]

Thanks Henry,

It's a Lucas distrubutor, has two caps on either side (not sure what it's refered to as) and a coil bolted on top of it. I'll pull the coil off and see what;s involved in running a newer coil...I've a few extra cannister types around somewhere.

Might have to see how many resistors I can round up to drop enough voltage as well.

Thanks

[19-c]

Some traditionalists might not agree but The Mallory 12v electronic ignition for the flatheads is a great upgrade. great spark, very reliable, and no messin with the original points As long as you're switching to 12 volt its a nice upgrade to the flattie. good luck any way you go.

[Mike B]

Right now I just want to get it fired up....it's just the engine/tranny sitting in the chassis...it'll be awhile before I want to make any upgrades.

Just waiting for the wife to get home to watch my granddaughter so I can go out and start scrounging some parts!

[flatjack9]

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It won't hurt it to run 12 volts for a short period of time. There is an adapter that is made to allow you to use a modern coil. Most old Ford suppliers will have it.

[Mike in AZ]

they sell a remote coil setup for your distributor....then maybe with a 12V coil??....Mike

[Jason in TX]

Use one of those ceramic chrysler resisters in line with the coil wire.

In fact, I JUST went to the garage and fired up my 1940 flathead with a 12V battery before reading this.

Here is a link to the video!
https://www.youtube.com/watch?v=ilkmn_GXRbo

[Mike B]

Thanks guys!

Tried a quick test to see if I had spark...nothing, so will pull the caps in the morning and check the point gaps...

BTW, is the condenser 6 volt specific, or are condenser "bi-voltage"?

Thanks!

[Bill Steiner]

Does not make any diff. on condenser. Bill