Technical Converting a 6 volt System to 12

I planning to convert my 49 Merc flat head to a 12 volt alternator with negative ground and Petronic solid state pointless distributor system. All the cab wiring will be new so no problem there but what considerations/adjustments do I need to make to the stock 6 volt coil, starter, overdrive solenoid and any other ignition or power train components?
Thanks

 

Ignition could use a ballast resistor in the power line to coil. Starter no issue, though the Bendix will eventually straighten. Overdrive solenoid might be fine. Ballast resistor to heater blower will sort that. Dash light bulbs can stay 6v, if dimmer turned way down.

Cosmo

 

What happens when the "Bendix" straightens? I was wondering If I can knock down the voltage going to the starter and the overdrive solenoid ??

 

if dimmer turned down! 12 will blow your 6v lights out in a heartbeat if that dimmer ever moves

 

good to know ..

 

12v OD solenoids are more common than 6v ones. I wouldn't try running a 6v one on 12v, find a 12.

 

change the bulbs out to 12v. They are cheap and the dimmer can then be used.

 

Replace your coil with one that is compatible with the petronix unit. Your starter doesn't need a thing it will work fine. get a 12v solenoid for your OD. Forget about your radio there is nothing on AM anyway.

replace all your lights with 12v lights, makes sure that your grounds are clean while you are at it. if you have turn signals replace the flasher unit with a 12v flasher unit. Probably wouldn't hurt to either replace your blower motor with a 12v motor or get a resister to drop the line voltage to 6V.

That's just the basics there is no doubt t something that you will have to deal with besides that.

 

Someone schooled me on gauges on fords the other day, they said that all Ford gauges were 6v up into the '80s and that you just get the voltage reducer from a later model Ford and put it in line. I haven't checked that out yet but I am going to.

 

This is from my post on my 12V conversion on my 48 F-1. You may find some of this useful:


"This is what I used, it may be helpful for other F1 owners who want to do a 12V conversion:
Napa Echlin Voltage regulator for 1956 F100
Napa Echlin Coil IC14 (this is an internally resisted coil AND it fits in the original coil holder)
3 Runtz diodes
I had actually bought a 12V starter solenoid, but didn't install it. Still using the 6V
And had my generator rewired at a local shop to the tune of $100 out the door.
Oh, and don't for get your bulbs.
1155 for parking lights
#57 for the dash lights
#53 for Hi beam indicator (my indicator stays on full time now, need to figure out why)
1157's for the taillights.
6014s for the headlights if you can find them. Napa gave me a halogen equivalent, which I'm a little leary of with the stock headlight switch. May put in some kind of relay"

 

****** is correct about the Ford gauges. Mopar did this too. There is a voltage regulator on the back of the instrument clusters that give the gauges a constant 5 volts, regardless of battery voltage. This compensates for fluctuating voltage while the system is charging or if the alternator is not putting out the gauges maintain a constant 5 volts. You can build your own with components from digi tech.

See the link to find out how to do it. This one is related to a Dodge but the voltage output is the same. Step 9 tells how to build the voltage regulator for gauges.
http://www.allpar.com/history/mopar/electrical2.html

 

good advice

 

Thanks for the info, that may save me some time under the dash in the wrecking yard.

 

I did one for a friends 67 Dart and also for my 88 Turbo Coupe. The gauges in the Dart hadn't worked in 6 years. He thought because all gauges were not working that he needed a new wiring harness