6v to 12v?

[kmac530]

I have always been an advocate of 12v. Brighter lights, easy to jump start in time of need, many batt chargers are only 12v now, voltage regulators and starter solenoids are readily available at any AP store, and a number of other reasons. I am not building a OE truck or concours show truck, just an old daily driver that is already quite modified, v8 and OD trans...

I plan on re-wiring the truck before it hits the road, but before all of that I want to make sure that the motor runs well enough to bother using it.

On previous car builds I have done where I converted to 12v {many VW bugs} we left the 6v starter. I never had an issue with it ruining it too quickly, eventually but not right away.

My question is on an idea I have that needs your input. I was thinking about disconnecting ALL wiring from the motor, then using a 12v battery, basically hot wire the motor direct to the coil just to fire the motor up.

I know to drive the car for long I would need to change the condensors and probably the ballast resistor {if it has one-I think I saw one} and possibly coil and points and maybe a few other bits.

BUT, do you folks see any reason I could not just leave the old 6v coil, points, condensors, and balast resistor just to fire it up?

I have heard that coils will work 6 or 12v {maybe not forever or the most efficiently} and points are just a breaker that should work, again at least for a while, my concern is the ballast resistor and condensors.

I plan on going to a pertronics electronic igntion once I get it on the road, but I dont want to spend the money on that if I need to change motors since I may not use a Stude motor if I have to do an engine swap.

I just want to fire it up to see if the engine is sound and does not have a busted rod internally or some other catastrofic issue.

Will it run on a 12v set up? I dont want to buy a 6v battery just to fire it up diagnostically?

[whacker]

If you put a ballast resistor on the coil, it should be fine. Rewire the coil backwards, as 12V is negative ground and 6V is positive ground.

[gordr]

Sure, it will work. I have done the same thing many times. Be sure to observe polarity; six volt Studebakers were positive ground, and so should be your 12 volt battery, unless the coil has been changed at some point in the truck's career. The starter will spin the right way regardless of polarity.

Be sure to apply power to the coil only while cranking or while the engine is actually running. A six volt-volt coil will quickly burn out if connected to a 12-volt source with the engine stationary and the points closed. Or else the points will burn, sooner. They would burn eventually, anyway, seeing as they switching about twice their designed current, but they should hold out long enough for you to hear the engine run and evaluate its condition.

[kmac530]

That is exactly the kind of info I needed. I thought it could be done easily, but info on the + ground and flipping coil wires...perfect. Thanx.

Any other info that may be pertanent is appreciated.