Drive train conversion

[jgreg53]

Can a p15 be modernized with a modern engine and transmission and remain 6 volt?

[Slickster]

Sure, unless you are considering fuel injection, but why stay 6v?  if you take on major renovations, going 12v will be just a bump in the road...

[Los_Control]

11 minutes ago, jgreg53 said:

Can a p15 be modernized with a modern engine and transmission and remain 6 volt?

I do not think so ... but why would you?

1rst issue is the starter .... you can use a 6 volt starter on a 12 volt battery charging system.

I do not think you can use a 12 volt starter on a 6 volt battery.

Any modern engine will have a 12 volt starter.

[Los_Control]

you can switch to 12 volt, then run a voltage reducer to certain items like radio or heater motor windshield wipers

[knuckleharley]

Yes,depending on how you define "modern engine". Computer engines are out.

 

The question is WHY in the world would you even want to do this? Switch to 12 volts when you switch engines.

[Andydodge]

As others have said.....Yes but Why?........once you install a "modern" engine & trans the extra effort to stay 6 volts is hard to understand......how "modern" do you want to go? as this will define how simple or complex this idea is.........the US auto industry went 12 volts from 1955(?) onwards..........andyd     

[Sniper]

Well, if he was to stuff an early hemi in there and make it look period then it'll be a 6v setup anyway.

 

Depends on what he's thinking.

 

If he wants an LS in there, well I suppose a good old school automotive electrical shop might be able to redo the starter to run on 6v, I know they can go the other way.

[Dan Hiebert]

I'll venture out on a limb here...it depends.  If you mean the whole car, then no.  All the systems that make a "modern" engine run are engineered to work on a 12v system.  You can conceivably rework some things to work on 6v, but I don't think it would ever run very well if you did that, because it is supposed to start and run on 12v.  As noted, you can have the engine itself working on 12v, and reduce the voltage for everything else.  If you convert the whole car to 12v, there may still be a component or two that may need a reducer because there isn't a direct conversion to 12v available.  Personally, if I were to convert a 6v car to a modern engine/transmission, I would convert the whole car to 12v.   I don't think it's impossible, just very impractical.      

[Plymouthy Adams]

as many here have stated, its is doable but why....you are going to run into enough difficulties making an engine upgrade as it is, why make it harder for yourself and further increase the cost by trying to maintain an older system that is outdated, low availability and supported mainly from specialty shops, much less shoot yourself in the foot and not be able to go into a big box store for replacement parts and risk stranded or towed home due to no parts across the counter and solely mail order.  I will not say you should go either way....as it is your choice...but I do suggest you weigh your options and study the expected results a bit closer.

[Sniper]

Since no one knows that the OP is thinking when talking about a modern engine and transmission no one can say it's a good or a bad idea.

 

a 318 and 904 out of an 80's Mopar would be modern in comparison and minimal issues on 6 or 12v, other than the starter.

 

a fuel injected engine with an electronically controlled transmission, no not going to work on 6v. 

[Los_Control]

Only reason why I plan to stay 6 volt is because am a cheap arse .... when I need to start replacing generator etc .... going 12 volt.

[Tooljunkie]

Ever price out a 6 volt starter? Im in canada, but you will get the idea. New starter for my 51 fargo, $238.00

compact high torque starter for  a 318, i can get a new one for $100.

generator vs alternator? Depends what you prefer. 
 

but a running 318/904 complete in a donor car can vary from a couple hundred and up. 
if i was doing a swap, donor car all the way. 

[jgreg53]

I get what you guys are saying, but rewiring the whole car sounds like a huge undertaking. I've never been that profficent at electrical.

[jgreg53]

So an early hemi (if i could even find one), it would be 6 volt already?

[kencombs]

1 hour ago, jgreg53 said:

So an early hemi (if i could even find one), it would be 6 volt already?

Yep, but the price of every engine part goes way up when dealing with hemis.

As to rewiring,  yes it can be a challenge.  On the other hand, if your old wiring is serviceable,there is no need for a total rewire just to change voltage.  6V chassis wiring is always a larger gauge than needed for 12v lights, charging circuit etc.

[Los_Control]

13 hours ago, jgreg53 said:

I get what you guys are saying, but rewiring the whole car sounds like a huge undertaking. I've never been that profficent at electrical.

You wont need to worry about wire size when switching to 12 volt. With 6 volt the wire is larger then a 12 volt system. What you have will be fine without changing the wiring if you convert to 12 volt.

This is why we can convert to 12 volts and keep the 6 volt starter, it is built heavier then a 12 volt starter.

Back in the 1970's, when these were just 20 year old beaters to drive around. People would convert to 12 volt because it was cheaper and easier then buying expensive 6 volt battery.

 

Assuming what you have is in good condition. Usually by now your wiring is falling apart, either been replaced already or needs replaced .... or the car has been well stored and original wiring in good condition.

[jgreg53]

I've always said if and when my original motor dies then i would do the upgrade, but the damn thing just keeps running.

[jgreg53]

I might add, everything electrical works. Gauges accesories lights horn heater. So i guess my wiring is ok. So i could use some of the wiring can be saved if changing to 12 volt. By the way, i have a 6 volt pos ground altenator.

[Sniper]

I rewired my 51 when I got it, took me a solid weekend, but electrical/electronic stuff isn't an issue for me.  Been doing it since 84.

[jgreg53]

When changing to 12 volts, all light bulbs need to be changed?

[TodFitch]

30 minutes ago, jgreg53 said:

When changing to 12 volts, all light bulbs need to be changed?

 

There may be some LED lamps that can handle both 6v and 12v (LEDs are actually about 3v and there is electronics in the bulb to regulate things down and it depends on how that voltage regulation was implemented).

 

But incandescent, quartz-halogen and lamps in general are designed for a specific voltage and 6v bulbs will be blow out nearly instantly in a 12v system. And 12v bulbs will be very dim in a 6v system. So yes, if you change to 12v you need to change all the light bulbs.

[mlozier76]

Just remember, if putting in a more modern engine (anything with more horsepower) you should take a look at brakes, shocks and other items. Wiring has been problematic on my 48, but is to be expected.  I've changed or rewired several harnesses now and the car tends to run much better as a result.  Phantom draws definitely affect electrical performance.