Voltage quandry... need advice...

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Magnum

Well-known member
Joined
Aug 13, 2012
Messages
111
Location
southern MN
so 1st off, this is not really a "rat" more like a survivor, which I'd like to keep "looking" as original as practical...

the car... 1938 Nash Lafayette trunk back sedan... ( I bought the car with 36,000 original miles )

since the car is so low, & I don't have a lift, & a previous owner had used the lighter gage 12 volt battery cables, the gauges are all electric, rather than mechanical, I put an 8 volt battery in the car when I bought it... I'm really happy with how it starts, & had considered converting it to 12 Volt, as I added 12 volt bulbs to the headlights & tail lights, to make them last longer with the 8 volt battery, but this isn't easy, as on the Nash, as the water pump is slave driven, off the back of the Generator...

I trashed out my 8 volt battery, from not checking the water level often enough ( like never in 2.5 years.... I know... dumb ass, but the battery is under the seat, & I just never got under there ) & this car has an old "cut out" rather than a vintage voltage regulator, so it's hard on the water level...

so... my options...

any option is going to require removing the core of the alternator, & extending the shaft out the back side to drive the water pump...

Powergen alternators look just like a generator, but hold the guts of a modern alternator, they are available in 6 volt positive ground ( my original specifications ), or 12 volt negative ground, if I wanted to switch things over... only thing with the powergens, is they are really expensive to buy, & I'd still have a couple $100.00 in modifications...

I see I can buy a modern 8 volt alternator, as an option...

I can't imagine that I couldn't fabricate an alternator cover, that would make a common alternator look like a generator on the outside...

a few other complications ( or considerations ) is my fuel sender is bad... I'm sure there is not an 8 volt sender, finding a new / good 6 volt sender is probably harder than finding a new 12 volt unit... so I guess I'm willing to part with new 8 volt battery, that I put in for short term use, even though it works great in the car, in favor of either the 6 volt or 12 volt for long term use...

I bought a vintage & refurbished 6 volt positive ground AM / FM radio from Europe to mount in the glove box of car originally, as well as a NOS dash clock, so if I went back to 6 volt, I could install those...if I went to 12 volt, there are any number of Stereo's that could go in ( Secret Audio & such, that could mount elsewhere for a fraction of the cost, & give me my glove box back...

I plan on keeping the car pretty much long term, so I don't mind putting a more expensive fix to it, so long as I don't change my mind again next year...

looking for advice & or suggestions... thanks

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That car is really cool. Here's what I'd consider doing if it were mine - go with a 12V battery (you already have the lights changed plus it gives you more options), get an H/O internal regulated altnator, and get separate water pump drive motor to run the water pump.
 
thank you... I want to permanently keep the original engine, & Nash has some really quirky stuff that people like to look at, at the shows ( no intake or exhaust manifolds, they're built into the head, & the carb & exhaust bolt directly to the head, & the slave driven water pump ) I'm not afraid to go outside the box on some things... my bumpers are custom, but still "look" period... I was having water pump issues with the packings, & grease zirk, so last year I had my machinist buddy mill out the insides to take modern sealed bearings, now the pump still looks original, but no longer needs grease pumped into the packings... ( I was having cooling issues, & boiled out the radiator, the service guy, said 5-10 lbs of packing fibers & grease came out of the veins... this is why I wanted to "modernize" the insides of the pump )

the same machinist buddy can easily extend the shaft out the back of an alternator or generator look a like...
 
Why not keep the stuff under the hood, and use one of those kits to put a 12 volt alternator under the car and drive it off of the driveshaft? On second thought, it probably has a closed drive line, so that won't work......
 
Not being able to see the issue with the water pump

and not having rooted around under the dash of a 38 Nash...this is a crap shoot but if you converted to 12 volt can you use an alternator with a dual belt pulley to drive the pump?? I have used a serpentine belt alt on a v belt drive by simply swapping pulleys off an older v belt alt......but I don't know how the set up looks now so as I said just a guess......and yes a cool ride...
 
On 12v that 6v starter won 't last long. Just something else to consider, also going from pos ground to neg ground the starter won 't work, either.
 
thanks for the positive comments & reply's guys... I'm still open for suggestions... I want to spend whatever I have to only once, so I want to be happy permanently, with whatever I decide...

I haven't taken a picture of this side of the motor, since I rebuilt ( re-machined ) the water pump, added a red coupler & stainless coupler hardware( BTW, she's also currently wearing a set of new red & black cloth wrapped ignition wires )... but this is a pic of the set up, as it was the day I bought it a couple years ago... the old tyme "cut out" switch is the lil box sitting on the generator... works good, but is hard on battery water :eek:

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& one more of the other side, to show some of the quirky Nash features ( when I take it to a show, I like to open the hood, it's usually good for a couple WTF's :confused:

this is the exhaust side... this pipe was replaced with a custom made aluminized modern exhaust pipe, & new full exhaust... the 100 HP flat head six sounds pretty awesome at cruise range RPM's... of course it usually wears a stock oil bath air cleaner

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one more pic of the outside ( for those who can appreciate an older classy lady ) this was taken a year & half ago, when I still had the aluminum slots on the car... loved the look, but all the shows kept putting me in the street rod class, because of the wheels... I'm next to a 1938 2 door sedan Nash Lafeyette ( the 1938's are pretty low numbers, & kinda rare, so to see 2 of them together, is pretty unusual )

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Ok....the top pulley is that simply an idler of sorts?

If so, could you remove it, fab a bracket to mount the alt above the gen and then still drive the gen off the same belt as the alt? so you'd have the alt, the crank pulley and the gen acting as a idler/pump drive.....the gen would be simply a drive for the water pump....and an adjustable idler....

honestly, looks to me like if you substatuted the alt for the gen and then mounted an aux 12v water pump drive motor you'd have it made....wish I could draw but I am artistically challenged...lol...two ideas for what it's worth....
 
Take a look at VW generator. It has shaft coming out both ends of generator. The older cars where 6 volt and in 67 changed to 12 volt. Regulators are small and easy to install. Go 12 volt or go 6 volt your chose.
 

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