Hey i had a couple questions does a 1948 oldsmobile have a negitive ground or positive ground i connected it via negitive ground and the battery posts started to melt probably have to redo some wiring it looks pretty bad
also the flat head 8 is stuck so bad that im going to have to pull it in order to free it THANK YOU

 

This would make a good epitaph. Right up there with "give me a match, I think my gas tank's empty."

The usual approach is to CHECK such things before hooking up wires. Yes, your car has a positive-ground system. You can determine this for yourself by looking at where the positive and negative battery cables attach to the car. On a negative-ground system, the negative battery cable attaches to the engine block while the positive cable attaches to the starter. For a positive ground system, this is reversed. Just looking and seeing where the positive cable attaches to the engine will be enough to answer this question. It wasn't until about the mid-1950s that automotive electronics moved to negative ground (and 12 volt electrics).

 

Take the opportunity to switch to a 12V system.

 

I think I beg to differ with that. I was not aware of Oldsmobile using positive ground systems. I had a '52 98 and I'm pretty sure it was negative ground. I know my '51 Chevy is. I recall Packards being positive ground, but that is not something that I thought Oldsmobile did, at least in the post war era.

 

FYI:

https://classicoldsmobile.com/forums...ve-ground.html

 

my 49 6 volt v8 is neg ground

 

Yes , your 48 Olds 98 is NEGATIVE GROUND .
You mention the engine was "stuck" . There is no such thing as "freeing it up " . Once cylinder walls have become rusted , even if the engine is "un-stuck" , the rust will eat up the rings and the engine will still need an overhaul . It's best to just remove the engine and dismantle it . Then take it to a good machine shop , and follow their recommendations . Parts for this engine aren't usually cheap , but they can be found .

As for " the battery posts started to melt " , Did this happen after you tried to turn your "stuck" engine over with the starter ? And possibly with a 12 volt battery ?

And finally , I would NOT recommend a change over to a 12 volt system . It is totally un-necessary in a collector car . And usually causes more problems than it solves.

 

Thank You all for your replies a lot of the wires are pretty bad so a short could explain the melting battery terminals heat shrink should fix that as far as the engine 3 of the pistons are confirmed stuck i'm hoping once the engine is pulled and taken apart that i can save the pistons after knocking them out one other thing does anyone know where i could find and original driveshaft for the car (4 door) as it was missing when i bought it.

P.S. i did try to bump the starter when i first got the car and the starter worked and so did headlights but i started recovering the wired since then so so could be bare because of the movement :]

 

I've thought about buying a 12v universal harness but it would be a pain to figure out besides most of the really bad wires are under the hood the ones under the dash look ok like my 51 chevy truck

 

Most of the problems with 6 volt systems are because of the use of 12 volt battery cables being used rather than the correct 6 volt heavy duty cables . 6 volt systems need much larger cables. You can usually find them at a tractor supply house.... Tedd

 

 

Joe P has linked a supply house in the past that provides aftermarket battery cables. Supposedly they have good prices and good products. Here it is:

https://www.batterycablesusa.com/

 

 

You can unsieze the engine if you work at it long enough but it might not have much longevity as others said.