old car oil

[greenstangs]

I just got a 1938 oldsmobile 6cyl with what i think is 8161 miles on it. my question is when I go to change oil what to use since it does not have a oil filter. a diesel oil 15w40, straight 30 weight or 30 non detergent. when my uncle had it I believe he said he changed oil but that has been over 20 years ago but i do not know what he put in it.

http://i1182.photobucket.com/albums/x457/greenstangs/1938oldsmobilef380043_zpscceb6c19.jpg

 

[Zaedock]

Quaker State Defy 5W30 would be far superior to anything offered in 1938 and would work very well.

Absolutely no need to run a non detergent oil.

 

[dave1251]

Do you have a oil pressure gauge? I would go with a 30 grade. Remember in 1938 PCMO's were junk by to day's standards.

 

[greenstangs]

I does have a factory gauge

 

[Doug Hillary]

Hi,
greenstangs - Are these engines a derivative of the Chev 6? - I thinks they may be! If so they depend on splash feed and scoops on the rods - oil pressure is typically less than 30psi

These engines ran on SAE20 or SAE30 at the time

 

[artificialist]

My father told me that when an old engine ran with non-detergent engine oil for its entire life, detergent oil would sometimes loosen up so much sludge that it would clog up the oil pump pickup screen.

If the engine is fairly clean inside, then using a detergent engine oil is best.

I have read about some people saying that engine without oil filters should get non-detergent oil, but that can't be true anymore because lawnmowers and scooters use detergent oils.

 

[Zaedock]

Hi guys, the Olds I6 is not a derivative of the Chevy "Stove Bolt" OHV engine.

 

[Plumber]

Motor's specs SAE20 for summer.

Every old car I have owned, I drop the oil pan, clean it out, then refill with new oil.

 

[Merkava_4]

Valvoline MaxLife SAE30 from NAPA.

 

[Zaedock]

If you're going to run Maxlife, it makes more sense to use a 5W30.

 

[greenstangs]

someone told me to use 15w40 and when it starts to turn black to change it.

 

[Sunnyinhollister]

Shell Rotella T5 10W-30

 

[901Memphis]

Originally Posted By: Sunnyinhollister
Shell Rotella T5 10W-30


+1


Also do change often until you get all the loose sludge out.

You don't want to go too thick since it doesn't have a full pressure lubrication system.

 

[bvance554]

Originally Posted By: Zaedock
Quaker State Defy 5W30 would be far superior to anything offered in 1938 and would work very well.

Absolutely no need to run a non detergent oil.


As would any 5w-30...

 

[Garak]

Originally Posted By: greenstangs
someone told me to use 15w40 and when it starts to turn black to change it.

That would undoubtedly work, but, considering such engines called for SAE 20 in the first place, I would question the need to jump up two whole grades right off the bat.

 

[Volvohead]

If it has sat that long, you may want to pre lube the cylinders and hand crank it first.

Any HDEO 10w-30 will be fine in that. The 20w recommendation was more for cold pumpability. According to the service notes from that period, a straight 30 was for ambients 90F or above.

The OCI is 1-2k. I'd stick with 1k for the first couple changes, provided you drive it that much annually.

Don't forget to oil the air filter on those at the OCI. I think that takes a 40 or 50 weight.

 

[SS1970chrysler]

I'd run Rotella HD30 or 10w-30 in it and call it a day.

 

[greenstangs]

pulled the plugs yesterday and spraying fogging oil in the cylinders. I know the eng was not locked up but I do not know when it was ran last.

 

[Boss302fan]

Rotella 15W40....

 

[Volvohead]

Originally Posted By: greenstangs
pulled the plugs yesterday and spraying fogging oil in the cylinders. I know the eng was not locked up but I do not know when it was ran last.


If you can get your hands on something like LC20, start with that, and let it soak down overnight. Then a very light oil fogging before an open chamber hand crank.

What you want to avoid is a frozen ring, which can damage a piston land if you power crank it.