T/A oil weight.

[eaglescout526]

Alrighty I got one for ya guys since oil weight makes controversy around here. If you guys were (and those of you who down own) to run an oil weight in your vintage engines(prior to EFI era), specifically a 403 olds, what weight would you use? 
 

I haven’t done an oil change yet and the internet is not fruitful for a specific oil weight, but I have some 20w50 I’m gonna run and use since it’s free oil from my other grandfather. 

[89 MJ]

I'm running the same conventional 10W30 Valvoline in my Eagle, garden tractor fleet that I run in the Comanche, and when I change the oil in the '40, its getting the same stuff. The Eagle, Comanche, and '40 get/will get zinc additive when I change the oil too. 10W30 seemed to be the oil to go with at at the time. IIRC, that's what we run in all of the old cars at work too.

[eaglescout526]

I was thinking 10W30 too. It’s a good oil weight for out here. 

[Pete M]

do you have an oil pressure gauge?  (specifically one that you trust?)  too thin or too thick might show on the gauge. 

[eaglescout526]

14 minutes ago, Pete M said:

do you have an oil pressure gauge?  (specifically one that you trust?)  too thin or too thick might show on the gauge. 

I trust the one in the car, it generates 40 psi and maybe a bit more. I will probably have to hook up a mechanical to make sure the gauge isn’t lying but I also haven’t done much ground cleaning yet. But it sounds healthy for only 62k on the clock. 

[75sv1]

I don't see an issue with that era, size and your location of 20W-50 conventional oil. In my '75 Bricklin with a 351W, I did that once. I might have been in Tulsa at the time. I lost 2 MPG though. Is the 40 PSI at idle or what RPM? I've heard of 10 PSI for every 1,000 RPM minimum. I might run at least 10W-40 say Spring and Fall, 10W-30 Winter, and then the 20W-50 during Summer. I'd also add Zinc or have 1,000 to1,2000 PPM of zinc. Since its a flat tappet motor.

[eaglescout526]

I think the oil pressure is between 40 and 60 from what I remember seeing but I haven’t had the car run long enough to get to temp nor drive it yet. Been trying to figure out all the vac lines and what not. 

[eaglescout526]

Ok so I thought I had more 20w50 but I have a lot of 15w40(regular, don’t go bananas guys. It’s older penzoil stuff)from my grandfather to use so it’s just as good to run it for a bit. 

[75sv1]

Depends on what 'older' means. Early 80's, or 2000+? Also, I think the older engines take thicker oil better. I did have an issue with my 2000 Ford Contour SVT and 20W-50 synthetic. The lifters didn't like it. I only ran it 3K. The 80's Pennzoil and Quaker State had a lot of paraffin in them. Also, they were good for say 2K or so. 

     I did run Castrol Syntec in my '96 Contour from 20K to probably 120K. Engine was clean. I did change to Shaffer them Pennzoil Platinum. All were fine in that motor. It never used a drop of oil, even at 214K. I sold it about then. 

[eaglescout526]

Here’s the oil in question. If I had to say I think this is the 90’s. I am not sure what engine my grandfather had that required this stuff unless it was on sale. 

[jdog]

Picture of the back side?

[eaglescout526]

58 minutes ago, jdog said:

Picture of the back side?

[Htchevyii]

I've found the 15w40 Delo or Rotella to work well in older engines, (as have many others). The diesel oils still have more anti-wear additives than regular oil, but not as much as they used to. The viscosity seems to be a good compromise and it's relatively inexpensive by the gallon.  I've also been adding 2 ounces of Redline break in additive per oil change. Proceed with caution if you have a catalytic convertor as the anti wear additives can foul them.

[Htchevyii]

Hmmm, just read the article a few posts down. Maybe the diesel oil isn't as good as it was made out to be?

 

 

[eaglescout526]

I appreciate the input on the diesel oil but I am staying away from that stuff. I’ll run engine oil with a 1/4-1/2 a quart of ATF before running diesel oil in any of my engines.

I’m just more curious on what was commonly used in the 70’s and 80’s as I don’t have an original owners manual at the moment and I haven’t looked in the Hayes manual I have but I know I have the oil above that I can use since it’s free and figured I’d get some opinions on the use of said oil. 

[89 MJ]

I’d be a little worried about that old oil starting to break down some. 

[acfortier]

Yeah, I think after 5 years for conv. oil, and like 7-8 for syn. oil, they start to break down, even if they haven't been opened. I wouldn't use that Pennzoil.

[eaglescout526]

That’s all I needed to know. Course I’d just like to use this oil as a flush and light use. Say maybe 100 miles or maybe a run time of 4 hours total. 

[acfortier]

Meh, oil is cheap enough, I probably wouldn't risk it

[FrankTheDog]

Me personally I’d run a modern synthetic in 10/40. Oil technology is advancing all the time. I’ve mostly used synthetic for the last 20 years on anything that I was going to keep. 
I never have had any internal engine problems or oil burning in anything I’ve had. Most were high mileage vehicles when l bought them.

Oil is cheap compared to an engine rebuild.

 

 

[gogmorgo]

In a pinch, most liquids are better lubricants than air. It’s probably fine if you’re just using it with seafoam or something as a quick flush and won’t be beating on the engine while it’s in there.

But of note, that penzoil is a diesel oil. More specifically it’s a mixed-fleet (one-size-fits-all) oil, but 15w40 is consistent with diesel engines. CH-4 is the diesel standard introduced in ‘98, SJ for the gas engine standard was largely replaced by 2002 if you want a narrower window on its age, although the API still considers both specs to be “current”. (I think that means it’s still acceptable for production, you might see it for sale at the dollar store but wouldn’t necessarily want to stick it in a modern turbocharged engine sorta deal)

So if you don’t want to run a diesel oil…

 

[eaglescout526]

8 hours ago, gogmorgo said:

But of note, that penzoil is a diesel oil. More specifically it’s a mixed-fleet (one-size-fits-all) oil, but 15w40 is consistent with diesel engines. CH-4 is the diesel standard introduced in ‘98, SJ for the gas engine standard was largely replaced by 2002 if you want a narrower window on its age, although the API still considers both specs to be “current”. (I think that means it’s still acceptable for production, you might see it for sale at the dollar store but wouldn’t necessarily want to stick it in a modern turbocharged engine sorta deal)

So if you don’t want to run a diesel oil…

Hmmm. Now that you point out the meaning of those symbols on the back it would be hypocritical of me to run this oil. Seeing gas and diesel on the label is misleading and made me think it should be regular oil and none of that special diesel oil blend. 
 

I wonder if my grandfather had this stuff from when he owned a diesel Mercedes for a bit. 

[FrankTheDog]

I wouldn’t run that oil in anything you cared about.

Only thing l would run it in is something that’s already leaking or burning a lot of oil.