Check out the lubricants specs for '42-'47 Chevys...

[Big O Dave]

I found this while searching for oil viscosities to use at various ambient temperatures, I found this page out of a 1942-1947 Chevrolet Shop Manual. As soon as I saw it, I thought some of you might find it interesting, especially since we consider SAE 20 motor oils to be so controversial. Take a look! 1942-1947 Chevy Lubricant Specs

 

[gj]

i like the add kerosene suggestion

 

[ALS]

I like the second page which recommends changing the oil between 2000 and 3000 miles. Gee I didn't know the quality of engine oil hasn't changed much since the 1940's. Is iffy lube recommending their oil change intervals based on 1940's automobile service manuals.?

 

[ekpolk]

. . .or maybe the stuff in their bulk drums is about the same quality as the oil GM was recommending in the mid-1940s. Of course, one other thing to keep in mind is that back then, engines were not expected to last anywhere near as long as they are today. Surely, many other things contributed to the shorter life of those engines, but it is still something to think about. Also, most of the kero based engine flushes that can be bought today contain dire warnings that while they are in use, the vehicle should not be driven and it should only be run at idle. I'd love to see a UOA from a 1940s engine run at deep freeze temps and filled with 10w oil cut 10% with kerosene!

 

[Spector]

Wow, other then changing the oil and transmission fluid once in a while todays cars are pretty maintenance free compared to that manual, way too many things to oil, grease etc

 

[MolaKule]

You also have to consider that the finished oils' VI's were pretty narrow back then in them there days! And the quality of the VII's to even make them W weights were pretty archaic compared to today's VII's. In addition, the oils were changed about every 1,500 miles. Sludge monster's Unite!

 

[JavaMan]

One day people will nostagically look back at lubrication in 2005. I wonder what they will think?

 

[Curious Kid]

Thanks for the link Dave...I love seeing the breakdown.

 

[bruce381]

"You also have to consider that the finished oils' VI's were pretty narrow back then in them there days!" Narrow?? That fits a boiling range better than a discription of VI in fact back then VI's were all over the place with solvent extracted oils being the best if made from Pennsylvania crude and with Coastal Pale oil's thrown in VI were wide rangeing Id guess from a minus number to at most about 50-70. Bruce bruce

 

[Audi Junkie]

In those specs I expected to see Cod Liver oil or something.

 

[G-MAN]

quote:

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And the quality of the VII's to even make them W weights were pretty archaic compared to today's VII's.

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You've got me scratching my head over that one. Straight grade 10w or 20w oils back then would not have had any VI improvers. They may have had some archaic pour point depresants.

 

[G-MAN]

quote:

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If using a monograde oil a lighter one like a 20W will make for easier starts than say a 30W or 40W. As I recall a current 30W monograde HDEO like the commonly available Delo...

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There is no such thing as a 30w or 40w oil. 25 wt is the highest viscosity oil for which the SAE stipulates cold cranking performance specs, i.e., the "w" rating. What I find interesting about the mid 40s GM factory fill is that it was a 10w oil. I knew in the 50s and 60s 20w20 was pretty much standard factory fill in Detroit, but I didn't realize 10w had been at one time.

 

[1sttruck]

Yup, no 'W' on the other Delo oils besides 10W. So it seems that for any cold cranking spec one needs to use a lighter oil. http://www.chevron.com/products/prodserv/nafl/trucking/content/prodspecs.shtm Chevron Delo 400 SAE 10W, 20, 30, 40, and 50 are manufactured using carefully selected premium paraffinic base oils and an optimal blend of the latest technology in dispersant, detergent, oxidation inhibition, antiwear, corrosion inhibition, and defoaming additives.

 

[Big O Dave]

quote:

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Chevron Delo 400 SAE 10W, 20, 30, 40, and 50 are manufactured using carefully selected premium paraffinic base oils and an optimal blend of the latest technology in dispersant, detergent, oxidation inhibition, antiwear, corrosion inhibition, and defoaming additives.

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... AND, these Chevron monogrades are all made with Group II base oils, per an email and a phone conversation with Chevron.

 

[1sttruck]

If using a monograde oil a lighter one like a 20W will make for easier starts than say a 30W or 40W. As I recall a current 30W monograde HDEO like the commonly available Delo provides excellent protection provided you can avoid too many cold starts. Once multi-weights became available makers seemed to gravite to heavier oils.

 

[JohnBrowning]

I think it is diffacult at best to try to compare 1930-1940 Sae 10,20 or even 20W20 to a modern 5W20. The engine materials,clearances,tolerances,tbo's,expected life cycle etc....were all different! For what it is worth Ford Model T's shiped with 600 weight gear lube in the rear end.

 

[Jimbo]

That is a great site. Thanks for the link. A few comments. Cold starting, not long engine life was the priority, since they had 6-volt systems and after WWII, car engines were not expected to last very long, maybe 50-60,000 miles. Acid and clay treated oils, not even close to todays Group I, had so much residual wax that they did not flow well cold. Adding kerosene to the crankcase was "homebrew" solvent refining. Chevrolet engines back then did not have full-pressure lubrication. The rod bearings were lubed with a "dipper" scoop on the bottom. Thick oils probably dont work at all with that system. Operating oil temperatures were lower in these low rpm low horsepower (by todays standard) engines . If you look at one of the oil specification charts, the viscosity was measured at 138F, not the 210F that is the SAE standard. True operating temperature viscosity of SAE 20 at 138F may be comparable to SAE 40 at 210F.

 

[subaru1991]

This is an interesting thread. from Jimbo... "Cold starting, not long engine life was the priority, since they had 6-volt systems and after WWII, car engines were not expected to last very long, maybe 50-60,000 miles." How and why did engines change after WWII so that engine life expectations were reduced?

 

[Crashbox]

I agree with Jimbo that the "splashers" and thick oil do not mix. FWIW, I heard from an old-timey mechanic many years ago that splash-lubed vehicles should not exceed 55 MPH because of possible oil starvation... His advice does make some sense to me though it's been a little while since I drove a splasher!

 

[PandaBear]

So what is Pennsylvania crude? Was it the "synthetic" back in the days?