VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 what engine oil for 1950 Truck

My dad and I purchased a very nice 1950 3100 truck earlier this year and decided I wanted to change the oil after putting on maybe 80 miles on it. Was recommended to use a heavy oil 20-W50 but what I drained out was certainly more viscous or thinner than what I put in. I drained the old oil from the pan and also from the filter canister. I read online that both the 216 and the 235 took 5 quarts but I drained all together closer to 6 quarts.
I’m wondering if this oil it too thick. I ask because I ran the truck for just a few minutes and two things worry me.

1)the dip stick comes up dry. Certainly could be the extra quart I removed but did not yet put back OR maybe this oil is too thick to properly flow. Dip stick registered oil before I changed it.
2)I opened the oil filter canister and the oil was up to the VERY top. When I drained it, it maybe had ½ a quart in there but not like it is now.

Wrong oil or just need to add that missing quart or BOTH??? Appreciate any thoughts, thanks. I know this is just a pic of the outside but if you were curious 1950 Pic from GSBR VCCA

If the truck has the original engine it calls for a "thinner" oil. Todays 10W-30 is the first choice.
The engine takes 5 quarts + one more Qt. for the filter.
The reason the filter was full to the top is because it takes quite a while for the thick oil to pass through the tiny hole in the filter (when not under pressure) and return to the pan.
At this point if it were mine I would just replace the oil in the engine and fill with 5W-30....That will balance out the oil that stays in the pan and what is in the filter.
The reason for using a thinner oil is the type of oiling system. It depends on a thin mist of oil to be thrown onto the cylinder walls, wrist pins, etc.
When new they call for #10 oil below 10 degrees and #20 above that....and #30 for areas where the temp. staed above 90 Deg. for long periods of time.

Very great looking truck

Thank you for this information, I'll go get some oil tomorrow and replace.

Any thoughts on using an additive like slick50 or zmax?

Not needed. Save your money.

Modern motor oils contain all of the necessary additives for a 1950 engine.........and more.

So my 235 is new and normally above 20 degrees and below 90 most of the time.
So is that 20w
Or 20w-30
Or 5w-20 ?
Or something else?
Sorry don't know my oils
Thanks

They don't even make #20 or #10 oil any more.....use 10W-30 all year around. That was one of the recommended choices when 10W30 came out in 1954.It will cover anything from 20 below zero to 100 Deg.

10W-30 is the oil that you want to use.

Gene,
What's your opinion on zinc additives like ZDDP?? I read that the new oils have lower zinc levels to prevent cat converter damage. ????

Rick, not Gene here, but can say the current zinc levels in todays modern oil is still more than sufficient for our "aged" engines. No need for ZDDP additive.

There is enough ZDDP in modern oils for a 235,216,207 or 194 engine. When these engines were new there was no ZDDP (Zinc) in the oil and they survived just fine.
Where either an oil with additional ZDDP or an additive would be advised if your above mentioned engine has a new camshaft and lifters (or you have a high performance V-8)as some of the new cams were (are) not properly hardened. Also too much ZDDP is not desireable.
Also avoid racing oils as they do have more ZDDP but lack other additives that are desireable in passenger car day to day use.

We can easily recall the days of the GM "soft cams".

Yes, i was around in those days. Actually we never had a 6 Cyl. cam go bad. The first we saw was on the 8 cylinder engine and when the oil was not changed often enough. The intake would be removed to replace the cam and the lifter compartment would have sludge two inches deep. The problem resurfaced in 1977 and was a real problem. The factory picked up the tab on these engines and it made the mechanics mad when they tore down the engine and found it loaded with sludge.
I had a few of these engines adn never had a problem Would buy a two year old former leased car and drive it a few years, sell it to one of my kids or a friend and they would go 150,000 miles with no cam problems.....but you had to change oil every 2000 miles at least.


What does ZDDP do in the oil? It is suspended in the oil and does nothing unless the oil is squeezed out and the parts rub together dry. It then sticks to the hot metal and provides some short term lubrication. It does not work when cold or on an oily surface. Would be like when you use a chassis grease with moly or grphite.
Modern oil also contain some moly. These additives do get "used up" so changing oil is important.

One more thought, regarding the V8 "soft cams" and the "piles of sludge" within the intake valley.

Remember the "BLACK", AC oil filters, which were factory installed ?

Too many times to count, we towed cars in (V8), with engine failures, 20,000 plus miles, then noting the vehicle still had the factory installed "BLACK" filter. Replacement AC oil filters were blue in color.

No maintenance = sludge = no run = no warranty.

Actually al AC oil filters were black at one time. They changed to the blue in about the early 1960's.
I have the info. some place because the Corvair Clb requires the correct color/year for judging.
I have black, white and blue AC filters in stock.

Interesting info on the earlier filters.

My factory black filter comments were based on cars, after the "soft cam era".

I will have to think back on that.

Hi Bob,
That may be true for aged (old) motors, but my various readings indicate that rebuilt engines do benefit as "camshaft scuffing" can occur on new cams without the older ppm levels of zinc. In other words, an old motors are fine as the zinc has been absorbed but new cams require more.

I err on safety and have been running ZDDP based on my engine builder's advice. Just curious.

Happy Holidays, Bob.

Regarding zinc, I was speaking of "aged" engines and not current rebuilds.

That was my guess, Bob.

Anyhoo, Happy Holidays!!

Happy Holidays to you, as well, Rick.