Oils of yesteryear

[Richard1]

Many of you have read my paper on oils, specifically aimed at the selection for classic cars with flat tappets.

One of the thousands of readers sent me a sample of oil from the late 60's, so I had it analyzed and added the results to the report. The full (updated) report is here:
Selection of oil for flat tappet engines

For those only interested in the synopsis, here goes:

After a 30 minute shake to get everything in solution (not that it hadn't gotten shaken a bit in the mail), the can was opened and 120 mm was sent out to my lab for analysis.

This sample can had MM-MS-DG stamped on the top of the can, which means, in the current API system it would have met SC standards of 1964 or their upgraded 1968 standards for SD (both called MS back then), and DG means a CA for diesel use. The use of the word "plus on the label might have signaled the higher level that became "SD".

Additives are strange.....
First because it uses 124 ppm of barium. That is a DEMULSIFIER that would try to separate water from the oil. Obviously discontinued as that would cause more rust and sludge. It is more often used in turbine oils to separate the water in the drain area of the tank.

The normal additives are:

Calcuim (detergent): 807 ppm (vs about 1800 top 2000 for an SN and 3000+ for a CI-4)

Phosphorous (part of anti-wear package with zinc): 482 ppm (vs a minimum of 600 ppm and maximum of 800 ppm for an SN oil today and about 1300 to 1400 in a CI-4 - limited to 1200 in a CJ-4)

Zinc (part of the anti-wear package with zinc): 517 ppm (anti-wear packages have about 10% more zinc than phosphorous in any formulation that uses ZDDP).

So this was a post-1964 oil (possibly post 1968). It has a little more than half of what today's SN oils have in anti-wear and detergent, or about a third or less of what a CI-4 oil has.

When GM offered their additive to raise the ZDDP levels to this level or so, I can see why. But cannot see the need to raise it higher than CI-4 with the aftermarket additives on the shelves.

[azdave]

Thanks for keeping us all in the know on oil related issues. Nice to have an expert here to separate the truth from all of the rumors.

[gbarron]

Interesting info! I have read your articles and appreciate the knowledge you have shared on oil selection.

I found Caterpillar DEO has the CI-4/SL rating you suggest in both 10W30 & 15W40 grades (see attached Spec Sheet). What are you thoughts on using this brand in the 10W30 grade?

Thanks!

[Phil Dally]

For those of you that don't know Richard1 is an absolute authority on this topic and you can take his advice to the bank!!!

[doug66monza]

Richard, thank you for the information that you provide on oil specs and types suitable for our engines. At a recent show and shine in Edmonton Alberta I was handed a pamphlet from a company called Collector Automobile Motor Oil Ltd. located in Calgary Alberta. They claim that the oil has been manufactured with the right amount of ZDDP for use in flat tappet engines. Their web address is http://www.camoils.com" onclick="window.open(this.href);return false;. I would very much appreciate your thoughts on this product and the claims that they make. Unfortunately at this time the oil appears to only be available in Canada.

Thanks for your input.

Doug

[Richard1]

I wish I could say something better than what I'm about to say, but I'm not impressed.
First, some of their stories cannot be blamed on reduction of ZDDP. There were other factors.
Second, they confuse terms.

SM America Petroleum institute (API) oil has 800ppm of ZDDP

SN America Petroleum institute (API) oil has 600ppm of ZDDP

The reality is that in both SM and SN oils, the limits are 800 ppm of zinc and 600 ppm of phosphorous. The combination of the two additives make up the ZDDP. SN limits how much of that can evaporate in use. SM oils were/are notorious for evaporation of the additives.

I can't find a full spec sheet to see what their real levels are. "1600 ppm of ZDDP" is not something is measured. You measure the ingredients.

This statement is almost funny (I mean laughable, but sad)

By using 15W40 oil it takes up the space left by the absence of impurities making your engine feel tighter and stronger.

And finally, especially for Canada, the recommendation and arguments for 15W-40 are way off base.

[doug66monza]

Richard, thank you for your quick response and input. It is much appreciated.

Doug
1966 Monza Sport Sedan

[scottydont]

Great article! I know it wasn't the primary scope of the article, but I wonder if you can address the effects of high temperature on various grades of oil or oil bases as it ages? Since air cooled engines tend to run higher oil temperatures than other engines, that might be a factor in oil choice as well.

Also, do you have any information regarding the evolution of viscosity modifying polymers over the years? I can't remember if it was you or somebody else; but in a conversation a few months back, somebody on the forum stated that today's non-synthetic MV oils are more resistant to breakdown over time than those of the mid 90's due to better polymers. The article didn't say anything about changes to the polymers over time and it would be good information to have in my opinion... Kind of akin to the comparison of phosphorus and zinc levels of the 60's vintage oils.

[Richard1]

Great article! I know it wasn't the primary scope of the article, but I wonder if you can address the effects of high temperature on various grades of oil or oil bases as it ages? Since air cooled engines tend to run higher oil temperatures than other engines, that might be a factor in oil choice as well.

Also, do you have any information regarding the evolution of viscosity modifying polymers over the years? I can't remember if it was you or somebody else; but in a conversation a few months back, somebody on the forum stated that today's non-synthetic MV oils are more resistant to breakdown over time than those of the mid 90's due to better polymers. The article didn't say anything about changes to the polymers over time and it would be good information to have in my opinion... Kind of akin to the comparison of phosphorus and zinc levels of the 60's vintage oils.

Almost any oil in the market today is more resistant to heat degradation than those of 20 years ago. And if you go with a group II, which is most of the product made in the US, you have "enough" resistance to heat over time, but a Synthetic will hold up much better, especially in Turbos, since the turbo is much hotter than the rest. The biggest problem with Turbos is that people shut off their engines without cooling the turbo. Pull off the highway to buy gas or stop at McDonald's and you should let the engine idle for 3 to 5 minutes before shutting it off. Worse yet if it is for gas, since in a few minutes you will start it and the bearing will be expanded to the max with the coked oil on it.

VI polymers are in general much improved, but you can buy all types. An oil formulated for price will use cheap ones that will shear permanently in 1000 miles or so. But buying the most expensive, least resistant polymers is not necessarily the best solution, since if you oil has a tendency to oxidize, it will thicken up too fast. You want it to shear as the oil oxidizes.

The other factor on VI improvers is that a group I base oil may have a natural VI of 80, so to get 130 you need to add enough polymers for 50 points. With a Group II, you might have a base index of 100 to 110, so you would only need 20 to 30 points with polymers. A group III Synthetic (the famous Castrol Syntec and most others on the market) are in the 110 to 120 or so range, so need fewer yet. A group IV synthetic has no polymers.

Today's API testing goes a lot farther into what happens over time with tests to insure that performance is retained.

So when you look at a brand with a cheap and an expensive version of an oil, look at the above and you will know how they do it.

[Bob Helt]

Richard 1 stated:

The reality is that in both SM and SN oils, the limits are 800 ppm of zinc and 600 ppm of phosphorous.

Bob replies:

This really isn't true. Both SM and SN oils are spec'd at a max of phosphorus of .08% and a minimum at .06%.

AND this phosphorus spec is only for oils with a max viscosity of 30 (i.e., GF5 oils). SM and SN oils having a higher viscosity (eg 10W-40) have NO phos max requirements.

The amount of zinc is NOT spec'd at ALL!

Bob Helt

[Richard1]

SM and SN oils having a higher viscosity (eg 10W-40) have NO phos max requirements.

Technically, that is true, but the reality is that most manufacturers use the same additive package.