Antique vehicle Engine Oil

[wimpy01]

Older, pre-emission-control models have been using engine oil intended for diesel trucks, e.g., Shell Rotella T, with the understanding that this type oil contains the additive zinc dialkyldithiophosphate (ZDDP), which does two important things for older cars:

1. Increased soot control
2. High pressure wear inhibitor, particularly important for camshafts

ZDDP is being phased out of all motor oil you can buy on the shelf because it is potentially harmful to catalytic converters. ZDDP is coming out of all API-rated (American Petroleum Institute) oil. In the near future Shell Rotella T will no longer give extra protection previously expected from that oil.

Anyone out there using these products? Anyone familiar with this problem and know what the best answer is?

 

[Quest]

While in general your observation is correct, I must say that if you happen to possess a prized vintage cars that pre-date the API SA rating, you shall seriously consider doing the following:

(1)perform a couple of oil tests to verify and ensure that you are not suffering from excessive cam wear due to soft or improper hardened camshafts.

(2) check to ensure that your engine seals are sealing properly when using modern API rated motor oils.

(3)perform internet search for motor oils customed for vintage cars. There must be some oils out there that are custom-blended for use in modern vintage car collections, with proper chemistry that would help in keeping everything working properly.

While I must say that ZDDP *may* help in reducing camshaft wear, its also been posted here sometime ago that ZDDP may not be the primary contributor in reducing camshaft wear but more to do with overall balance of many other EP-AW additives within the motor oil additive blend.

Send in some samples to Terry Dyson before you draw your own anecdotal conclusions.

 

[Blue99]

In the last 7-8 years, the levels of ZDDP have been reduced because the phosphorous component is viewed as one of the factors that would cause a cat to fail emissions testing before the 125K manufacturer's warranty expires.

And "soot control" is normally a term used with hevi-duty engine oils, HDEO's, to describe a detergent/dispersants additive function, not the anti-wear function of ZDDP.

But I have yet to see any news relating to ZDDP being totally eliminated.

 

[alreadygone]

Think I'd be a lot more concerned with lack of lead in fuels causing valve seat damage than oil additives.

Bob

 

[CBODY67]

I've been looking at and saving information on various motor oils (from their respective websites' data sheets) and have noticed that some brands have more zddp than other brands, including "SM" oils. Many of the "SL" oils have the same levels of zddp as a few "SM" oils do, with "SL" supposedly having (generally) more zddp than "SM" oils are supposed to. For example, many "SL" oils have about 12% of zddp, by weight, but this can drop when "SM" ratings come into play in many brands. Not all of the oil company websites have the percentage of zddp listed on them, but many do.

As mentioned, zddp is not the only additive that will work to do what it's supposed to do, just that it became the most cost effective for many companies to use. Kind of like tetraethyllead (TEL) being used to boost gasoline octane rather than use more expensive refining techniques to get the same octane (valve seat issues aside).

Even the new gen Rotella T is an "SM" rated oil, which I suspect is more of a reflection upon the new (basically) "zero suphur" fuels and similar related things.

One thing about vintage engines and camshaft wear is that with their low mileage/year (about 3000 miles/year to use antique insurance on those vehicles), it will take many years to accumulate enough miles to determine what's going on as to additional wear of camshaft lobes on "SM" rated dino oils. In the mean time, if there is a concern, it might be advisable to stock up on "SL" rated oils that are still on the market now and/or get some GM Engine Oil Supplement Concentrate to add at each oil change. Some of the rubber seals in those engines might not be compatible with synthetic oil, so that might not always be a viable option in this case.

Although the OEMs are driving motor oil standards, there are still many older "flat tappet" engines out there. I suspect that until some comprehensive testing is conducted by a third-party entity, no conclusive evidence might exist in this area.

Comp Cams now has a "break-in" oil additive for their cams, which they also claim can be used with oil changes to make up for the "lost additives" in modern motor oil. GM's EOS Concentrate has also been mentioned. And now, even Comp Cams' notation of Shell Rotella T being recommended for use with their camshafts seems to be "gone" as the new Rotella T dino oil is "SM" rated. Seems to be something of a shifting playing field!

Just some thoughts,
CBODY67

 

[Herman]

ZDDP is being phased out of all motor oil you can buy on the shelf because it is potentially harmful to catalytic converters. ZDDP is coming out of all API-rated (American Petroleum Institute) oil. In the near future Shell Rotella T will no longer give extra protection previously expected from that oil.


The new Rottella T formula for the CJ-4 spec shows 1159 ppm zinc.

 

[wgtoys]

One thing to keep in mind with really old engines is the issue of oil filtration. Many pre 1960s vehicles came with no oil filtration. Aftermarket accessories to add a simple bypass style filter are common place and have been installed on many of these cars. With detergent type motor oils it is important to have some form of filtration. Non-detergent oils would let much of the debris settle to the bottom of the oil pan, but detergent oils are designed to keep this stuff in suspension in order to carry it to the oil filter where it will be trapped.

That said, I plan to keep using 15W-40 dual rated oils in my older vehicles. Even if the ZDDP is reduced, other additives will have to be in there to provide boundry lubrication. I'm pretty comfortable with the idea that an oil which is up to the job of lubricating heavy duty diesel engines will also do the job with old fashioned flat tappet gasoline engines.

As far as the unleaded fuel issue, the normal solution is to install hardened exhaust valve seat inserts. Machine shops have been doing this for decades.

 

[wgtoys]

PS The new oil GF-4 specification only applies to SAE 0W-, 5W-, and 10W- multigrade motor oils. Single grade, 15W-, and 20W oils do not apply. I'm not sure what the SM specification has to say in that regard, but I believe that it also distinguishes between the new car multigrade weights and the others.

http://www.ilma.org/resources/ilsac_finalstd011404.pdf

 

[427Z06]

Quote:

---

And now, even Comp Cams' notation of Shell Rotella T being recommended for use with their camshafts seems to be "gone" as the new Rotella T dino oil is "SM" rated. Seems to be something of a shifting playing field!

---

"SM" rated oil that are not the ILSAC grades (non GF-4 rated) don't have any phosphorus and thus ZDDP limitations! HDEOs that meet CJ-4 specs do have a phosphorus limit of 0.12% compared to CI-4 limit of 0.14%, but in either case, that should allow for plenty of ZDDP in an old flat tappet engine.

I wish some of you would do some research before perpetuating myths.

Here's some additional information:

http://theoildrop.server101.com/forums/showflat.php?Cat=0&Number=721645

 

[Syntec-Man]

My dad's friend has about 250+ antique cars! i will ask my dad what type of motor oil he uses

 

[Doc8404]

SYNTEC: what did he say?

 

[wileyE]

funny, when the cam manufactures talk about zddp they are experts. But when they say don't use synthetic, they don't know what they are talking about.

I agree the cams ground with agressive ramps need all the help they can get, it's always been that way. But thats how they make more power. The OEM grinds, even on old cars use long slow ramps for valve train and life of the motor durabilty, plus better steel. Don't see SM being an issue in stock old cars in the viscosity they recommend. Also many of the aftermarket cams get wiped in the 1st 200 revolutions of the new startup, then go downhill from there. Oil probably deserves some of the blame but not all, IMO.

 

[Syntec-Man]

He said he uses sae 30 ac delco