New oil in older cars

6

'61 Draggin Wagon

Well-known member
I've been hearing rumors & just read a couple of articles about todays newest oils & how they do not properly lubricate older engines with flat tappets (non-roller lifters). Seems as though, to meet the latest emissions specs, the manufacturers have asked the oil companies to remove a certain additive (ZDDP, if memory serves). This additive is crucial for high stress parts. Among the items that are suffering high wear & early failure are distributor gears, timing gears & cam lobes/lifters.
From reading these forums, this sounds like a familiar problem among us.
Anyone else read about this?
Darryl
 
8) yep. a lot of guys either add gm's engine oil supplement or use shell rotella t diesel rated oil. there are a few others on the market that have not lowered the zddp additive as much. someone posted a chart as to what oils had what in them.
 
You talking about just the dino oils or also the Synthetics as well?
 
I believe it is due to the removal of Zinc from modern engine oils in an effort to reduce emissions.

Supposedly there are still a few oils out there that have it. the Hamb has a bunch of good threads on the subject.

I will point out tho that most of us don't drive our 6's enough for it to really matter.
 
I drive mine daily...
Zddp reduction is for "better emissions" in a roundabout way.
New car warranties are much longer now, and it is being removed because as a car ages, more oil is burned, and the zddp starts coating the catalytic converter, slowly reducing it's effectiveness.
Rotella T Diesel oil is best common oil for zddp right now, but even that has been reduced. Most of the racing oils are real high in zddp, and, as has been mentioned, there are additives available to replace it.
Other solutions are roller lifters or composite base lifter.
Rick
 
I used to drive my mustang daily on regular Dino oil. I can say that with 60k miles in the past 4 years, no problems with the oil.

I suspect that some of the problems is that the cars are suffering from old age and these parts are wearing out as part of the normal, 45+ year cycle. Keep that in mind too.

Slade
 
I read on another board that that Gm stuff is NLA.

I also read that the typical stock motor (especially a 25+year old one) does not run high enough spring pressures to really have a problem.

I have a friend that just became a small engine tech/dealer for Honda, Kohler, Tecumseh, and Briggs and Startton. Durning the classes people asked the same question and their answer was that their oils fall under the same regulations as the auto ones therefore have the lower or no levels zinc but with the spring pressures they tend to run its not a problem.

Seems logical to me but Im easy to convince and dont have enough miles on my new motor to know if there is a problem. I did find out I could see the cam through the oil drain holes with a bore scope so I will keep an eye on it.
 
No ZDDP additives here in Europe, so I had a little chat with the guys at Bardahl.
Since nobody over here seems to be aware of the dreadful zddp-situation, they had to check back with their chemists in the States first, then after two more weeks, they reported back and recommend something even more effective (and even more toxic) than ZDDP: lead-based ( :shock: ) industrial grade additives originally designed to protect stationary engines and transmissions from excess load damages.
reportedly, this stuff even helps with pitting on older cam lobes, to a degree.

Might be worth a shot, in case GM EOS becomes unavailable one day (it already IS, in the Old World), or if someone needs a little more protection for a 14:1 race engine...
 
This discussion started about 4 years ago. There was and still is a high failure rate of the lifter / cam surfaces failing on new rebuilds. This is the only area of the old engine design that needs oil that can handle high pressures during the break in. Apparently the Zinc-Sulfur additive provides a coating on these flat surfaces that gives these high pressure areas a better chance of surviving during this break in period.

Do a search for ZDDP on this site. There is one string that provides links to other sites that have studies published that will help you decide.

Good luck, Ric.
 
One article that I read dealt with a new distributor gear failure & testing. Another was a rebuilt MG engine that ate a lifter & another were a number of GMC 302(inline six!!) cams on fresh rebuilds.
Being that I'm running double valve springs & I've read about a number of distributor gear failures on here, I thought it would be a fitting subject....
This has been a great thread!!
Thanks all!
Darryl
 
When I picked up my head and block from the machinist I asked him what I should use for oil.

He said to run a premium grade diesel oil or a racing oil.
The diesel would be more practical particularly in cold weather.

He has rebuilt a number of high performance engines that had had cam problems due to the use of synthetic oils.
 
I'v been told STP oil treatment has ZZDP/ Zinc in it, dosn't say on the bottle tho. could ask the counter person at the store for the MSDS on the product, that will tell.
 
one of the best good diesel oils is Chevron Delo 15W 40.

Do NOT, however, get the new "LE" (low emissions). It's junk, as mentioned above.

I can still buy in 5 gallon buckets the good stuff at NAPA. But stock up now, it won't last forever.

John
 
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