dlpalumbo

Yeah Mixter, I hear you. But I think his real motivation is to teach us that high zinc and phosphorus levels are not needed to get adequate wear protection for our flat tappet cams. If you look at the PDF file in original post, he tests ZDDPlus and finds it lowers wear protection. He cautions against using additives in the PDF. Now he has tested another another additive that increases wear protection in several oils. This is all about his building a case for the efficacy of his argument, I think.

The question I'd really like to get into is whether his argument against high zddp levels vs pressure rating indicating wear protection is valid. This would greatly influence the kinds of oils I'd be comfortable running.

Another related issue is oil weight. Do modern low weight oils provide protection at temperatures our engines operate? An oil that gives great protection at temperatures lower than it would see in our engines may not do as well in our engines.

​​​​​I think I'll look the community.

Thanks for your comments.

Dan

dlpalumbo

A fellow gear head has a blog that introduces an oil wear protection rating here.

The wear protection rating is in psi and indicates the maximum operating condition for that oil. The author contends that wear pressures over 90k psi are needed to protect flat tappet engine cams regardless of zinc levels. Here's a quote from the article:

In recent years there have been entirely too many wiped cam lobes and ruined lifter failures in traditional American flat tappet engines, even though a variety of well respected brand name parts were typically used. These failures involved people using various high zinc oils, various high zinc Break-In oils, various Diesel oils, and various oils with aftermarket zinc additives added to the oil. They believed that any high zinc oil concoction is all they needed for wear protection during flat tappet engine break-in and after break-in. But, all of those failures have proven over and over again, that their belief in high zinc was nothing more than a MYTH, just as my test data has shown.

Its a long read and there's lots of data to peruse. I'd like to know what the members think, especially if you're technically knowledgeable in a related field. This will greatly influence my oil purchase decision next fill.

My related thread is here.

The author identifies himself as 540 Rat. The 'rat' motor referred to a Chevy big block back in the day, 540 its displacement.

Thanks for your comments,

Dan

hacker-pschorr

**sigh**

Not that webpage again....it's been around a while, and many other threads started around it.

Define "high zinc levels"

Long story short:

1. Once upon a time, every oil had 1100/1200ppm of ZDDP or more
2. Sometime after 2000 the EPA changed regulations to save catalytic converts. This dropped ZDDP down to 800/600 or so.
3. Panic spread throughout the classic car community
4. Plenty of oils can now be found in the weights needed for classic cars with the "old" standard of 1100/1200ppm
5. Most "lower" levels of ZDDP oils today are much lower viscosity than we use in older cars
6. Find an oil with the same specs as when the cars were designed / build - see #1

I thought all you guys ran Mobil 1 V-Twin air cooled oil?

I merged your threads together, you don't need two active oil threads......

dlpalumbo

I wanted a separate thread to point the discussion at the specific topic of zinc levels vs pressure failure level 540rat suggests. The site may have been around a while but its info is up-to-date.

I consider high zinc levels to be above the 600 to 800 levels. The question is, "Should I bother considering zinc levels at all considering the info in 540rat's blog?".

For example I had been using M1 15w50 because of its 'acceptable' zinc levels ~1200ppm. I have been urged by my shop to go to Castrol 20w50. I searched for zinc level specs for the Castrol product and found 540rat's blog.

Castrol 20w50 has ~700 ppm zinc. That would be considered too low by our community for our engines. However, the Castrol product has a wear pressure of ~95k psi which is considered acceptable by 540rat for flat tappet engines. M1 15w50 comes in at ~70k psi which is way below the 90k psi recommended by 540rat.

540rat contends looking at zinc level is unnecessary. A wear pressure spec > 90k is all you need to protect your cams.

Whose convinced of this?

hacker-pschorr

You are overly complicating things. Simply run what the factory specified back in 1994 and be done with it.

"High" zinc levels are well over 1100/1200ppm, there are oils out there with over 2,000ppm (Mobile 1 V-twin has 1600/1750)
1100/1200ppm is nothing more than the "old" standard compared to the new EPA friendly version.
If that possibly bogus study on ZDDP effects on CATS never been released, every oil would still have 1100/1200ppm.

......and as others stated above, stop listening to anyone saying your engine shouldn't be used with synthetic oil.

HDA

Quadcammer

His problem is not that you use synthetic, its that you use 0w40, which is not the correct weight for an air cooled engine. its universally agreed that these engines need thicker cold weight oils

dlpalumbo

With Hacker-Pschorr's recommendation to run original fill, I set off to learn more about Shell TMO 5w40 per Bill Verburg's post knowing full well that this oil isn't produced any more and was likely not available in the States even if it were. And what I found was a very good explanation for not running synthetics from a thread on Pelican's forum here. I will quote M.D. Holloway's post:

" 0W40 scarestthe cr@p out of me! Synthetics have a pretty high viscosity index by their nature but in order to get that low temp viscosity (the 0W in the 0W40) you have to use a severely hydrotreated base stock or a 7 membered PAO - these actually make for some pretty great temp stability and oxidation resistence but they are pretty close to the molecular configuation of the phalates that are used to plastize seals - may pull the plastizers out and leave the seals brittle and suscpetable to leaks." and ...

"Phalates (sp) are chemicals that are used to plastize rubber - many synthetic oils actually mimic these and can draw them out of rubber seals making them brittle and suseptable to leaks and weakening. That is why many early and middle year p-car owners wouldn't use synthetics if they were free."

So there is a good reason to back off synthetics, especially ones that reach low weights. Also makes me think of my very brittle cylinder/case gaskets that were a big source of leaks.

Maybe the oil cans should have a phalate symbol on them as a warning.

Kappi2907

Go for Ester based oil, will stick better to metal.
E.g Motul 300v 15w40.

JasonAndreas

Which synthetic elastomeric seal used in the 964 engine would be affected?