The Green Oil

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Hippie
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Post by Hippie » Mon May 03, 2010 6:47 pm

I positively trust Jake Raby's tests, but he's fighting a different battle than I am.
I'm not using Brad Penn specifically for the zinc, but for its clinginess. I mention the zinc as an aside for T-4 owners who may be in the same boat with Jake with the quesyionable aftermarket lifters. I have a T-1 engine, like the extra zinc, but am not super worried about not having it.

A little history from Bob Orlee - GM lubricants:

"The Starburst Oil Myth -- The latest myth promoted by the antique and collector car press says that new Starburst/ API SM engine oils (called Starburst for the shape of the symbol on the container) (fig. 3 and 4) are bad for older engines because the amount of anti-wear additive in them has been reduced. The anti-wear additive being discussed is zinc dithiophosphate (ZDP).

Before debunking this myth, we need to look at the history of ZDP usage. For over 60 years, ZDP has been used as an additive in engine oils to provide wear protection and oxidation stability.

ZDP was first added to engine oil to control copper/lead bearing corrosion. Oils with a phosphorus level in the 0.03% range passed a corrosion test introduced in 1942.

In the mid-1950s, when the use of high-lift camshafts increased the potential for scuffing and wear, the phosphorus level contributed by ZDP was increased to the 0.08% range.

In addition, the industry developed a battery of oil tests (called sequences), two of which were valve-train scuffing and wear tests.

A higher level of ZDP was good for flat-tappet valve-train scuffing and wear, but it turned out that more was not better. Although break-in scuffing was reduced by using more phosphorus, longer-term wear increased when phosphorus rose above 0.14%. And, at about 0.20% phosphorus, the ZDP started attacking the grain boundaries in the iron, resulting in camshaft spalling.

By the 1970s, increased antioxidancy was needed to protect the oil in high-load engines, which otherwise could thicken to a point where the engine could no longer pump it. Because ZDP was an inexpensive and effective antioxidant, it was used to place the phosphorus level in the 0.10% range.

However, phosphorus is a poison for exhaust catalysts. So, ZDP levels have been reduced over the last 10-15 years. It's now down to a maximum of 0.08% for Starburst oils. This was supported by the introduction of modern ashless antioxidants that contain no phosphorus.

Enough history. Let's get back to the myth that Starburst oils are no good for older engines. The argument put forth is that while these oils work perfectly well in modern, gasoline engines equipped with roller camshafts, they will cause catastrophic wear in older engines equipped with flat-tappet camshafts.

The facts say otherwise.

Backward compatability was of great importance when the Starburst oil standards were developed by a group of experts from the OEMs, oil companies, and oil additive companies. In addition, multiple oil and additive companies ran no-harm tests on older engines with the new oils; and no problems were uncovered.

The new Starburst specification contains two valve-train wear tests. All Starburst oil formulations must pass these two tests.

- Sequence IVA tests for camshaft scuffing and wear using a single overhead camshaft engine with slider finger (not roller) followers.

- Sequence IIIG evaluates cam and lifter wear using a V6 engine with a flat-tappet system, similar to those used in the 1980s (fig. 5).

Those who hold onto the myth are ignoring the fact that the new Starburst oils contain about the same percentage of ZDP as the oils that solved the camshaft scuffing and wear issues back in the 1950s. (True, they do contain less ZDP than the oils that solved the oil thickening issues in the 1960s, but that's because they now contain high levels of ashless antioxidants not commercially available in the 1960s.)

Despite the pains taken in developing special flat-tappet camshaft wear tests that these new oils must pass and the fact that the ZDP level of these new oils is comparable to the level found necessary to protect flat-tappet camshafts in the past, there will still be those who want to believe the myth that new oils will wear out older engines.

Like other myths before it, history teaches us that it will probably take 60 or 70 years for this one to die also."

- Thanks to Bob Olree – GM Powertrain Fuels and Lubricants Group

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Amskeptic
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Re: Zinc? or Just Old Age Showing...

Post by Amskeptic » Mon May 03, 2010 7:43 pm

The Air-Cooled Ranch wrote: I'm trying desperately to avoid stirring the pot -
Anyway - just some random thoughts to help keep things in focus.
Stir away! Your opinion is welcome. We do not conflagrate or boil over around here. Note that discussions here are not Vested Ego-Fests.

I have seen some amazing bearing corrosion. I have also seen just good ol' coppery shiny old beaten #2 bearings. I am fascinated at the corrosion bearings though. It looks like Martian drainage canals eating through surface layer. And it sparks my curiosity because it is clearly not mere wear. I have seen photographs of bearings subjected to chronic detonation impact loads, those bearings had "splintered" surfaces. Condensate acid is interesting stuff. What does it do to soft bearing laminates? I do not think lead was phased out because of environmental issues (kids, I told you not to drink that used engine oil, and I am not going to tell you again), but rather that specific output has now exceeded the old bearing metallurgy. Yaah?
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Hippie
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Post by Hippie » Tue May 04, 2010 2:50 am

In addition to what he wrote about zinc "not having better things to do"...having myself seen a number of perfectly uncorroded bearings that sat in what was probably (higher zinc tha today) SL oil for who-know-how-many-years...and were still oily, including an ancient 40 horse Bug motor, I have to think maybe they parked that engine while it was still full of combustion acids from start-up. Then it sat...and sat...and sat.

I'm just guessing.
(I hate putting and car away luke warm, unless I know I'm going to drive it up to something like really warm again real soon.)

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hambone
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Post by hambone » Tue May 04, 2010 7:22 am

Thanks for that article ya damn dirty Hippie. It answers my question.
http://greencascadia.blogspot.com
http://pdxvolksfolks.blogspot.com
it balances on your head just like a mattress balances on a bottle of wine
your brand new leopard skin pillbox hat

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Hippie
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Post by Hippie » Tue May 04, 2010 9:29 am

hambone wrote:Thanks for that article ya damn dirty Hippie. It answers my question.
You're welcome, you filthy pig-(bone)!

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hambone
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Post by hambone » Tue May 04, 2010 9:48 am

=D>
http://greencascadia.blogspot.com
http://pdxvolksfolks.blogspot.com
it balances on your head just like a mattress balances on a bottle of wine
your brand new leopard skin pillbox hat

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Hippie
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Post by Hippie » Fri Jun 18, 2010 2:43 pm

Anybody using this?

Image

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chitwnvw
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Post by chitwnvw » Fri Jun 18, 2010 7:32 pm

Do you have some? If so you are a serious collector.

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Hippie
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Post by Hippie » Sat Jun 19, 2010 9:36 am

I wish

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chitwnvw
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Post by chitwnvw » Sat Jun 19, 2010 1:01 pm

Shoot I thought you were cool for a second there.

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Hippie
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Post by Hippie » Sat Jun 19, 2010 2:46 pm

I get that a lot

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