15w 40 to thick?

[Shannow]

Agreed...I've never pulled apart a "dry" engine.

First few seconds, there is still enough oil around (and quite thick) to keep parts separated for a good while.

The Esso videos of a 15W-40 taking minutes are demonstrative of a misapplied oil at very low temperatures, not that the 15W-40 is "too thick" in every application.

 

[edhackett]

Originally Posted By: dnewton3

All parts, both pressure-fed and non-pressure-fed, ride on a film of oxidized lube called a tribo-chemical barrier. That film barrier is ALWAYS present and actually grows and thickens with age. The only time this film is undesirably altered is the front end of an OCI where the anti-agglomerate and detergent package is fresh and actually destroys that barrier, and it has to build back up again.


Dave, please stop posting this, as it is wrong. The Fujita reference in the introduction to the SAE paper saying the dispersant completely removed the anti-wear layer was a lab test using non fully formulated oils. The film removed by adding a dispersant was formed by the base oil and ZDDP only.

Please read the text accompanying Figure 4. They quote the same Fujita article saying that the film formed by a fully formulated oils was not removed. They also say that they found the film to be intact after two flushes of fresh oil in their study. Fully formulated oil does not remove the anti-wear layer put in place by a fully formulated oil.

Ed

 

[KCJeep]

Originally Posted By: dnewton3
Looking over the data in my UOA files, I cannot find any reason to believe that minor grade shifts (i.e. 5w-30 to 5w-20) will result in any tangible difference in wear.


You may find it interesting that the one engine I track diligently, the Jeep 4.0, most indeed does show higher wear numbers if oil gets much below a 30 grade. But it's not the "iron" number that everybody focuses on, it's the aluminum that skyrockets, usually 3 to 4 times as high as normal for a 30 grade.

I consider the 4.0 somewhat unique in that regard and agree it'd be near impossible to tell which is which (5w20 / 5w30) on wear numbers alone in most engines.

 

[jim78]

Sorry so late guys got side tracked. that Turbo guy has everybody up in arms.what impressive techno language.look people it's not that hard to concept thick oil dosenot pump well.

 

[jim78]

Oh and u still did not answer my question. keep on looking for it on the internet for it with all those big fancy words you use u should find it. By the way, Berings are not the first thing to were out on an engine so keep looking.

 

[Clevy]

Originally Posted By: jim78
Oh and u still did not answer my question. keep on looking for it on the internet for it with all those big fancy words you use u should find it. By the way, Berings are not the first thing to were out on an engine so keep looking.



What?

 

[KCJeep]

Very endearing...