In thick vs thin don't forget the additives

[SteveSRT8]

Originally Posted By: A_Harman
Originally Posted By: turtlevette
The stuff Solara quoted is how lubrication works in a bearing. The cam and rings have different considerations and modes of lubrication.



You're dead wrong at the outset, turtlevette. The Stribeck curve is a general description of lubrication between sliding surfaces, whether they are planar or curved.


Interesting. It's so nice to have the members we do here...

 

[Shannow]

Originally Posted By: Solarent
In today's oils, great progress is being made on both sides of the bottom of the curve (representing the optimal viscosity) to reduce friction in these areas. On the boundary side (or left of the base of the curve) chemical additives such as friction modifiers, antiwear additives and ep components of engine oils which provide protection when viscosity alone is not enough. On the hydrodynamic side (or the right of the base of the curve) more stable viscosity properties of high index, lower viscosity base oils are reducing frictional drag. Today's oils are the sum of their parts not just one attribute or one component of the base or additive package. (Good base oils + High performing additives = Great Oil)


Exactly...with modern friction modifiers, in modern oils, the curve doesn't have the traditional uptick to the left, but gets more of a flat line, allowing OEMs to operate more in mixed lubrication modes in places.

eg.

http://www.threebond.co.jp/en/technical/technicalnews/pdf/tech09.pdf

Table 6. for the effective curve with friction modifiers.

 

[turtlevette]

Originally Posted By: A_Harman

You're dead wrong at the outset, turtlevette. The Stribeck curve is a general description of lubrication between sliding surfaces, whether they are planar or curved.



Surely you understand there is a difference. The ring scrapes oil. The bearing traps oil in a wedge.

I'm a bit disappointed being you are a Corvette owner and all.

Some people just don't have an intuitive feel for this stuff. You know. A mechanical aptitude.

 

[Brent_G]

Originally Posted By: turtlevette
Originally Posted By: A_Harman

You're dead wrong at the outset, turtlevette. The Stribeck curve is a general description of lubrication between sliding surfaces, whether they are planar or curved.



Surely you understand there is a difference. The ring scrapes oil. The bearing traps oil in a wedge.

I'm a bit disappointed being you are a Corvette owner and all.

Some people just don't have an intuitive feel for this stuff. You know. A mechanical aptitude.


The Stribeck-Hersey curve by definition is used to categorize the friction properties between two sliding surfaces.

What you "think" doesn't change facts.

 

[MolaKule]

Originally Posted By: turtlevette



Surely you understand there is a difference. The ring scrapes oil. The bearing traps oil in a wedge.

I'm a bit disappointed being you are a Corvette owner and all.

Some people just don't have an intuitive feel for this stuff. You know. A mechanical aptitude.


And apparently you don't either.

You really need to study John B Haywoods text on IC engines, specifically Pages 731 to 734, where the oil film thickness varies from 0.25 um to 7 um, depending on load.

Figure 13-18 on page 731 describes the pressure profile of the compression ring on the oil film and it is a vertical wedge.

 

[Solarent]

Originally Posted By: Shannow
Exactly...with modern friction modifiers, in modern oils, the curve doesn't have the traditional uptick to the left, but gets more of a flat line, allowing OEMs to operate more in mixed lubrication modes in places.

eg.

http://www.threebond.co.jp/en/technical/technicalnews/pdf/tech09.pdf

Table 6. for the effective curve with friction modifiers.


Wow that's an old example! Still applicable but I was still very young when it came out - and not interested in lubricants yet.

Here's something a little more recent Link
See slides 17-19.

(I posted this link in the Science and Technology forum shortly after I attended... I can also provide links to the event recording if you are interested).

 

[Shannow]

Originally Posted By: MolaKule
You really need to study John B Haywoods text on IC engines, specifically Pages 731 to 734, where the oil film thickness varies from 0.25 um to 7 um, depending on load.


awesome book...cost me a week's pay back in the day, and still my most thumbed text.

 

[MolaKule]

Originally Posted By: Solarent
Originally Posted By: Shannow
Exactly...with modern friction modifiers, in modern oils, the curve doesn't have the traditional uptick to the left, but gets more of a flat line, allowing OEMs to operate more in mixed lubrication modes in places.

eg.

http://www.threebond.co.jp/en/technical/technicalnews/pdf/tech09.pdf

Table 6. for the effective curve with friction modifiers.


Wow that's an old example! Still applicable but I was still very young when it came out - and not interested in lubricants yet.

Here's something a little more recent Link
See slides 17-19.

(I posted this link in the Science and Technology forum shortly after I attended... I can also provide links to the event recording if you are interested).


Yep, very familiar with Croda's presentations, but don't use Croda's FMs, I use Polyermic FMs from other companies, which I referenced in previous threads when discussing ashless FMs.

 

[turtlevette]

Originally Posted By: MolaKule
[And apparently you don't either.

You really need to study John B Haywoods text on IC engines, specifically Pages 731 to 734, where the oil film thickness varies from 0.25 um to 7 um, depending on load.

Figure 13-18 on page 731 describes the pressure profile of the compression ring on the oil film and it is a vertical wedge.


I should think it's a much smaller wedge. So you're going to campaign that ring lubrication, bearing lubrication and cam lubrication should all be modeled the exact same way. You're the guy that told me to start a new thread on oil technology then gave me evasive non committal answers? Right?

 

[MolaKule]

Originally Posted By: turtlevette
Originally Posted By: MolaKule
[And apparently you don't either.

You really need to study John B Haywoods text on IC engines, specifically Pages 731 to 734, where the oil film thickness varies from 0.25 um to 7 um, depending on load.

Figure 13-18 on page 731 describes the pressure profile of the compression ring on the oil film and it is a vertical wedge.


I should think it's a much smaller wedge. So you're going to campaign that ring lubrication, bearing lubrication and cam lubrication should all be modeled the exact same way. You're the guy that told me to start a new thread on oil technology then gave me evasive non committal answers? Right?




I am presenting data from a text that takes actual pressure measurements.

Quote:
You're the guy that told me to start a new thread on oil technology then gave me evasive non committal answers?


I gave answers commensurate with your question.

You are good at obfuscating the topic by throwing in non-related comments.

 

[Solarent]

Hey Mola - are you saying I shouldn't use Croda FM's or that you don't use them.

For the record we've only just started experimenting with some samples. But we have played with lots of boundary lubricants over the years from a wide range of sources.

 

[MolaKule]

Originally Posted By: Solarent
Hey Mola - are you saying I shouldn't use Croda FM's or that you don't use them.

Not at all, good products.

Quote:
For the record we've only just started experimenting with some samples. But we have played with lots of boundary lubricants over the years from a wide range of sources.


I have been using various forms of polymeric FMs for three years now.

 

[turtlevette]

Originally Posted By: MolaKule

You are good at obfuscating the topic by throwing in non-related comments.


I throw out questions and challenge people who apparently aren't used to being questioned and challenged but worshiped. I guess I'm crazy.

The old [censored] cast iron rings I put on my SBC don't looked tapered. Maybe its so slight I just couldn't tell. I've seen the advanced stuff used in drag racing like holes drilled in the piston top to channel pressure to the back side of the ring to get extra ring pressure against the cylinder wall on the power stroke.

 

[Brent_G]

Originally Posted By: turtlevette
Originally Posted By: MolaKule

You are good at obfuscating the topic by throwing in non-related comments.


I throw out questions and challenge people who apparently aren't used to being questioned and challenged but worshiped. I guess I'm crazy.

The old [censored] cast iron rings I put on my SBC don't looked tapered. Maybe its so slight I just couldn't tell. I've seen the advanced stuff used in drag racing like holes drilled in the piston top to channel pressure to the back side of the ring to get extra ring pressure against the cylinder wall on the power stroke.





The difference is you don't throw out questions, you say blanket statements and when anybody questions you they are instantly wrong and you are right. I wouldn't say anybody here is worshiped but some are well respected.

 

[Solarent]

Originally Posted By: turtlevette
I throw out questions and challenge people who apparently aren't used to being questioned and challenged but worshiped. I guess I'm crazy.

The old [censored] cast iron rings I put on my SBC don't looked tapered. Maybe its so slight I just couldn't tell. I've seen the advanced stuff used in drag racing like holes drilled in the piston top to channel pressure to the back side of the ring to get extra ring pressure against the cylinder wall on the power stroke.


I don't mind the questions or the discussion that results. But this is why I started this thread: to review some of the basic principles of lubrication as it relates to the thick vs thin debate.

Many members here are poorly informed or don't seek out the data from respected sources. In many cases this is not their fault as it can be hard to see the forest through the trees. But then it is sometimes combined with personal anecdotes and name-calling. IMO this obfuscates the discussion at hand, and doesn't add to the educative theme of what this forum is all about. Incidentally this is also why I started a separate thread - so it didn't hijack the other discussions.

Personal anecdotes and experiences have their place. But lets not get them confused with established studies and proven principles in the field of tribology.

 

[Oil Changer]

turtlevette,

This site is down to about four guys that visit regularly and actually know what they are talking about. You are arguing with three of them. It has nothing to do with worship. Heck, it has little to do with respect either. You need to learn whom it is you are trying to argue with and pick your battles.

 

[Lex94]

Worshiping is for the childish and weak...There are some here who do swim in the adult pool of mass/energy physical reality.

Thanks for the link, Solarent. I will just stick to "old man" conventional 10w30.

 

[novadude]

Originally Posted By: turtlevette
Originally Posted By: jrustles
Key point here. And as mentioned in the past few days, bearing design is changing to accommodate hydrodynamic lubrication using the thinner oils, but not drastically.



From what I'm reading it is pretty drastic. Going from a trimetal design with lead, zinc and copper to a silicon impregnated aluminum.

Now I wonder if we will have updated replacements for old stuff like my frist gen small block chevy.


What do you mean? Al-Si bi-metal bearings? They've been on the market for SBCs for several years now. I just used a set of King SI bearings in a 1969 350 I built last summer. They are actually cheaper than a traditional Clevite 77 tri-metal. Federal-Mogul has them, King has them, etc. Pretty common Gen 1 SBC rebuild parts.

http://kingbearings.com/files/Engine_Bearing_Materials.pdf

 

[turtlevette]

Originally Posted By: Oil Changer
turtlevette,

This site is down to about four guys that visit regularly and actually know what they are talking about. You are arguing with three of them. It has nothing to do with worship. Heck, it has little to do with respect either. You need to learn whom it is you are trying to argue with and pick your battles.


Yes, thank you. please provide me with a list of those which whom I should pay homage.

Oh, wait. I forgot. I don't kiss backsides.

 

[Oil Changer]

You wouldn't pick a fist fight with Mike Tyson. That's what you're doing here.

Originally Posted By: turtlevette
Originally Posted By: Oil Changer
turtlevette,

This site is down to about four guys that visit regularly and actually know what they are talking about. You are arguing with three of them. It has nothing to do with worship. Heck, it has little to do with respect either. You need to learn whom it is you are trying to argue with and pick your battles.


Yes, thank you. please provide me with a list of those which whom I should pay homage.

Oh, wait. I forgot. I don't kiss backsides.