Noak and wear

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Originally Posted By: il_signore97
Originally Posted By: OVERKILL
But wouldn't this be similar to Ford freezing an engine solid and then running it WOT? I mean 5w-30 at -20C is going to be heavier than a 50wt race oil at 30C.

I agree. Many manufacturers do such testing with their engines / vehicles. I've been to the GM headquarters in Detroit several times when I used to be more involved with the SAE, and they once gave us a presentation on cold weather testing. And like Overkill said, they deep freeze vehicles overnight, sometimes to as low as -40C, jump in, and go. .


For the readers, they are talking about Car and Driver magazine Article page
 
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Originally Posted By: CATERHAM
It has everything to do with the oil.
Yes it's preferable to have the engine up to temperature before extracting full power but you can run an engine at full power stone cold with a very light qualifying 2wt or 5wt race oil if you're so inclined. Try it with a 50 grade and I guarantee you'll break the engine.
I've seen it happen at the track a number of times on a cold day with a 50 grade race oil.
The point is most drivers who choose to run these 2-3 grade heavier than spec' oils have no clue what their oil temp's are and that's how they get into trouble.

But even if you do get your oil temp's into the
normal range before using maximum rev's if you're deep into by-pass your oil temp's can sky rocket and that simply isn't a good plan for long engine life.
The reason anyone runs a heavier than spec' oil in an engine in otherwise good shape, is under the assumption of greater engine protection.
Running in by-pass defeats that purpose entirely and since the by-pass point is usually well above the optimum operational viscosity level, it's a sure fire indication that the oil is simply way too thick, potentially dangerously so.



You seem to be conveying the impression that oil alone is important on cold starts.
Not so. The entire engine should be warmed to operating temperature before it's put to the lash, since operating clearances of all of the moving parts are planned with the thermal expansion that follows warm-up in mind.
Head gaskets failures on an engine beat on hard from cold are known to happen as well, particularly with those engines using alloy heads on iron blocks.
To the extent that it is the oil, you know very well that it takes some heat to get some of the additives active without regard to the viscosity of the oil.
 
Originally Posted By: fdcg27
Originally Posted By: CATERHAM
It has everything to do with the oil.
Yes it's preferable to have the engine up to temperature before extracting full power but you can run an engine at full power stone cold with a very light qualifying 2wt or 5wt race oil if you're so inclined. Try it with a 50 grade and I guarantee you'll break the engine.
I've seen it happen at the track a number of times on a cold day with a 50 grade race oil.
The point is most drivers who choose to run these 2-3 grade heavier than spec' oils have no clue what their oil temp's are and that's how they get into trouble.

But even if you do get your oil temp's into the
normal range before using maximum rev's if you're deep into by-pass your oil temp's can sky rocket and that simply isn't a good plan for long engine life.
The reason anyone runs a heavier than spec' oil in an engine in otherwise good shape, is under the assumption of greater engine protection.
Running in by-pass defeats that purpose entirely and since the by-pass point is usually well above the optimum operational viscosity level, it's a sure fire indication that the oil is simply way too thick, potentially dangerously so.



You seem to be conveying the impression that oil alone is important on cold starts.
Not so. The entire engine should be warmed to operating temperature before it's put to the lash, since operating clearances of all of the moving parts are planned with the thermal expansion that follows warm-up in mind.
Head gaskets failures on an engine beat on hard from cold are known to happen as well, particularly with those engines using alloy heads on iron blocks.
To the extent that it is the oil, you know very well that it takes some heat to get some of the additives active without regard to the viscosity of the oil.



thumbsup2.gif


I drive like a grandma in an old age home until I'm sure the engine is fully warm in my vehicles unless otherwise necessary. It's overkill of the greatest kind given the reliability of today's engines, but I want the absolute lowest wear possible to make me feel warm and fuzzy inside
wink.gif
 
I avoid using much power or many revs until I think the engine has reached a reasonable temperature.
Necessary or not?
I don't really know, but I try to avoid abusing the machinery.
 
Originally Posted By: fdcg27
I avoid using much power or many revs until I think the engine has reached a reasonable temperature.
Necessary or not?
I don't really know, but I try to avoid abusing the machinery.


Same here & I have been doing that for about 25 years.
shocked2.gif


Never had one single engine issue. Ever.
thumbsup2.gif
 
Originally Posted By: fdcg27

For any pressure lubrication system I've ever heard of, all of the important bits are fed by a positive displacement pump.
This means that the same amount of oil is delivered at any give number of revs without regard to its viscosity.

That's also not true.
Viscosity affects the rate of oil flow through an engine even when the oil pump is not in by-pass. Yes oil pumps are of the positive displacement type but the system is closed so there are slippage, cavitation, intake pipe restrictions, etc that affect how much oil will be pumped. Lower viscosity oil flows less restricted through an engine, as a result the system back pressure is correspondingly lower.

The lubrication tenet regarding viscosity is, "light as possible, as thick as necessary."
It's not, "thick as possible as light as necessary", as some seem to think.
 
Originally Posted By: CATERHAM
That's also not true.
Viscosity affects the rate of oil flow through an engine even when the oil pump is not in by-pass. Yes oil pumps are of the positive displacement type but the system is closed so there are slippage, cavitation, intake pipe restrictions, etc that affect how much oil will be pumped. Lower viscosity oil flows less restricted through an engine, as a result the system back pressure is correspondingly lower.


Yes, but you always seem to forget the little fact that the change in flow is usually in the order of few percentage points in the SYSTEM where the change in head pressure can be several TIMES higher. You know, to accommodate several hundred percentage points for the change in oil viscosity for extreme cold to operating temp. Hence, the use of positive displacement pumps. For all intents and purposes the flow can safely be assumed to be the same.
Yet, you continue to bring this very minor change in flow volume as some major positive attribute to use light oils. This minor change in flow is simply irrelevant.
Below is a good read comparing positive and centrifugal pumps.


http://www.pumpschool.com/intro/pd vs centrif.pdf
 
Originally Posted By: KrisZ
Originally Posted By: CATERHAM
That's also not true.
Viscosity affects the rate of oil flow through an engine even when the oil pump is not in by-pass. Yes oil pumps are of the positive displacement type but the system is closed so there are slippage, cavitation, intake pipe restrictions, etc that affect how much oil will be pumped. Lower viscosity oil flows less restricted through an engine, as a result the system back pressure is correspondingly lower.


Yes, but you always seem to forget the little fact that the change in flow is usually in the order of few percentage points in the SYSTEM where the change in head pressure can be several TIMES higher. You know, to accommodate several hundred percentage points for the change in oil viscosity for extreme cold to operating temp. Hence, the use of positive displacement pumps. For all intents and purposes the flow can safely be assumed to be the same.
Yet, you continue to bring this very minor change in flow volume as some major positive attribute to use light oils. This minor change in flow is simply irrelevant.
Below is a good read comparing positive and centrifugal pumps.


http://www.pumpschool.com/intro/pd vs centrif.pdf


And of course the point Shannow has made in the past about this which is that thinner oils, in a gear-style positive displacement pump, will exhibit more leakage.
 
Flow volume vs different viscosities would be incredibly easy to test and I'm sure it's been tested at some point. If the results were anything other than it doesn't really matter the tests would be posted here daily.
 
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Originally Posted By: KrisZ
Originally Posted By: CATERHAM
That's also not true.
Viscosity affects the rate of oil flow through an engine even when the oil pump is not in by-pass. Yes oil pumps are of the positive displacement type but the system is closed so there are slippage, cavitation, intake pipe restrictions, etc that affect how much oil will be pumped. Lower viscosity oil flows less restricted through an engine, as a result the system back pressure is correspondingly lower.


Yes, but you always seem to forget the little fact that the change in flow is usually in the order of few percentage points in the SYSTEM where the change in head pressure can be several TIMES higher. You know, to accommodate several hundred percentage points for the change in oil viscosity for extreme cold to operating temp. Hence, the use of positive displacement pumps. For all intents and purposes the flow can safely be assumed to be the same.
Yet, you continue to bring this very minor change in flow volume as some major positive attribute to use light oils. This minor change in flow is simply irrelevant.
Below is a good read comparing positive and centrifugal pumps.


http://www.pumpschool.com/intro/pd vs centrif.pdf

That's a general discussion of pump types not how they function in an automotive closed system.
We've hashed this out before in other threads and the conclusion is that lighter oil flows faster than heavier oil. If the system back-pressure is reduced significantly, say 30 psi with a lighter oil, I posit that the increased flow will be considerably more than "a few percentage points".
 
Originally Posted By: CATERHAM
We've hashed this out before in other threads and the conclusion is that lighter oil flows faster than heavier oil. If the system back-pressure is reduced significantly, say 30 psi with a lighter oil, I posit that the increased flow will be considerably more than "a few percentage points".


Invariably YOU conclude that thin oil has a greater flow rate, in spite of overwhelming evidence and actual science (not feel) from the manufacturers of pumps and systems.

Originally Posted By: CATERHAM
slippage

While generally a term used in non-positive displacement pumps, I "feel" you are referring to internal leakage, which always is higher with thinner lubricants (look up our previous discussions for more details)

Originally Posted By: CATERHAM
cavitation

Again, it's a term that's misapplied to positive displacement pumps, but in reality is a symptom of

Originally Posted By: CATERHAM
intake pipe restrictions


Leading to inadequate NPSH on the pump, and incomplete filling.

Thin oil isn't "better" at it, any oil that's not grossly misapplied is perfectly fine at it.

In any engine at operating temperature, a 12cst oil will have greater delivery volume than a 6cst...it's simple science, which is easily verifiable to take the "feel" out of the discussion.
 
Originally Posted By: Shannow
Originally Posted By: CATERHAM
We've hashed this out before in other threads and the conclusion is that lighter oil flows faster than heavier oil. If the system back-pressure is reduced significantly, say 30 psi with a lighter oil, I posit that the increased flow will be considerably more than "a few percentage points".


Invariably YOU conclude that thin oil has a greater flow rate, in spite of overwhelming evidence and actual science (not feel) from the manufacturers of pumps and systems.

In any engine at operating temperature, a 12cst oil will have greater delivery volume than a 6cst...it's simple science, which is easily verifiable to take the "feel" out of the discussion.


I'm just blown away here. This is what makes me doubt you are an engineer or even employed in a technical position.

You can model an engine as a numbers of branches with fixed orifices or a single branch with one orifice. It doesn't matter.

Given the same pressure, a thicker fluid will flow more slowly through a given size orifice than a thinner fluid. End of story.

It's intuitive for me. And you and your followers are misleading everyone here and have been for some time.
 
Quote:
does a higher Noak number mean more engine wear?


Not directly. If the evaporates re-condense into oxidized/hydrolized deposits, the deposits may increase wear by it's own mode. If enough of the crankcase oil evaporates and is unrecoverable, the reduced crankcase fill may be subjected to more stress and can break down at an accelerated rate, possibly increasing wear by it's own mode. No direct correlation, though.

ps- the nook/cranny debate is killing me here
lol.gif
 
Originally Posted By: jrustles
Quote:
does a higher Noak number mean more engine wear?


Not directly. If the evaporates re-condense into oxidized/hydrolized deposits, the deposits may increase wear by it's own mode. If enough of the crankcase oil evaporates and is unrecoverable, the reduced crankcase fill may be subjected to more stress and can break down at an accelerated rate, possibly increasing wear by it's own mode. No direct correlation, though.

ps- the nook/cranny debate is killing me here
lol.gif



People worrying about noak and wear is hilarious.Do a engine tear down if you want to know how well an oil is working for your application and stop worrying about what noak is,unbelievable.
crazy2.gif
 
Originally Posted By: DragRace
[
People worrying about noak and wear is hilarious.Do a engine tear down if you want to know how well an oil is working for your application and stop worrying about what noak is,unbelievable.
crazy2.gif



It is interesting how everyone latches onto one parameter. I am sure I have always used mostly high NOACK oils. It is like reading MSDS sheets and guessing what is in the 95% of the product not mentioned.
 
Originally Posted By: turtlevette

I'm just blown away here. This is what makes me doubt you are an engineer or even employed in a technical position.

You can model an engine as a numbers of branches with fixed orifices or a single branch with one orifice. It doesn't matter.

Given the same pressure, a thicker fluid will flow more slowly through a given size orifice than a thinner fluid. End of story.

It's intuitive for me. And you and your followers are misleading everyone here and have been for some time.


Instead if boasting YOUR supposed credentials and questioning others, which by the way I never see Shannow mentioning his background at every opportunity he gets, maybe you should read up on what positive displacement pumps do and how they do it instead of making a fool of yourself and whatever education you might or might not have.
 
Since replacing the spec 5W-30 for 0W-40, I'm seeing LOWER pressure at all temperatures. The gauge never reads higher than ~60 psi which I assume is bypass pressure but it did that on the 30-grade too.
21.gif


Originally Posted By: turtlevette
Given the same pressure, a thicker fluid will flow more slowly through a given size orifice than a thinner fluid. End of story.
 
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