Engine start up wear question.......

[mechtech2]

Unless the engine was sitting for a LONG time, cylinder/ring wear is not a startup problem.
Bearings and possibly cams can be oil starved at start up.
But once again, there is oil left on them from previously running, and it is not a problem with a good engine.
That's why engines last 2-300,000 miles or more.

 

[Gary in Sandy Eggo]

20 Cst provides good bearing and cam protection, and sufficient flow past bearings to provide excellent cylinder wall protection. 20 Cst is near the top end of SAE-50 oil at 100C (full operating temperature). At anything less than full operating temperature, progressively thinner rated oils will also provide 20 Cst.

Most engines require 20-30 minutes for the oil to reach full operating temperature. Consequently, if your driving habits are to do frequent trips of less than 30 minutes duration, you're better off using a light multi-grade as you'll have more than enough metal separation because the cooler oil will have a much higher viscosity than will the thicker oil at operating temperature.

OTOH, if your driving habits consist of 100+ miles for every cold start, you'd end up with better engine life with a mono-grade SAE-30, -40 or -50 depending on what the ambient temperatures are. (Ever wonder why big radial aircraft engines specify SAE-50 to SAE-70 monograde oils and forbid the use of multi-grade oils?)

Automobile manufacturers are recommending lighter and lighter oils because they DO result in better mileage with adequate protection at sub-operating temperatures, because they know that most car trips never see full operating temperatures.

 

[rg200amp]

Originally Posted By: ekpolk
Originally Posted By: rg200amp
I use redline 5w20, so i guess i am coverd all around, anyway at start up the oil is not at 20wt or 30wt, its at the smaller number. i use 5w20, so the 5 will flow very quickily.

This statement reflects one of the greatest misconceptions about the SAE grading scheme. The W part of the rating is NOT a viscosity range like the "hot" part of the rating is. It simply reflects whether the oil has passed certain tests that generally assess the oil's performance in cold situations. You could say it has some relation to viscosity, but it's not a vis rating at all. It is quite possible, for example to have a 0w rated oil that's actually thicker at a given "cold" temp than certain 5w oils are. GC, for example is one oil that's thicker than many 5w oils, but because of its ability to remain liquid and pumpable at very low temps, it qualifies for the 0w rating, while many 5w oils, especially dinos are thinner in vis, but solidify and become unpumpable at higher temps, and therefore don't qualify for the 0w rating. Clear as mud?



Yes, but as a basic rule of thumb it works. a 0w, is going to be thinner than a 10w, a 10w is going to be thinner than a 20w, a 20w is thinner than a 75w, ECT. . . . . .

There are allways little exceptions.

 

[HARTZSKY]

I remember buying 'Slick 50' back in the early nineties to combat cold start up wear. Did it work? I have no idea, and the car is long gone. Heck, I paid $50 for it, you can get it at Wal-mart these days for $11.

 

[Mamala Bay]

Yes, but as a basic rule of thumb it works. a 0w, is going to be thinner than a 10w, a 10w is going to be thinner than a 20w, a 20w is thinner than a 75w, ECT. . . . . .

There are allways little exceptions. [/quote]


Well the W meaning winter should be the cranking ability in cold temp. So a 0w30 should be easier than a 10w30. Could be thinner or thicker. A 20wt should be easier than a 30wt. This is more pronounce when temp becomes colder. But if you're in ideal temp or at 95 degree it becomes less pronounce in cranking ability difficulty. So a 30w cranks up with no problem at 95 degrees. Is it the same as a 5w-20 cranking up at 20 degrees.

 

[rg200amp]

Originally Posted By: Mamala Bay


Yes, but as a basic rule of thumb it works. a 0w, is going to be thinner than a 10w, a 10w is going to be thinner than a 20w, a 20w is thinner than a 75w, ECT. . . . . .

There are allways little exceptions.



Well the W meaning winter should be the cranking ability in cold temp. So a 0w30 should be easier than a 10w30. Could be thinner or thicker. A 20wt should be easier than a 30wt. This is more pronounce when temp becomes colder. But if you're in ideal temp or at 95 degree it becomes less pronounce in cranking ability difficulty. So a 30w cranks up with no problem at 95 degrees. Is it the same as a 5w-20 cranking up at 20 degrees. [/quote]

I am saying this:

go to auto store, pick up a quart of 0w30, 5 w30, and 10w30 same brand oil, shake the bottle. the smaller the w number, the thinner it is at room temp.

thinner at room temp=easy to flow. I live in Philadelphia, not the artic. I am just use my example as a average, not exact science.

all I know is a 0w30 at room temp is thinner than a 10w30.

yes the smaller number applies for cold flow, but in 70 degree weather, there is a thickness difference

 

[demarpaint]

Cold meaning the first start in the morning or after sitting for an extended period of time, a 0W is going to flow faster than a 5W or a 10W no matter what the outside temperature is. Even at 95* F a 0w will flow faster than a 5W. When hot its the second number that comes into play, and if we split hairs some brands are thinner or thicker in the same grade.

For the first start of the day or after sitting a while a 0W should give the best start-up protection.

HTH,
Frank D

 

[rg200amp]

Originally Posted By: demarpaint
Cold meaning the first start in the morning or after sitting for an extended period of time, a 0W is going to flow faster than a 5W or a 10W no matter what the outside temperature is. Even at 95* F a 0w will flow faster than a 5W. When hot its the second number that comes into play, and if we split hairs some brands are thinner or thicker in the same grade.

For the first start of the day or after sitting a while a 0W should give the best start-up protection.

HTH,
Frank D


Exactly

 

[slalom44]

I installed a prelube pump on my car 5 years ago along with an Amsoil bypass filter because of my concerns about startup wear. This is especially true with the Amsoil BMK-13 bypass filter, since I would expect oil starvation to be greater at startup. My used oil analysis look great, but not much different than if I just had a bypass filter without a prelube pump. Since I'm not measuring particle size, I really don't know how much I'm truly helping with the prelube pump.

But I will continue to use it, since it's installed and working great. I always have full pressure at startup (with Amsoil 0w30 oil). I may never know how much this pump reduces engine wear, but I think of it as cheap insurance.

Latest UOA with bypass & prelube pump

 

[bluesubie]

This thread has some good comparisons at various temps resulting from plugging the 100C and 40C numbers into a viscosity calculator.

-Dennis

 

[Bryanccfshr]

Originally Posted By: rg200amp
Originally Posted By: demarpaint
Cold meaning the first start in the morning or after sitting for an extended period of time, a 0W is going to flow faster than a 5W or a 10W no matter what the outside temperature is. Even at 95* F a 0w will flow faster than a 5W. When hot its the second number that comes into play, and if we split hairs some brands are thinner or thicker in the same grade.

For the first start of the day or after sitting a while a 0W should give the best start-up protection.

HTH,
Frank D


Exactly




No, Not exactly.

To understand this you really need to understand how the SAE J300 ratings are measured. There are a few 0w30 oils that will be thicker at a 95° start up temp than most 5w30's for example. You need to look at the viscosity curves and see where they correspond to your start up temp to understand that the oil with the lowest viscosity at start up for your situation is not the same as the one for a -35 situation.

To state that a 0w is thinner than a 5w which is thinner than a 10w at start up temps is incorrect. Those are cold cranking ratings based on temperatures most of us do not experience.

 

[rg200amp]

Originally Posted By: Bryanccfshr
Originally Posted By: rg200amp
Originally Posted By: demarpaint
Cold meaning the first start in the morning or after sitting for an extended period of time, a 0W is going to flow faster than a 5W or a 10W no matter what the outside temperature is. Even at 95* F a 0w will flow faster than a 5W. When hot its the second number that comes into play, and if we split hairs some brands are thinner or thicker in the same grade.

For the first start of the day or after sitting a while a 0W should give the best start-up protection.

HTH,
Frank D


Exactly




No, Not exactly.

To understand this you really need to understand how the SAE J300 ratings are measured. There are a few 0w30 oils that will be thicker at a 95° start up temp than most 5w30's for example. You need to look at the viscosity curves and see where they correspond to your start up temp to understand that the oil with the lowest viscosity at start up for your situation is not the same as the one for a -35 situation.

To state that a 0w is thinner than a 5w which is thinner than a 10w at start up temps is incorrect. Those are cold cranking ratings based on temperatures most of us do not experience.



Go to auto store, shake bottle of 0w30, and 10w30 (SAME BRAND). 0w is thinner.
its not rocket science

 

[Gary Allan]

Quote:
Cold meaning the first start in the morning or after sitting for an extended period of time, a 0W is going to flow faster than a 5W or a 10W no matter what the outside temperature is. Even at 95* F a 0w will flow faster than a 5W. When hot its the second number that comes into play, and if we split hairs some brands are thinner or thicker in the same grade.


Well, I think that we need to view this as "easier" and not faster. Without other conditions altering the view, they all flow the same in a pumped situation.

 

[demarpaint]

Originally Posted By: Gary Allan
Quote:
Cold meaning the first start in the morning or after sitting for an extended period of time, a 0W is going to flow faster than a 5W or a 10W no matter what the outside temperature is. Even at 95* F a 0w will flow faster than a 5W. When hot its the second number that comes into play, and if we split hairs some brands are thinner or thicker in the same grade.


Well, I think that we need to view this as "easier" and not faster. Without other conditions altering the view, they all flow the same in a pumped situation.


Thanks for the correction. I always observed 5W-xx vs 10W-xx building pressure faster when cold being pumped through my pre-luber. In some instances building pressure in half the time, so I took for granted that it was pumping/flowing faster and easier than the 10W-xx. Taking it a step further I came to the conclusion it was being pumped with the oil pump faster as well. Just my observations nothing scientific.

I also observed synthetic vs. dino thru the pre-luber and the synthetic builds pressure faster, 10W-xx syn vs. 10W-xx dino.

Frank D

 

[Bryanccfshr]

Ahhh the all telling "shake test" Who needs science and facts anyway?

 

[Gary Allan]

Quote:
Taking it a step further I came to the conclusion it was being pumped with the oil pump faster as well. Just my observations nothing scientific.

I also observed synthetic vs. dino thru the pre-luber and the synthetic builds pressure faster, 10W-xx syn vs. 10W-xx dino.


Well, I'm sure your observations are correct and have merit. When people see slower "time to pressure" it's surely related to the cold viscosity, but it's more due to losses in the pump due to the relief action from not being able to move a heavy static mass of oil from zero to "whatever" rate of flow. In the case of your perluber ..it either has its own internal relief ..or has to be operating slower with heavier fluids (due to cold viscosity).

I'm just trying to communicate the difference between "it flows faster" as opposed to "it's quicker to reach pressure due to being easier to pump". It's a distinction that many miss. For example ..even if you had 100F fluid or 200F fluid ..if there was no relief action, they would both reach pressure (albeit different pressures) at about the same time ..although maybe with a slightly inverted view. That is the thinner oil may take just a bit longer to reach terminal pressure just due to easier throughput while the higher visc oil will have more accumulated "back pressure" just due to it's higher friction in the passages and lower ability to shear easily.

 

[demarpaint]

Clear as mud!

Frank D

 

[Gary Allan]

Originally Posted By: demarpaint
Clear as mud!

Frank D

Yeah ...I get that a lot.

A friend kept telling me, "Simplify- simplify - simplify" ..but when I do that, then I get every other swinging member pointing out every over simplified nuance that exists under the sun.

..and people wonder why I have long posts

 

[Doug Hillary]

Hi,
Gary - A factor often misunderstood is flow! Pressure of course is the resistance to flow. And we all know that automotive oil pumps are of the constant flow variety. (Porsche's latest DI engines have an electrically regulated oil pump and four scavange pumps)

Many engines today have very complex lubrication systems and quite sophisticated components that depend on the balance of both

For me intial flow is a critical point and the lubricant that provides the best linear flow is my choice. Too much time in by-pass is usually counterproductive in wear reduction

Gary, I believe in the KISS approach too - you will always have critics - that is why I don't contribute much on Technical matters - making complex matters simple is often very difficult IMHE

 

[Gary Allan]

Hi, Doug. I think that flow is misunderstood ..or mis-stated due to how it is counter to most things that we experience daily.

You do bring up something interesting (you always bring something good to the table of discussions) is how our conventional limitations to lubricant flow are being altered. That is, where normal physics limits certain things ..leave it to the Germans (who probably sit at their CAD terminals dwelling on nothing more than complicating things

) where they'll merely bypass a few universal constants (change conventions on you). The Japanese are also employing "displacement on demand" oil pumps ..but in mechanical versions. I don't understand the intimate nuances of these things (would love a digestible technical paper) ..but ..that's for the more advanced user anyway

Basically, people aren't used to a flow dictating equation in view. Flow is usually the result of applied pressure through a given resistance. It's very hard to alter that view.