Viscosity change vs oil temps

[MilesO]

Caterham,
I can work with info in that form. Which link off of Gary's link did you use to get that info ? Also where can I find the specific data for a given oil?

Thanks

 

[MilesO]

Thanks MechTech2.

Is this a characteristic of all motor oils ?

 

[Gary Allan]

Imagine a line on a graph that passes through two points. For motor oil they use the viscosity at 40C and 100C to determine the Viscosity index. Most oil blenders (except Castrol) usually provide these numbers.

What brand of oil do you have interest in?

..but you fibbed to us. You said you would tell us the reason for the questions.

 

[MilesO]

The oils I'm interested in are Mobil 1 0w50, Mystik 5w50, and Kendall GT1 10-40 unless they make a 50.

The purpose of this exercise is related to the possible necessity of running a serious cam profile at rpms not friendly to hyd lifters. The 50 wt may allow that but at an increase in pumping losses. Knowing where specific oil vis is at a given operating temp compared to known temps will help in initial lubricant comparison, then choice .

Have to leave again for a couple of hours ..

 

[Gary Allan]

Are you talking parasitic losses? The various weights you suggest are more alike when hot/warm. The difference in the power required to pump them gets less significant at/near/above the 100C mark ..or at any point really. The hotter it gets the more they resemble each other ..at least in the power to pump them.

On Mystics site I can't find a 5w-50. A 15w-50 and a SAE 50, yes.
Mobil doesn't make a 0w50 that I'm aware of.

http://www.mystiklubes.com/products_catalog.jsp#ENGINEOILS

 

[Ken2]

You guys are way off base.



A 5w30 has a dynamic viscosity at -30°C of no more than 6600 milliPascals. It has a kinematic viscosity at 100°C between 9.3 and 12.49 centiStokes. The other oil "weights" are shown on the chart. Note that weights with the "W" refer to the cold viscosity spec...0W, 5W, 10W, 15W, 20W. Weights without the "W" refer to the hot viscosity spec...20, 30, 40, 50, 60.

 

[MilesO]

I noticed that from the info off the link you provided .. at normal oil operating temps the line separation was indestinguishable. I want to enlarge that end of the graph and better decern the actual differences. I mayn need to include a monograde in 50 and 60 for more comparison info.

gotta go ...

 

[Gary Allan]

Quote:
A 5w30 has a dynamic viscosity at -30°C of no more than 6600 milliPascals.


That's it's cold performance characteristics in the cold crank simulator. It would be the same for all 5w's (limits) regardless of their hot visc designation. A 40 will still require more energy to pump than a 30 weight.

To not qualify that creates some imagined "Duuuuhh (imagine one finger in nose - other in ear) ..since I'm using a 5w-50 ..I'm getting all the ease that the 5w-20 guys do (drool - snort- belch) ..but getting the added protection for FREE!!! (cover one nostril and blow nose on the ground).

 

[fdcg27]

Gary, you know more about oil than I am ever likely to.
I want to raise a point, however.
What about the natural viscosity index of an oil's basestock?
Even a monograde 30W could (and sometimes does) qualify as a 10w30, absent any VIIs.

 

[Gary Allan]

In a synthetic, sure ..and I don't know all that much about oils. I spent a long time on filtration and picked up anything in regard to extended properties of oils via osmosis. I've never taken a physics or chemistry course. The whole Newtonian vs. non-Newtonian thing is what throws most of us for a loop because it uses irrational terms...or rather describes/quantifies irrational properties. People try to apply rational views to them.

The base stock of most 5w30 oils is in the 20 range.

 

[Audi Junkie]

Don't forget all the various oil grades that share the same W rating do not share the same cold cranking spec, just the temp itself is the same for the test. Also, the different grades are not the same in the cold in general. That is, a 5w-20 is far thinner than a 5w-50 for the cold-cranking test at -25f and at EVERY OTHER visc.

 

[MilesO]

This is the Kendall product I had in mind ..
http://www.conocophillipslubricants.com/documents/kendall/automotive_engine_oils/Ken%20GT-1%20High%20Performance%20MO%20(Ti)%20TDS%20Web.pdf

The Mystic product ..
http://docs.mystiklubes.com/msds_pi/M20073.pdf

The Mobil 1 product ..
http://www.mobil.com/USA-English/Lubes/PDS/NAUSENPVLMOMobil1_15W-50.asp
and
http://www.mobil.com/USA-English/Lubes/P...sApprovalsTitle

I have been using the Kendall product without issues in both flat tappet and roller engines. The new hyd lifter only rule is the reason for this search effort. 6500 rpm is upper limit.

 

[priler]

The oils I'm interested in are Mobil 1 0w50, Mystik 5w50, and Kendall GT1 10-40 unless they make a 50.

The purpose of this exercise is related to the possible necessity of running a serious cam profile at rpms not friendly to hyd lifters. The 50 wt may allow that but at an increase in pumping losses. Knowing where specific oil vis is at a given operating temp compared to known temps will help in initial lubricant comparison, then choice .


i'm not sure what you need since there isn't alot of info but it seems to me that your looking for something that falls within a 50wt and yet flows as easy as possible(for less drag).

if you like mobil 1,they do make a 5w-50 that may serve you better than the one's you listed.

mobil 1 5w-50
SM/SL/SJ/CF
ACEA A3/B3 A3/B4
MB 229.3,229.1
[email protected]
[email protected]
sulfated ash-1.3
Ph-1000
Zn-1100
FP-228C
TBN-11.8
VI-184
HT/HS-4.3

i don't know if the ZDDP levels are what you may need though.

generaly speaking,most of the time,it can only be found at ford dealerships. they stock it and recommend it for the baddest mustang ford makes.(i forget the model name)

believe it or not,there are other oils that fall into the 50wt that flow even easier and yet have a stronger film strength and HT/HS.(read my sig,but that's a MC oil)

i'm not sure anybody here knows what you need.there's not enough info.

 

[MilesO]

Thanks Priler, I am unsure what info would be most helpful to you and others to make informed suggestions. More engine build info, more application info, more operation info ?

The 5w-50 M1 info is appreciated, it is the one mentioned to me at PRI, its not on the M1 site.

A similar engine oil having lower pumping losses and increased film strength at 280 degrees ? Do you have one in mind ?

 

[Audi Junkie]

15w-40 HD?

 

[Gary Allan]

MilesO ..help me out here on your concerns of pumping losses. I'm assuming that you mean parasitic losses ..aka: the hp to pump the oil. At your proposed oil temps ..the difference between one of your suggested visc or the other are marginal. If any power advantage is what you're seeking, I think you're sweeping a very clean corner trying to scavenge gain.

I assume this engine is supposed to last more than 500 miles.

 

[MilesO]

Gary Allen, The requirement of hyd lifters only is reason for this search. Heavier wt oils at higher pressures reduce the compression of the lifter, allow higher rate springs, operate at higher rpm . Your parasitic losses are my pumping losses.

This engine is the mule for the next six months during the development under the new rules, the hyd lifter is the main challenge. More like 500 minutes .

I agree regarding your viscosity comment. After reading numerous spec sheets of 40-50 wt range oils I realize this approach to the lifter issue may be already be answered .

 

[MilesO]

Thanks for responding to my question . I have learned important lubrication knowledge from your replies .

 

[Gary Allan]

I'd post up in the Racing section/forum. There someone will be more in tune with your challenges. Good luck with your R&D!

 

[MilesO]

Thanks, Gary, your posts are appreciated.