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Re: ZDDP article [Re: 1968RR] #1764040
03/02/15 08:04 PM
03/02/15 08:04 PM
Joined: Feb 2012
Posts: 4,443
Morristown Tn.
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71birdJ68 Offline
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Morristown Tn.
Here is something I'm curious about, and think this might be good for cars also. Mobil1 has a motorcycle oil that is made for bike engines where the trans, and clutch use the same oil as the motor. It is designed for shearing action of gears, and wet clutches. So, would that be good for us also?

Re: ZDDP article [Re: Mattax] #1764041
03/02/15 08:16 PM
03/02/15 08:16 PM
Joined: Sep 2005
Posts: 6,516
Santa Cruz, California
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Lefty Offline
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Santa Cruz, California
Quote:

Quote:


Real eye opener if this guy is on the mark? Kinda tosses most diesel oil out the window. Cost per quart looks like Mobil 1 5W-30 Full Synthetic is the winner.




Scar test is just one of several indicators of actual in use performance to consider. Probably a more important test for greases than motor oil. Although I tip my hat to him for going through the trouble to do this test, there are questions about the control of his procedures, test environment and equipment. That doesn't mean they are or are not valid results, just we can't be sure.

"Choosing engine oil for Corvairs" by Widman is probably the most readable overview of motor characteristics. It covers viscosity, pour point, differences in base stocks, and a bit on additive packages. Read that and you'll have a much more complete view of motor oil performance.
Illustrated Pdf in English from his hobby pages http://www.widman.biz/Corvair/English/Links/Links.html or his business pages http://www.widman.biz/English/Selection/oil.html

Also on his websites are some other good papers on gear oils and case studies of failures he's had to deal with.




Good info thanks. I'm mostly interested in flat tappet cam lobe protection. I figure if it can protect the cam lobe, the crank/rod/cam bearing wear will be low as well.

So now I'm thinking I want the highest HTHS (ASTM D4683) combined with the lowest viscosity.

What is the difference between the "viscosity index" and the viscosity ratings at 40C and 100C or more importantly, which rating/measurement is most important to look for in motor oil? I'm thinking the 100C measurement.

Re: ZDDP article [Re: Lefty] #1764042
03/02/15 10:26 PM
03/02/15 10:26 PM
Joined: Feb 2010
Posts: 1,645
Phila. Pa.
Mattax Offline
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Phila. Pa.
My memory is the VI is another way of describing the spread between 40 C and 100 C. But I'm going to have to reread the article to be sure.

Since this is the 'race' forum, the important temperature ought to be done with a temperature sensor in the oil pan. So, for example, my old 340 ran 280-300 F on the highway. There were some issues in my exhaust and remote oil filter routing, which I eventually addressed. It still ran 260-270F at highway speeds. Unfortunately, I didn't understand about pour points and was suspicous of the synthetic sales pitches. So I ran non synthetic 20W-50 racing oil. That might have made sense for the highway driving and racing once warmed up, but probably was not getting the flow needed until it was up to full temperature. Certainly was caused accusumps 100 psi relief valve to pop open a few times. yuck.

The oil in my current 340 runs 160-190 degrees F on the street. At the beginning of a run, sometimes its not even at 160. So for this engine, both the 40 C and 100 C viscosity are important to me, as is the pour point. With the higher valve spring pressures, the tried and true ZDDP type anti-wear package was also important. Brad Penn 5W-30 fit the bill.
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edit: That was a long way of saying that I've come around to placing first priority on viscosity.
The article that helped me understand that was Oil 101 by AE Haas. There's a couple versions floating around the web. I linked this one because it has the final paragraphs where he starts to get into temperature on road course versus street driving. Haas was a physician applying his understanding of fluids to explain viscosity, pressure and flow to his fellow auto enthusiasts.

Last edited by Mattax; 03/02/15 11:02 PM.
Re: ZDDP article [Re: 1968RR] #1764043
03/02/15 10:53 PM
03/02/15 10:53 PM
Joined: Feb 2005
Posts: 4,309
Prospect, PA
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The primary goal of the research was really to see whether or not neutron activation analysis (NAA) was better for quality control purposes than the industry standard, ICP-AES. The uncertainties show that NAA is MUCH more accurate than ICP-AES. I understand that most oil manufacturers don't necessarily have regular access to a nuclear reactor, but ICP-AES is a really lousy way to determine additive concentrations
:




I don't think there was a scientific analysis between the two regarding uncertainty. I don't think his method for uncertainty analysis is necessary even valid. I would think matrix spike would be the method of choice or at a minimum part of the analysis. And in the final analysis, if the ICP is 5% off, does that really change anything. Does anyone think that good verses bad oil would have anything to do with it being 1200 ppm +/- 5%.

Finally, I've done undergrad research, and have managed undergrad researchers. Always interesting stuff. Never even close to authoritative.

Re: ZDDP article [Re: BSB67] #1764044
03/02/15 11:19 PM
03/02/15 11:19 PM
Joined: Nov 2005
Posts: 1,943
San Angelo, Texas, U.S.A.
1968RR Offline OP
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Quote:

Quote:

The primary goal of the research was really to see whether or not neutron activation analysis (NAA) was better for quality control purposes than the industry standard, ICP-AES. The uncertainties show that NAA is MUCH more accurate than ICP-AES. I understand that most oil manufacturers don't necessarily have regular access to a nuclear reactor, but ICP-AES is a really lousy way to determine additive concentrations
:




I don't think there was a scientific analysis between the two regarding uncertainty. I don't think his method for uncertainty analysis is necessary even valid. I would think matrix spike would be the method of choice or at a minimum part of the analysis. And in the final analysis, if the ICP is 5% off, does that really change anything. Does anyone think that good verses bad oil would have anything to do with it being 1200 ppm +/- 5%.

Finally, I've done undergrad research, and have managed undergrad researchers. Always interesting stuff. Never even close to authoritative.



ICP-AES can only achieve 5% uncertainties if concentrations are very high. For concentrations in the range of motor oil ZDDPs, the uncertainties are more like 15%. I think uncertainties that high would be significant, maybe not for the consumer, but certainly for quality control purposes.
While the research was done as part of an undergraduate project (I'm not one of the undergrads), it was done at a facility that has a dedicated NAA lab (UT's Pickle Research Center). Simply put - there is literally no method of detecting trace elements more accurate than NAA. Given the fact that charges for analyzing samples are in the $50 to $100 range, it seems like a viable option for quality control.


"When I'm in a slump, I comfort myself by saying if I believe in dinosaurs, then somewhere, they must be believing in me. And if they believe in me, then I can believe in me." - Mookie Wilson
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