Motor Oil

[Patrick H.]

Re: Motor Oil

Patrick----


I believe that 94-95 LT5's were factory-filled with Mobil 1.

Joe,

I believe that they were since at least 1992. My point is that I highly doubt that if the ZR-1 owners used Mobil1 (as per factory directions) they would have a camshaft fail - even using the Mobil 1 available today (in case that actually differs in ZDDP concentration).

Patrick

[Patrick H.]

Re: Motor Oil

I agree. Like my Cosworth Vega I believe the nineties ZR-1 DOHC engine has a direct acting valvetrain and loading is likely modest. As I said before, I have seen Cosworth Vega engines that have been abused beyond believe, but worn cam lobes are essentially unheard of.

BTW that's 800 ppm P, not ZDDP. P (phosphorous) is the surrogate element for measuring ZDDP concentration.

Once added, ZDDP cannot be directly determined, but spectroscopic analysis breaks down the molecule and the amount of phosphorous can be measured.

Duke

OK, thanks.
Any idea how that computes into a "percentage"? The other article cited above discusses percentage, and it becomes an apples-and-oranges comparison.

Patrick

[Duke W.]

Re: Motor Oil

1000 ppm = 0.10%

Hey, you're a physician and had to take more chemistry than I did.

Duke

[Jean C.]

Re: Motor Oil

Thanks Duke.
Best regards,

[Tom M.]

Re: Motor Oil

Yeah , Thanks Pat , for your input, My engine builder Holbrook from Livonia said he would finish the motor as is ,But would not stand behind it
with a solid flat tappet cam, Because of the motors that have come back to him in the last year or two with lobe and lifter problems,
"SOME' not all of his engines, It has cost him lots of money.

Tom

[James W.]

Re: Motor Oil

Patrick,

I am not a "the sky is falling" person and have built a few engines myself. Sometimes anectodal evidenece is the first to show, followed sometime later by hard data. Personally, I don't feel that a change to an oil that has a higher ZDDP content is unreasonable, especially if the consequences of not doing so is a nuked engine. I have not personally suffered cam or lifter failure, but a change in oil is a small price to pay for peace of mind. This is another example where you pays your money and you takes your chances.

Jim

[Joe C.]

Re: Motor Oil

"There is, on the other hand, research that concludes the minimum ZDDP requirement is directly related to the lifter
foot pressure. In one SAE paper it is reported that: “at a ZDP level corresponding to 0.02% phosphorus, scuffing
occurred at 200 pounds lifter load, while it required 240 and 480 pounds lifter load for oils containing 0.04 and
0.06% phosphorus, respectively, to initiate scuffing. At 0.08% phosphorus concentration, no scuffing occurred up
to 600 pounds lifter load, the test hardware limit. Scuffing occurred at 350 pounds lifter load with no ZDP
(0% phosphorus).” 1


1. P.A. Bennett, “A look at the Effects of Lubricant Additives on Surfaces,” SAE pub. 580111, (January 1958), 6.


$$$$$$$$$$$$$$$$$$$$$$


From the excerpt above, there is very little to go on, unless someone can post the full copy of Mr. Bennett's paper. In the ZDDPlus Tech brief, none of Mister Bennett's test variables are mentioned, specifically, engine speed/range of speeds/cycling rate(s) (if applicable). Duration of test is not mentioned, either.

Assuming that "lifter foot pressure" is roughly equal to valve spring pressure, the results posted here seem very optimistic. According to the graph, no scuffing occurred @ 800ppm ZDDP concentrations with lifter foot pressures (ie: valve spring pressures) as high as 600 pounds!
Considering the fact that typical 3911068 valve springs deliver NO MORE THAN about 250 pounds force @ 0.45" lift, then it would seem that we are all well within a safe zone if using any stock GM valve spring.

Indeed, even if we use some of the stiffest (to use one of Duke's colloquialisms) "gorilla springs", then the generated loads would still not exceed about 70 per-cent of the threshold 600 pounds force necessary to cause scuffing, according to the graph below.

It is important to remember that lifter loading is cyclical, and many engine builders are now seeking to minimize the likelihood that any particular lifter will stop rotating in its bore. The best way to do this is to observe very close tolerances in lifter to bore clearance, and more importantly, lifter thrust alignment. You'll notice that any race engine which is restricted to flat tappet camshafts by class rules, will have the lifter bores trued and bronze bushed, as well as having the camshaft nitrided, to help ensure camshaft/lifter durability.

In a street driven engine, even with preventive measures, if any scuffing occurs, then the likelihood that it will occur again increases with each episode. Eventually, the lifter will stop rotating within its bore, and lobe failure is then imminent.

Joe

[Bill B.]

Re: Motor Oil

"There is, on the other hand, research that concludes the minimum ZDDP requirement is directly related to the lifter
foot pressure.
occurred at 200 pounds lifter load, while it required 240 and 480 pounds lifter load for oils containing 0.04 and
0.06% phosphorus, respectively, to initiate scuffing. At 0.08% phosphorus concentration, no scuffing occurred up
to 600 pounds lifter load


$$$$$$$$$$$$$$$$$$$$$$


From the excerpt above, there is very little to go on, unless someone can post the full copy of Mr. Bennett's paper. In the ZDDPlus Tech brief, none of Mister Bennett's test variables are mentioned, specifically, engine speed/range of speeds/cycling rate(s) (if applicable). Duration of test is not mentioned, either.

Assuming that "lifter foot pressure" is roughly equal to valve spring pressure, the results posted here seem very optimistic. According to the graph, no scuffing occurred @ 800ppm ZDDP concentrations with lifter foot pressures (ie: valve spring pressures) as high as 600 pounds!
Considering the fact that typical 3911068 valve springs deliver NO MORE THAN about 250 pounds force @ 0.45" lift, then it would seem that we are all well within a safe zone if using any stock GM valve spring.

Indeed, even if we use some of the stiffest (to use one of Duke's colloquialisms) "gorilla springs", then the generated loads would still not exceed about 70 per-cent of the threshold 600 pounds force necessary to cause scuffing, according to the graph below.

It is important to remember that lifter loading is cyclical, and many engine builders are now seeking to minimize the likelihood that any particular lifter will stop rotating in its bore. The best way to do this is to observe very close tolerances in lifter to bore clearance, and more importantly, lifter thrust alignment. You'll notice that any race engine which is restricted to flat tappet camshafts by class rules, will have the lifter bores trued and bronze bushed, as well as having the camshaft nitrided, to help ensure camshaft/lifter durability.

In a street driven engine, even with preventive measures, if any scuffing occurs, then the likelihood that it will occur again increases with each episode. Eventually, the lifter will stop rotating within its bore, and lobe failure is then imminent.

Joe

Joe - Where is the rest of the article? "In addition, the industry".....

Bill

[Joe C.]

Re: Motor Oil

Joe - Where is the rest of the article? "In addition, the industry".....

Bill

Bill,

Click on James White's posted link of yesterday 07:45.

[Perry M.]

Re: Motor Oil

Just one more question so I can rest, please. Our company uses Chevron DELO 400 LE SAE15W-40 in all of the trucks and equipment, both gas and desiel. It is rated CJ4. I looked up the MSDS sheets and it states that the amount of Zinc Alkyl Dithiophospate is 1-2%weight. Shouldn't it state .12% weight? I am confused.

[Bill B.]

Re: Motor Oil

Bill,

Click on James White's posted link of yesterday 07:45.

.....Got it! Thanks, Bill

[Joe L.]

Re: Motor Oil

Joe,

I believe that they were since at least 1992. My point is that I highly doubt that if the ZR-1 owners used Mobil1 (as per factory directions) they would have a camshaft fail - even using the Mobil 1 available today (in case that actually differs in ZDDP concentration).

Patrick

Patrick----


1990-92 LT5 engines were not factory-filled with Mobil 1. That started in either 1993 or 1994. I'm sure 1994 and 1995 used it, but I was less sure about 1993. However, now that I think more about it, I think the change occurred when the horsepower rating was upgraded from 375 to 405, which was for the 1993 model year.

Also, I agree that the current Mobil 1 should work just fine in any LT5 engine originally filled with Mobil 1. In fact, I think that ANY LT5 engine, originally filled with Mobil 1 or not, would do just fine on current Mobil 1.

[Duke W.]

Re: Motor Oil

Just one more question so I can rest, please. Our company uses Chevron DELO 400 LE SAE15W-40 in all of the trucks and equipment, both gas and desiel. It is rated CJ4. I looked up the MSDS sheets and it states that the amount of Zinc Alkyl Dithiophospate is 1-2%weight. Shouldn't it state .12% weight? I am confused.

Most engine oil spec sheets do not list the actual mass fraction of ZDDP, but represent it with the mass fraction of P (phosphorous), which is what the API CJ-4 spec limits and the maximum is 0.12% or 1200 ppm.

Here's the 15W-40 Delo LE spec sheet:

https://www.cbest.chevron.com/generated/MSDS/PDS29828895.PDF

Its lists the P and Zn concentrations.

The MSDS sheet:

https://www.cbest.chevron.com/msdsServer/controller?module=com.chevron.lubes.msds.bus.BusMSDSDetail&msdsNumber=17108&docNumber=298288&docDataId=302386&docFormat=HTML&isLoginPage=true&region=NA

lists the actual ZDDP mass fraction, however, MSDS sheets are often generic in nature and may represent a range of products. This is likely why the listed ZDDP fraction covers such a wide range. I always go by the actual product data sheet as in the first link, above, not the MSDS.

BTW, 15W-40 CI-4 Plus Delo:

https://www.cbest.chevron.com/generated/MSDS/PDS7668676.PDF

is also available, but is not likely found in normal retail outlets where we buy oil. It is more likely to be found in farming areas where high sulpher fuel is still in use and CI-4 Plus is better for this application. CI-4 also has 100-200 ppm more P, which means 10-15 percent more ZDDP than CJ-4, however, I consider the level of ZDDP in CJ-4 to be sufficient for vintage engines with OE spec cams and valvetrains.

Chevron does a good job on their product data sheets. If people would read these instead of going by all the BS in marketing/advertising and bubba's Web blogs they would have a better understanding of motor oil particularly what oils have the best anti-wear additive concentration for vintage engines.

Duke

[Duke W.]

Re: Motor Oil

Also, I agree that the current Mobil 1 should work just fine in any LT5 engine originally filled with Mobil 1. In fact, I think that ANY LT5 engine, originally filled with Mobil 1 or not, would do just fine on current Mobil 1.

Given that most ZR-1s have relatively low mileage and see low annual mileage accumulation I would use CJ-4 if I owned one because it has close to the same P concentration as the S-category oils of that era, and the extra P is not going to poison the catalysts anytime soon on typical ZR-1s given the above typical conditions.

I use CJ-4 (or CI-4 if I happen across some) in all my vehicles, which range in model year from 1963 to 1991 including an air-cooled Honda CB1100F motorcycle. They are all low miles for their age and are accumulating miles at a very low rate.

Duke

[Perry M.]

Re: Motor Oil

Thank you Duke. You put my mind at ease and I can finally stop following this thread. This Chevron oil is readily available to me.