Another What Oil do u use thread

[XfireZ51]

Been looking for oil to replace the CASTROL GTX I had been using for a number of years. It is a conventional so wanting a synthetic.
Well, I found MOBIL 1 15W-50. Here are the specs which look like it contains adequate levels of ZDDP. Has anyone else discovered and been using it?

[secondchance]

In 2014, after an engine rebuild, my oil pressure was unusually and uncomfortably low - 15 psi or so. I used Mobil 1 15W-50 just to increase the low rpm pressure 'cause it was the only thing I could do. It turned out to be a crankshaft oil galley plug that popped out.
After years of using Mobil1 and Mobil 1 High Mileage, I gave up a couple of months ago and went to Amsoil Z-Rod 10W-30 over the same concern - ZDDP.

[Gunny]

Amsoil may be your solution. At one time I used M1 high mileage 10W40 that had the higher ZDDP but Mobil "quietly" changed the amount of ZDDP to a lower level. Click HERE (https://mobiloil.com/~/media/amer/us/pvl/files/pdfs/mobil-1-oil-product-specs-guide.pdf) for the current M1 oil specs. I have spec sheets from 2011 & 2014 showing that M1 high mileage 10W30 & 10W40 with a phosphorus level of 1000 and zinc level of 1100. Those levels were reduced some time after 2014 but, without access to later spec sheets, I'm not certain when that happened.

[XfireZ51]

Gunny,

Here’s the link to Mobil product specs on oils. You’ll note that the 15W-50 specifically mentions flat tappets and that the zinc content is within the acceptable range for our motors unlike Mobil 1 High Mileage 10W-40 which I have been using more recently.
The 15W-50 can be had at Walmart, as an example, for $22/5qts. I am changing to this for other reasons in addition to the ZDDP insufficiency.
You’ll note that this .pdf was published just this month, June 2019.

https://mobiloil.com/~/media/amer/us/pvl/files/pdfs/mobil-1-oil-product-specs-guide.pdf
Same link. :)

[spork2367]

There is a thread with literally ALL this information already in it...

http://www.zr1.net/forum/showthread.php?t=30261

15W-50 is considered by most to be a little on the heavy side for a stock LT-5, but I wouldn't be super worried unless you were running it in low temps.

[Flyman 27]

Dom, I also did the same research you did and came to the Mobile 1 15w50 as a possible solution. And, Walmart does carry it regularly, but they also sell it online with free shipping. 5 qts for $23 is pretty darn cheap, but that was not part of the equation when I decided to change.
I have been using the Mobile 1 15w50 for 3 years now without issue. But I do not drive in cold weather at all.

[XfireZ51]

There is a thread with literally ALL this information already in it...

http://www.zr1.net/forum/showthread.php?t=30261

15W-50 is considered by most to be a little on the heavy side for a stock LT-5, but I wouldn't be super worried unless you were running it in low temps.

Always an interesting topic. I would agree w Hans in that thread, that the seat and spring pressures our motors experience(a benefit of 4v OHC architecture) don’t reach what the LS/LT motors need to run for the in-block cam setup to breathe as well. So the need for ZDDP not as great and I think we have examples of being able to “get away with” lower ZDDP content.

[XfireZ51]

Dom, I also did the same research you did and came to the Mobile 1 15w50 as a possible solution. And, Walmart does carry it regularly, but they also sell it online with free shipping. 5 qts for $23 is pretty darn cheap, but that was not part of the equation when I decided to change.
I have been using the Mobile 1 15w50 for 3 years now without issue. But I do not drive in cold weather at all.

I drive in cold weather only on occasion of clear skies and dry roads and then really to just get fluids up to temp and get some of the dust off the brakes and greases moving. For the most part, ZR sits there w neg cable disconnected.I try to start it every few weeks but wait for outside temps to be over freezing.
Good to know Dan.

[secondchance]

Always an interesting topic. I would agree w Hans in that thread, that the seat and spring pressures our motors experience(a benefit of 4v OHC architecture) don’t reach what the LS/LT motors need to run for the in-block cam setup to breathe as well. So the need for ZDDP not as great and I think we have examples of being able to “get away with” lower ZDDP content.

I had this discussion with multiple people including Marc and fully agree spring pressure on on our motor is not as high as OHV engine. However, pressure increases with RPM. Now, our LT5 will see 7,000 RPM at times (hopefully) where as typical OHV V8 seeing 6,000+.
In the end, i decided it simply was not worth the risk and started buying Amsoil online.

[lfalzarano]

I decided not to cheap out on my Z and also use Amsoil. Stick with Marc and not your Piggy Bank!


Sent from my iPhone using ZR-1 Net Registry (http://r.tapatalk.com/byo?rid=90383)

[Ccmano]

Hey Dom,

Due to my location in Japan and even when I was in Hawaii I’ve also looked for alternatives for oil. Last year I liked what I read about Liqui Moly from Germany and gave it a try. I love it so far and no more chain rattle at start up too. I also use it in the Audi and the Benz (different blend and full synthetic) and will probably convert the Harley at the next oil change.

I think there are a lot of opinions and thoughts about the best oil or safest for our motor. I’ve read some old timers have been using regular M1 10W-30 as specified by manufacturer since new and no issues.

If the demise of my LT5 comes with using this oil so be it. So far I love it and redline on a regular basis so I’m not worried. I buy Liqui Moly with free shipping from Amazon ($34 for 5 liters) no matter where I’m living so I love it. I’m not for or against any oil a member uses and just sharing what I’m using even if I’m the only one and don’t care what others think. Yes, this one is not a full synthetic and I change my oil annually regardless of miles. Best wishes with your choice.

Here is an email from one of their engineers:

Dear Craig,

thank you very much for contacting us and your interest in our LIQUI MOLY products.

ZDDP (Zinc Dialkyldithiophosphates) have been a common AW (anti wear) additive comination in the past but have been more and more replaced / displaced by more modern chemical AW and EP (extreme Pressure) additives in modern motor oil formulations due to enviromental regulations and new developed additives.
The API (American Petroleum Institute), ACEA (European Vevicle Manufacter Assosiation) and the vehicle / engine manufacters itself regulate the maximum amount of ZDDP within the motor oil classifications. So as soon as a engine / vehicle manufacter ask for a specific motor oil classification the amount of ZDDP is not decisive, the OEM given specification rules.

Further : it´s never the amount of a single additive that indicates how good one feature (e.g. the wear protection) is. It´s always the combination of several chemicals (the additive package) that gives a oil it´s properties.

Please understand that we do not publish the exact composition of our product formulations. It´s our company´s secret but the specifications and approvals of each of our products are written in the product information which you can find attached to this Email.

For your LT5 engine we recommend you to use our #LM2043 MoS2 Antifriction SAE 10W-40 which is a special development from us made for proven engines from the early 1970´s till the end of the 1990´s. Beside a semi-synthetic base oil, a special additive package (with a Zn amount of approx. 1300 ppm) it also contains the proven additive MoS2 for maximum protection.

Please see the attached product information.

9914

We hope we could help you with our information. Should you have further questions regarding our products we would be very pleased to get contacted from you again.

Best regards

i. A. Steffen Niemietz
Anwendungstechniker
application engineer

F & E / Anwendungstechnik

Phone: +49 731 1420-658
Mobil: +49 162 2815064
Fax: +49 731 1420-44658
steffen.niemietz@liqui-moly.de

LIQUI MOLY GmbH
Jerg-Wieland-Straße 4 | 89081 Ulm | GERMANY

www.liqui-moly.de



Sent from my iPhone using ZR-1 Net Registry (http://r.tapatalk.com/byo?rid=90383)

:happy1:

[HAWAIIZR-1]

:happy1:

I don’t question German Engineering!!! 👍🏻🤙🏼

[Ccmano]

I don’t question German Engineering!!! 👍🏻🤙🏼

I was going to say... that’s the most intelligent thing I’ve see on this subject it some time!
H
:cheers:

[-=Jeff=-]

Why don't you use Amsoil? You can get it from Marc.. I use Amsoil in all my cars now

[Paul Workman]

Always an interesting topic. I would agree w Hans in that thread, that the seat and spring pressures our motors experience(a benefit of 4v OHC architecture) don’t reach what the LS/LT motors need to run for the in-block cam setup to breathe as well. So the need for ZDDP not as great and I think we have examples of being able to “get away with” lower ZDDP content.

Seat & spring pressure advantage goes to the DOHC configuration, true. But, they (LS motors) ALSO use roller lifters, and it is those flat rappet lifters combined w/ rpm potential (not fogetting the force required to overcome (valve/spring) inertia increases @ the square of the RATE of the change of motion (speed).

According to LT5 research contained in a paper Marc Haibeck published and delivered too (in BG), ZDDP levels in the 1100/1200 ppm for zinc/phospherous was the spec @ the time the LT5 was first produced. (And, speaking of SPEED, one guess what affect reground cams has on the force (i.e., the scuffing) has on those flat tapper surfaces...)

My point is, I don't see the science in this thread to support reducing ZDDP further w/o proper scientific evidence to support such a conclusion.

Lubrication failure on our lifters is insidious. Therefore it is impractical for we lay ppl to attempt to establish MTBF trending for rhe various (ZDDP) levels. Therefore, for an individual to experiment with reducing ZDDP, one assumes the soul risk with the good luck wishes of us all. Like that famous old cereal (sp?) food commercial: "I'm not going to try it...YOU try it. Wait! Let's get Mikey (a third kid) to try it!"... pause while Mikey tries the new cereal...
"He likes it! ... Hey Mikey!"

Or, as they said about pioneers: "You can recognize the pioneers by the arrows in their backs!" Try lowering ZDDP? :happy1:

[Young1]

My next oil change this year shall be with Brad Penn 10w40.

[Paul Workman]

BTW... weren't you high on Rotella @ one time?

[lfalzarano]

Paul, you can lead a horse to water, but you can’t make him drink.


Sent from my iPhone using ZR-1 Net Registry (http://r.tapatalk.com/byo?rid=90383)

[XfireZ51]

Thought I would post an update. I drained the Mobil 1 High Mileage and replaced oil filter, then put in a fill of Mobil 1 15W-50. Having driven about 300mi. now with it, I can see a significant difference in the exhaust. Previously, I had a black sootiness on the exhaust tips that accumulated rather quickly. After having driven it, the exhaust tips have a thin coloration on them but I can still see the chrome shine through the film coating. Motor appears to be running much cleaner so far. Pressure etc. are all good or a bit better than previous.

[Meanmyz]

Paul, you can lead a horse to water, but you can’t make him drink.


Sent from my iPhone using ZR-1 Net Registry (http://r.tapatalk.com/byo?rid=90383)

After reading this thread, I guess so. I am kind of surprised. I will stick with Amsoil AMO 10W-40. ;) :cheers:

[lfalzarano]

Right decision.


Sent from my iPhone using ZR-1 Net Registry (http://r.tapatalk.com/byo?rid=90383)

[Paul Workman]

Always an interesting topic. I would agree w Hans in that thread, that the seat and spring pressures our motors experience(a benefit of 4v OHC architecture) don’t reach what the LS/LT motors need to run for the in-block cam setup to breathe as well. So the need for ZDDP not as great and I think we have examples of being able to “get away with” lower ZDDP content.

Dom, You may be correct, but I'd argue that the LT5 spring/seat specs of the motor hasn't changed. So, where's the justification/evidence to suggest that lesser (ZDDP) than what was originally "spec'ed" (i.e., API SG, SH) is acceptable?

And, in the case of using cams with a modified lift and lift rate profile, isn't it reasonable to assume the lubricity of the oil would (if anything) need to be increased - certainly NOT decreased?

The wear on the LT5 lifter is insidious. Making matters worse, it isn't easy to collect lifter wear data w/o at least perhaps removing the cams to access/measure lifter wear (using a depth micrometer). Removing and re-phasing the cams means pulling the motor to do so, all to facilitate making the lifter wear assessment(s). So, w/o taking the trouble to pull the engine periodically to gauge the wear progression on the lifters, do we really want to imply reducing ZDDP with ZERO on so little (or none) comparison of wear data to go on?[-X

You may very well be correct in saying LESS ZDDP may be OK, at least in certain circumstances (not everyone drives the same way). But, to do so would be in spite of supporting evidence and not because of it.:cheers:

[ZWILD1]

On my first 91 Z I used either Red Line full synthetic or the Mobile 1 15W50 during the summer. That car I drove a bit during the winter later on in it's life and I would use a lower viscosity Mobile 1 during the winter months. On my current car I use what the previous owner used and that is Amsoil recommended by Marc Haibeck. I couldn't find it local so I went on line to Amsoil and joined their preferred customer account. It saves me a bunch on the cost. I now use their products in our cars and even my John Deere and ATV .

[XfireZ51]

Dom, You may be correct, but I'd argue that the LT5 spring/seat specs of the motor hasn't changed. So, where's the justification/evidence to suggest that lesser (ZDDP) than what was originally "spec'ed" (i.e., API SG, SH) is acceptable?

And, in the case of using cams with a modified lift and lift rate profile, isn't it reasonable to assume the lubricity of the oil would (if anything) need to be increased - certainly NOT decreased?

The wear on the LT5 lifter is insidious. Making matters worse, it isn't easy to collect lifter wear data w/o at least perhaps removing the cams to access/measure lifter wear (using a depth micrometer). Removing and re-phasing the cams means pulling the motor to do so, all to facilitate making the lifter wear assessment(s). So, w/o taking the trouble to pull the engine periodically to gauge the wear progression on the lifters, do we really want to imply reducing ZDDP with ZERO on so little (or none) comparison of wear data to go on?[-X

You may very well be correct in saying LESS ZDDP may be OK, at least in certain circumstances (not everyone drives the same way). But, to do so would be in spite of supporting evidence and not because of it.:cheers:

Paul,

The ZDDP in the Mobil1 15W-40 is 1200 Zinc/1300 Phosphorous. Both Pete and I have seen my cams numerous times in the recent past including last winter. Lifters and lobes look like new and they have been installed 4 years ago and have about 20k on them. The Mobil1 15W-40 is specified for race motors and flat tappet cams.
I’ll keep u posted if I have any problems.

[SBAquaLT5]

I'll throw more fuel on the fire..



What are you guys seeing for "hot" idle oil pressure? With Amsoil 10W40 at 200F Oil Temp I'm seeing 39PSI idle, and 65PSI at 2000RPM. Granted these gauges are not 100% accurate, that seems high. GM service manual says minimum oil pressure at idle should not be below 12 PSI.



I know everyone likes Haibeck's Amsoil 10W40 for ZDDP, but has anyone looked into 5W40 weight? Seems like a good compromise for quicker oil flow on cold starts. Thinking of writing Marc about that.

[Paul Workman]

Paul,

The ZDDP in the Mobil1 15W-40 is 1200 Zinc/1300 Phosphorous. Both Pete and I have seen my cams numerous times in the recent past including last winter. Lifters and lobes look like new and they have been installed 4 years ago and have about 20k on them. The Mobil1 15W-40 is specified for race motors and flat tappet cams.
I’ll keep u posted if I have any problems.

Yup! We're in "violent agreement" again, Dom. I wuz taking exception to implications which may have been left adrift in the statements in post #7.

Left un-checked, it seemed to me some would be left with the impression that because of the reduced spring/seat tension of the LT5 (compared to pushrod motors) that the ZDDP level could be reduced or less than the 1200/1300 ppm originally specified for the LT5.

The fact IS, some receding from the "1200/1300" spec might work for some driving conditions, e.g., those whose LT5s seldom see much track or drag strip duty, i.e., some 60% of ZR-1 drivers (according to a "who has hit the rev limiter (on their cars)" post - some years back. However, who among us is qualified to guarantee that reducing ZDDP to "X/Y" ppm is OK...OK w/o a spec of test data to support such a reduction. (Generally speaking: sometimes it is better to not pick a fight with "factory specs" , especially when it results in little more than reducing the margin for error in favor of some arbitrary and capricious but more economical "solution"...was my point: all present thread contributors excepted.)

[Karl]

I just had Blackstone labs analyize my last seasons Mobile 1 and the zinc content reads 750ppm versus their advertised 900ppm.

Although I have never had a problem with the oil and I drive my car aggressively whenever I can I am officially dropping Mobile 1 for amsoil z-rod 10w/30.

No need to worry Mobil 1 I may still use your product in my Prius....

Btw they said my engine oil analysis was great and my motor shows no wear, contaminants, or problems!

[Dynomite]

Post 3 - LT5/ZR-1 Fluids (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp.html#post1580070550)

https://cimg7.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/800x600-1/80-353a8770_2463_4a3d_bd53_860920b2b618_1__215baaf45f a8310b57b69078bd80040f5003d62d.jpg

Amsoil 10w-40 Recommendation/Analysis (http://www.zr1specialist.com/HAT%20Web/articles/Modern%20Motor%20Oil%20and%20the%20LT5%20Engine.pd f)

Amsoil 10w-40 (https://www.amsoil.com/shop/by-product/motor-oil/gasoline/premium-protection-10w-40-synthetic-motor-oil/)

[Top Toy]

I started using Amsoil Z-Rod a few years ago because 1). Has high ZDDP content 2). Has extra corrosion inhibitors to protect an infrequently run motor and 3) Comes closest (10W-30) to the viscosity originally spec'd by GM for our motors. This oil is formulated specifically for flat tappet, high performance engines that may sit idle for extended periods of time. Works for me.

Sent from my SM-G975U1 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[XfireZ51]

Paul,

Pete is currently “refurbing” my motor. I can tell u that after about 2 years of using the Mobil 1 10W-40 High Mileage, the cam lobes and tappets are in very good shape. No wear shown. And we know that the 10W-40 has a ZDDP spec lower than what we consider adequate for protecting our flat tappets.
These are Pete’s cam regrinds. So just a data point for the discussion.
More recently, ie last summer, I have switched to the Mobil 1 15W-50 which does have a 1200+ spec for ZDDP.

[Ccmano]

Did a little research today. My 1990 owners manual specifies 10w30 type “SG” spec oil for the ZR-1/LT5. On the website Bobistheoilguy.com site I found the original ZDDP spec for type “SG” spec oil was at level of 1000 - 1400 ppm back in the 1990’s.
https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=printthread&Board=1&main=73571&type=thread

I assume therefore that the original minimum engineering spec for ZDDP is probably ~1000ppm. It is also probably safe to assume that any oil with a ZDDP spec of 1000ppm to 1400ppm that otherwise meets “SG” spec. is correct.

That said, I still believe the concern for ZDDP levels in our cars is wildly overblown. The original failures reported were exclusively in high performance push rod flat tappet engines with high lift cams and extraordinarily high valve spring pressures. While our engine may have “flat Tappets” or buckets our valve spring pressures are less than half of those where these issues showed themselves. When they talked about “flat tappet” engines Overhead Cam engines were not in the mix.

Should we err on the side of caution, by all means. It is certainly wise to make sure the oil we use has at least 1000ppm of ZDDP. Conversely, those that don’t are certainly not in imminent danger of cam failure. My guess is that most of the ZR-1 currently running around today are on a modern oil like Mobil One with the lower ZDDP rating. We certainly don’t see cam failures left and right. As a matter of fact cam failures remain exceedingly rare.

That’s my 2 cents, your mileage may vary.
H
:cheers:

[Karl]

I am not a fan of using a 40 weight oil in a motor designed to use a 30 weight oil.

The amsoil Z rod on eBay it is only ~$9 more for 5 quarts with free shipping and handling than the high end Mobile 1 in Walmart.

[Dynomite]

As an engine wears with mileage you can in general use heavier oils.
The wt of oil to use also depends on the average operational environmental temperatures.
I use a 180 deg unmodified New Thermostat in all engines.

The wt of oil also depends on your engine cooling system if you operate the engine on the 'Hot" side or "cool" side.
I use Amsoil 10w-40 in the LT5 engines.

I use Mobile 1 10w-30 in the L98 engines.

I use After Market Aluminum Radiators and in general operate in "warm" Climates but have operated at Air temperatures of 30-50 degs F.

[rkreigh]

no doubt that the amsoil stuff is very good


LPE recommended 15/50 in summer and 10/40 on the LSV 390


I stuck with that using wally world jugs and changed oil probably too often, but when we pulled the engine apart at 106k the liners, pistons, cams, and all looked good


the one "concern" was that the idler shaft for the cam chain drives had some wear which was a bit odd

[DRM500RUBYZR-1]

Did a little research today. My 1990 owners manual specifies 10w30 type “SG” spec oil for the ZR-1/LT5. On the website Bobistheoilguy.com site I found the original ZDDP spec for type “SG” spec oil was at level of 1000 - 1400 ppm back in the 1990’s.
https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=printthread&Board=1&main=73571&type=thread

I assume therefore that the original minimum engineering spec for ZDDP is probably ~1000ppm. It is also probably safe to assume that any oil with a ZDDP spec of 1000ppm to 1400ppm that otherwise meets “SG” spec. is correct.

That said, I still believe the concern for ZDDP levels in our cars is wildly overblown. The original failures reported were exclusively in high performance push rod flat tappet engines with high lift cams and extraordinarily high valve spring pressures. While our engine may have “flat Tappets” or buckets our valve spring pressures are less than half of those where these issues showed themselves. When they talked about “flat tappet” engines Overhead Cam engines were not in the mix.

Should we err on the side of caution, by all means. It is certainly wise to make sure the oil we use has at least 1000ppm of ZDDP. Conversely, those that don’t are certainly not in imminent danger of cam failure. My guess is that most of the ZR-1 currently running around today are on a modern oil like Mobil One with the lower ZDDP rating. We certainly don’t see cam failures left and right. As a matter of fact cam failures remain exceedingly rare.

That’s my 2 cents, your mileage may vary.
H
:cheers:

Your post is to the point and frames the concern and reality perfectly.

The only $0.01 that I can add are the oil companies have certainly added other, newer anti wear compounds that may not even have been around back when ZDDP was king, to today's modern formulations.
As far as weight, Doug Rippie required 10-40 back in 1993 for my modified motor.
:cheers:
Marty

[Dynomite]

no doubt that the amsoil stuff is very good

LPE recommended 15/50 in summer and 10/40 on the LSV 390

I stuck with that using wally world jugs and changed oil probably too often, but when we pulled the engine apart at 106k the liners, pistons, cams, and all looked good

the one "concern" was that the idler shaft for the cam chain drives had some wear which was a bit odd

Just for those that do not know what to look for :p

That oil port is very small in the Idler Shaft for the amount of needle bearings it is lubricating (make sure it is clear when assembling). Those are needle bearings in the Idler Sprocket ;)

https://cimg2.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/350x300-1/80-sidlerrace_zps777ae9a6_1__580b6f66eb5a96004022eec9 f776e58a7dfd9d11.jpghttps://cimg1.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/350x300-1/80-schainidlersprocket2_zpse3eb308a_1__283e4ad5aabd4a 7bdb89e00b5c654f8820510338.jpg

For Details..........Post 79 - Timing Chain Idler Sprocket Lubrication and Installation (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-4.html#post1581690558)

[Karl]

https://i.postimg.cc/14Z11yVh/IMG-20191203-081949.jpg (https://postimg.cc/14Z11yVh)

This is Mobile 1 Extended Performance 5W30 full synthetic with the gold label.

I can scan a better image another time. Hope this is view able enough.

[rkreigh]

Just for those that do not know what to look for :p

That oil port is very small in the Idler Shaft for the amount of needle bearings it is lubricating (make sure it is clear when assembling). Those are needle bearings in the Idler Sprocket ;)

https://cimg2.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/350x300-1/80-sidlerrace_zps777ae9a6_1__580b6f66eb5a96004022eec9 f776e58a7dfd9d11.jpghttps://cimg1.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/350x300-1/80-schainidlersprocket2_zpse3eb308a_1__283e4ad5aabd4a 7bdb89e00b5c654f8820510338.jpg

For Details..........Post 79 - Timing Chain Idler Sprocket Lubrication and Installation (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-4.html#post1581690558)


I'm tempted to open that hole up just a little as my shaft looked like it was oil starved or the bearings weren't rolling / true It dug a very small wear mark that would be easy to miss if we weren't looking for it.


Oddly enough the liner that wore was likely oil starved to but it wore at the bottom like the piston skirt was diggin in a bit (390 stroker) 3.875 sonny bryant crank that almost makes you think the nosebleed price is worth it!!


thank goodness most of my "hard parts" were ok. Thanks for the pics!!

[spork2367]

I assume therefore that the original minimum engineering spec for ZDDP is probably ~1000ppm. It is also probably safe to assume that any oil with a ZDDP spec of 1000ppm to 1400ppm that otherwise meets “SG” spec. is correct.

That said, I still believe the concern for ZDDP levels in our cars is wildly overblown. The original failures reported were exclusively in high performance push rod flat tappet engines with high lift cams and extraordinarily high valve spring pressures. While our engine may have “flat Tappets” or buckets our valve spring pressures are less than half of those where these issues showed themselves. When they talked about “flat tappet” engines Overhead Cam engines were not in the mix.

Should we err on the side of caution, by all means. It is certainly wise to make sure the oil we use has at least 1000ppm of ZDDP. Conversely, those that don’t are certainly not in imminent danger of cam failure. My guess is that most of the ZR-1 currently running around today are on a modern oil like Mobil One with the lower ZDDP rating. We certainly don’t see cam failures left and right. As a matter of fact cam failures remain exceedingly rare.


Keep in mind, ZDDP reduction is relatively recent by automotive standards. It didn't just effect vehicles with super high lift cams or excessive spring pressure.

From a Super Chevy article: "There are two ways a person can ensure they are using oil that has sufficient amounts of antiwear additives, commonly listed as 1,200 ppm ZDDP for flat-tappet engines with stock valve springs and 1,400 ppm for engines with higher spring rates."

Part of the reason LT5's have very few cam failures is because as a fleet of 6000 some vehicles, they have relatively low mileage. The average mileage is nowhere near long term cam failure points.

The only $0.01 that I can add are the oil companies have certainly added other, newer anti wear compounds that may not even have been around back when ZDDP was king, to today's modern formulations.

ZDDP is still king. It was reduced to to EPA guidelines because it kills catalytic converters. Nothing new has come along to replace, supersede or improve upon it.

From the other oil thread:


The EPA is the reason oils reduced the amount of ZDDP. More because of the phosphorus than the zinc. But both are needed together for the protective anti-scuffing properties of the ZDDP. The phosphorus is detrimental to the catalyst, so over time increases emissions.

Currently, diesel oil is limited to 1200 ppm phosphorus and passenger car oil to 800 ppm phosphorus (for 20 and 30 grade oils, 40 and above are exempt). No commercial "automotive" oil will contain more than 800 ppm or diesel more than 1200 ppm. Racing oils and "high performance" oils are not subject to this. Basically, if you can buy it at Advanced Auto, Autozone, whatever, it has no more than 800 ppm.

I use Brad Penn which contains 1500 ppm zinc and 1400 ppm phosphorus in a proprietary blend of Zinc Alkyldithiophosphate and p-dodecylphenol. This is for their high performance oil line. Brad Penn is the oldest operational refinery in the US (former Kendall refinery). They use 100% PA grade crude oil. Interesting history if you have time to kill.

That being said, today's oils offer more protection than previous oils, with ZDDP levels being equivalent. But, two modern equivalent oils with one having less ZDDP will never offer the same level of protection as the oil with more ZDDP.

I work in a facility (one of the VERY few) that produces new OEM flat tappet piston engines. Ours happen to be air cooled aircraft engines (we make roller tappet engines as well). Like automotive oil, aircraft oil has also been limited in it's ZDDP levels. It is important enough that we specify an additive to be added to our engines that is just ZDDP.

https://www.aircraftspruce.com/catalog/eppages/lycoiladditive.php?gclid=EAIaIQobChMI6syA7cne4AIVC 61pCh19LgPPEAQYASABEgLQRvD_BwE

To really solidify the importance of this, because we are aware people won't add this and generally use the wrong thing when given the opportunity, on our high performance engines, we spent about 10 years and millions of dollars perfecting a DLC (diamond like carbon) coating for flat tappet lifters. This coating can be as much as 50% harder in microindentation tests than natural crystaline diamond.

These are engines that carry 10 times the liability of automotive engines. We have a lab that rivals that of any automotive engine manufacturer right up to a scanning electron microscope. So we have done extensive internal and external testing on this.


Now, will your engine fail if you throw 11 quarts of Walmart's finest engine oil in there....unlikely. Once an engine is broken in, destructive scuffing is only likely to occur with debris in the oil, under oil starvation, or under sustained high RPM loading. So the average driver puttering around in their ZR-1 is going to be fine. However the engine will see more wear with less ZDDP under all conditions.

There is some debate about break in. We actually don't recommend the a ZDDP additive during break in. Our engines are all run on an engine dyno and the break in is at a very uniform operating RPM. The ZDDP could actually prolong the time needed for break in. In cars, break in is typically more difficult as you can't control the ideal conditions and much more time is spent at low RPMs vs. in the ideal higher operating RPM range. My opinion would be that unless you can be 100 percent certain that you can maintain break in conditions, you would be better off with the ZDDP prolonging the break in period while still offering protection. That won't really be applicable to most ZR1 owners. Cars with less than 1500 miles would be well suited to using a non synthetic moderate ZDDP level oil until broken in.

Mobile 1 today isn't mobile one of 1990. Any comparison between the two is laughable. GM is going to tell you to run it, because they don't know anything else and probably have some contractual obligation.

Is it bad oil? No. I run the Mobile 1 high mileage in my wife's Acura and both my Dodge trucks.

Is it the best oil for our cars? Not by a long shot.

Here is a list of all Mobile 1 oils phosphorus and zinc contents:

https://mobiloil.com/~/media/amer/us/pvl/files/pdfs/mobil-1-oil-product-specs-guide.pdf

The Amsoil 10W-40 that has been posted is a good choice with 1378 ppm zinc, and 1265 ppm phosphorus. Although the Amsoil Z-Rod comes in at 1440 ppm zinc and 1320 ppm phosphorus.