Another What Oil do u use thread

[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/forum...71&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

[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]

Originally Posted by 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/forum...71&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

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.

Marty

[Dynomite]

Originally Posted by 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

Just for those that do not know what to look for

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



For Details..........Post 79 - Timing Chain Idler Sprocket Lubrication and Installation

[Karl]

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]

Originally Posted by Dynomite

Just for those that do not know what to look for

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



For Details..........Post 79 - Timing Chain Idler Sprocket Lubrication and Installation

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]

Originally Posted by Ccmano

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.

Originally Posted by DRM500RUBYZR-1

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:

Originally Posted by spork2367

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/catal...SABEgLQRvD_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...pecs-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.