motor oil with zinc in a hydraulic roller cam engine

[rcodecj]

Can something like Mobil 1 15w50 synthetic, which has zinc in it be used in a hydraulic roller cam engine without any detriment?

All I can find is info on zinc when using a flat tappet cam and that it is not necessary with a hydraulic roller.
But would it be harmful?

[My427stang]

Not at all, only thing that zinc can hurt at reasonable levels is catalytic converters.  That's why it's not in there, coats the catalytic surface and makes it ineffective, EPA doesn't like that

Regardless, no real pressing need for it once you get rid of the flat tappets, although other wear areas can still benefit a little, that's why it still exists to some significant extent in diesel oils, but absolutely OK to use low zinc (or high) oil for a street motor with a roller cam.

I would also add that most, if not all modern oils have some zinc in there, Mobil 1 itself likely has very little compared to the high zinc oils that we talk about when breaking in cams and running high spring pressures with flat tappets. I certainly wouldn't consider Mobil 1 a high zinc oil, and although I like it very much for a roller motor, I wouldn't dare try it on a fresh flat tappet. 

[blykins]

Just gotta watch about viscosities with hydraulic roller lifters.  Some of the lifters won't meter with thick oil. 

[rcodecj]

Not at all, only thing that zinc can hurt at reasonable levels is catalytic converters.  That's why it's not in there, coats the catalytic surface and makes it ineffective, EPA doesn't like that

Regardless, no real pressing need for it once you get rid of the flat tappets, although other wear areas can still benefit a little, that's why it still exists to some significant extent in diesel oils, but absolutely OK to use low zinc (or high) oil for a street motor with a roller cam.

I would also add that most, if not all modern oils have some zinc in there, Mobil 1 itself likely has very little compared to the high zinc oils that we talk about when breaking in cams and running high spring pressures with flat tappets. I certainly wouldn't consider Mobil 1 a high zinc oil, and although I like it very much for a roller motor, I wouldn't dare try it on a fresh flat tappet.

Ross the 15w50 has 1300 ppm in it,
https://mobiloil.com/~/media/amer/us/pvl/files/pdfs/mobil-1-oil-product-specs-guide.pdf

[rcodecj]

Just gotta watch about viscosities with hydraulic roller lifters.  Some of the lifters won't meter with thick oil.

That's something I did not think about, and good to know!

[My427stang]

Not at all, only thing that zinc can hurt at reasonable levels is catalytic converters.  That's why it's not in there, coats the catalytic surface and makes it ineffective, EPA doesn't like that

Regardless, no real pressing need for it once you get rid of the flat tappets, although other wear areas can still benefit a little, that's why it still exists to some significant extent in diesel oils, but absolutely OK to use low zinc (or high) oil for a street motor with a roller cam.

I would also add that most, if not all modern oils have some zinc in there, Mobil 1 itself likely has very little compared to the high zinc oils that we talk about when breaking in cams and running high spring pressures with flat tappets. I certainly wouldn't consider Mobil 1 a high zinc oil, and although I like it very much for a roller motor, I wouldn't dare try it on a fresh flat tappet.

Ross the 15w50 has 1300 ppm in it,
https://mobiloil.com/~/media/amer/us/pvl/files/pdfs/mobil-1-oil-product-specs-guide.pdf

Neat.  I am pretty loyal to Brad Penn and Valvoline VR1, but good to know

[Barry_R]

Just gotta watch about viscosities with hydraulic roller lifters.  Some of the lifters won't meter with thick oil.

x2
15W-50 is pretty much syrup in this era.

[rcodecj]

Just gotta watch about viscosities with hydraulic roller lifters.  Some of the lifters won't meter with thick oil.

x2
15W-50 is pretty much syrup in this era.

Yea, my 460 was built in the 80's and has had 15w50 in it for years (decades). The last time I pulled a rod cap, the bearings looked like new.
I recently put Mobil 1 0w40 synthetic in it, but it's hard to find a full synthetic that has zinc in it any more.

[e philpott]

The distributor gear will wear out if you don’t have enough zinc during break in . Teeth will be razor sharp and it won’t take long

[Drew Pojedinec]

First thought: vr1 10w30 is hard to beat. If you run a carbureted vehicle you should be changing the oil somewhat often due to possible fuel dilution. Kinda puts synthetic out of its range. (My opinion)

Second thought. Zinc is for sliding metals under high pressure. Stuff like flat tappets.
The EMD engines I work on can have NO zinc in it. We can’t even use galvanized piping. 10ppm and the oil needs to be dumped. These engines often go 50,000 hours between overhauls, so obviously zinc isn’t critical to engine oils in all applications.

[My427stang]

First thought: vr1 10w30 is hard to beat. If you run a carbureted vehicle you should be changing the oil somewhat often due to possible fuel dilution. Kinda puts synthetic out of its range. (My opinion)

Second thought. Zinc is for sliding metals under high pressure. Stuff like flat tappets.
The EMD engines I work on can have NO zinc in it. We can’t even use galvanized piping. 10ppm and the oil needs to be dumped. These engines often go 50,000 hours between overhauls, so obviously zinc isn’t critical to engine oils in all applications.

So oil discussions almost always end up in a fight on forums LOL there is a wide range of "correct"  However, I think that Drew's position mostly closely matches mine.  I change oil regularly, a little less in my EFI motor, but still often, but it's also flat tappet

In the roller 461 we are doing, I intend to build it to use the same Mobil 1 we use in our minivans, likely not 0w20, but off the shelf 10w30 or 10w40.  Not concerned about zinc in any way, I will keep clearances relatively tight and have good drainback.

In the flat tappet 461 on the stand, my 489, and my bench build 390, I run VR1 or Brad Penn, keep in mind, once these pieces are burnished (broken in) you can likely even drop the zinc way back, but I tend to be conservative given the cost benefit and stay with the higher zinc oil, but make no mistake, metal rubbing on metal bathed in oil, makes both smoother and harder. How lucky do you tend to be though LOL  I am not willing to try my luck

Last though, Brent brought up a very serious point that I forgot, mostly because I don't do much hyd roller, and until this build, never a Morel in an FE.  20w50 gives the lifters fits, they are machined to tight tolerances and don't like the thick oil.  Nothing to do with zinc, all to do with viscosity, and unless bearing clearances are real loose, I don't see any reason an engine would want the slow draining oil anyway.  Old school guys like me still look at watery 5w30 and cringe, but if you have the oil film you need, thin is in.

[RustyCrankshaft]

There are also other extreme pressure additives besides zinc/ZDDP. ZDDP was just the least expensive and very effective at its job. A lot of oils like some of the Castrol group III synthetics had/have a "non standard" additive pack that used other metals besides zinc as it's EP additive and they work really well.

In a roller engine(especially with roller tip rockers) I'd be less worried about actual ZDDP numbers. A 30wt is probably as heavy as most street hyd roller lifters want to see. Any good quality oil I think will work fine for rollers. Changing it on time is more important than the oil. Most any good quality oil these days is pretty good in general. At work I did a test with a bunch of different oils, and there was very little difference in oil samples between any of the oils (one or 2 miserable failures, the rest pretty much identical).

There are always cases where you have a specific need that the oil has to address. High sump temps, high sliding loads, flat tappets etc. and in those cases oil selection becomes very important. For most stock, street, and modern engines the correct viscosity and regular changes are the most important thing.

[cjshaker]

I recently put Mobil 1 0w40 synthetic in it, but it's hard to find a full synthetic that has zinc in it any more.

My Honda Hybrids at work use 0 weight full synthetic oil. I just can't see that stuff holding up to ANY sort of shock load, especially in bigger engines with higher rotating weights, not to mention higher wear areas like timing chains and distributor gears, which modern engines don't have.

Unless you're after that last thousandths in ET, I don't see the reasoning for running oil that thin.

[rcodecj]

Funny thing is I expected to see an oil pressure difference with 0w40 vs 15w50 and did not.
It's around 30-35 at idle and 65 tops.
I have 15w50 back in it now but I guess I'll look at a Mobil 1 10w30 with just a bit less zinc, 900 vs 1300 ppm

[RustyCrankshaft]

At operating temp a 0w40 is still a 40wt, or about 14cSt@100*C (there's a range of about 12-16 IIRC for 40wt) .  Interestingly, a thinner oil will sometimes have pretty good load carrying ability due to the base oil being more stable (better HT/HS - High Temp/High Sheer). Ferrari did some testing with 0w20 and found that bearing wear was the same as the factory spec'd 40 and 50 weights and in later years recommended thinner oils. Viscosity is largely dependent on how the engine is set up. A street/strip or race engine with bigger clearances will need more viscosity than a street engine. You need enough viscosity to "plug the hole" and maintain desired oil pressure and temperatures. Too much viscosity is just as bad as too little.

Fortunately in most cases engines can tolerate a wide range of viscosity and not really care but it's a balancing act. Too thin and you don't have enough pressure to keep parts on a hydrodynamic film and end up in the boundary layer which will cause wear. Too much viscosity and you don't move enough oil thru parts and you start heating up bearing surfaces and have issues keeping high sliding friction loads from scuffing.

Regular maintenance is probably more important as long as your favorite oil is somewhere between too thin and too thick for the particular engine. Anything in between changed on the regular is the "best" no matter who's name is on the bottle. And who's name is on the bottle has little to do with whats IN the bottle most times anyway.