[mean_1le]

How necessary is a 'high-zinc' engine oil (such as zrod) for a cammed motor, as compared to a regular full synthetic?

[GreyGhost702]

Wildly up to whose opinion you value the most. Everybody’s favorite shop/tuner/machinist has been in the business a bijillion years since the dinosaurs first pissed 100 octane in a leaded cup. I asked my first engine builder this same question on an engine build that I was spending “a lot of money” on. He said all the tolerances were factory, just because the parts are forged don’t mean shit. Run what it says on the oil cap and/or in the owners manual. With the exception of track days, I have run Supertech 5w30 in virtually every application. I did get spooked into 0w40 for this car for a while. But oil analysis doesn’t lie. There’s no special voodoo going on in Mobile 1 or Penzoil to justify the cash flogging you’ll get when you run it.

As far as that break in oil it’s still mythical in my opinion. The first 1000 miles with a zinc heavy oil are going to do what for the cam/lifters that a regular oil won’t? Heavy zinc will definitely play havoc on catalytic converters. My current engine build will be 5w30 for first start, straight dino oil. Get the rings set and everything hot. Dump it and 5w30 synthetic the rest of its life, bar any exception if I put it on the track for some reason. The 10 second WOT pulls on the street are never gonna justify running specialty oil. And don’t change the oil when the computer tells you. Change it by miles or as needed. Such as, after a 1,000 mile road trip where the engine never shut off except for gas. Could be a good enough reason to change it early. Keep a “good” oil in it that makes you sleep easy at night. If your cam and lifters start spalling, it’s not going to be because you didn’t run a heavy zinc oil and appease the car gods with a blood offering. Such issues are hotly debated and I do lean toward the push toward synthetic oils, and sub-par metals being used in today’s lifters and cam cores. There’s a lot of pros to synthetic oil, and some cons. We all know the pros and cons for crappy metals and construction methods.

Good luck with your quest for a solid answer on this one!

[FlukeSS]

My engine rebuild: I was told the engine was rebuilt with looser tolerances than stock. And as such I should use real oil thicker oil than synthetic recommended. He did say however there are some types of synthetic that can be used, but it isn't the GM recommended. My shop who owns 1500 hp cars said they use this particular oil in all their race cars.

My engine was rebuilt with starter oil of 15W40, then told me after 1500 miles switch to 10w40 for what I use the car for. Daily + Strip use. The only other stipulation I was told was to let the car warm up, because of the thicker oil and looser tolerances before I get on it. And, not sure if it matters but my engine has upgraded Delphi Lifter set.

My shop said the main reason to use real oil instead of synthetic is because of the known lifter issues these cars have. They tend to go out faster with synthetic oils.

But as GreyGhost stated: Believe what you want. I just know after what I spent to rebuild my engine if something goes wrong it ain't because of the oil as I did what I was told.

[Germansheperd1]

Originally Posted by mean_1le

How necessary is a 'high-zinc' engine oil (such as zrod) for a cammed motor, as compared to a regular full synthetic?

In a roller engine it’s not a big thing like said run what is on your oil cap. In a flat tappet hydraulic engine it is a big deal to run a high zinc oil especially with a bigger cam.

[Baddawg53]

I can only go by my own experience, and that was when I started using high zddp oil my samples started showing less wear overall. I switched from 0w-40 mobil 1 to 0w-50 mobil 1 racing oil. Car was heads/cam/FBO. Unfortunately I still spun the 7/8 rod bearings but due to all the previous wear I think all I did was extend the life of it a bit. I'll be using only a high zddp synthetic oil after my new engine is broken in.

[GreyGhost702]

Originally Posted by Baddawg53

I can only go by my own experience, and that was when I started using high zddp oil my samples started showing less wear overall. I switched from 0w-40 mobil 1 to 0w-50 mobil 1 racing oil. Car was heads/cam/FBO. Unfortunately I still spun the 7/8 rod bearings but due to all the previous wear I think all I did was extend the life of it a bit. I'll be using only a high zddp synthetic oil after my new engine is broken in.

There are a number of reasons and series of unfortunate events that can lead to a spun rod bearing. I can't say that it's correlation, but I read more on bearing failures in factory engines than rebuilds, particularly forged. To press on this further, most people that go with a forged build tend to run an aftermarket oil pump (billet gears and/or higher volume/pressure). Oiling issues probably rank among the highest for cause behind a spun bearing. High RPM/load is another contributing factor. And what do people like to do to these cars right out of the gate? Cams. Intake manifolds. Boosting. All of these mods involve taking the engine to higher than designed RPM and loads. Driving at high RPM/Load for longer periods as well. Long story short, I highly doubt your spun bearing was the result of using a regular synthetic oil.

No argument a high ZDDP content oil will likely provide better anti-wear protection than a more common zinc content oil under harsh conditions. It doesn't guarantee immunity from our favorite failures. I'm only saying, most of your normal oils will provide more than adequate anti-wear protection for the average street racer, and definitely daily driver. I'd never discourage anyone from running what they feel necessary or what their builder/tuner asks them to run. Just for example, you can readily find lab analysis' for both SuperTech (most consider to be a budget oil because of who sells it and spends nothing on marketing it, instead of who makes it) 5w30 and Mobil 1 (who spends a shit ton of money on marketing) 0w40 and the Zinc levels are similar across the board. In fact, only Mobil 1's Racing oils truly have higher than "normal" zinc levels (in the Mobil 1 lineup). The 0w40 Supercar oil is not among their Racing line. In fact, most of the data supports that it's a watered down version of the ESP 0w40 Dexos 1. And if you don't think GM won't put wear protection in the back seat over its emissions ratings, think again. What's worse is they rebranded the ESP bottle as "Supercar" for the 'vette and put a nice marketing markup on the bottles. Now that we're talking rabbit holes here, I may have to do some digging on the 0w40 Euro oil. Could be missing out there. Would have to pull up the GM requirements and compare it. If it's good enough for the Euro engines, it should be great for a domestic. Don't hold me to that statement, I'm just thinking out loud here.

Here's one of my favorites, although don't take it as gospel, while his tests and methods are solid, there are a few key elements missing such as molecular shear. There's really no garage test for that. It would need to be done in a high tech lab that basically crush an oil molecule while conducting the shear test.

https://youtu.be/zwqt5vI0o1A?si=LAshhRlLbyp8qKJI

I digress to my original position though, as far as break-in oil and oil for normal use (non-track) I've never found a reason to need more than a good oil, and good oil change habits. I don't believe in waiting for the car to tell me when to change the oil. The dipstick, odometer, or calendar will tell me. Also how the engine has been used on its current oil feeding.

[GreenZLE]

At 2008 or 2009's SEMA, I was fortunate enough to attend a seminar put on by Torco which was also attended by guys from Spectro. I also stayed after and we all had sort of a small group discussion.
Several things I learned:
1. So called synthetics are oil pumped out of the ground, they are just hyper refined to a level that the government allows them to be called synthetic
2. True synthetics are ester based oils and back then, the Torco true synthetic was about $17/qt
3.ZDDP is an anti scuff additive that needs to be at least 1200ppm to do much good. Its critical for non roller type lifters/cam lobes. It also aids in piston skirts not scuffing against the cylinder walls.
4. At the time at least, there were no regulations governing the carrier oil that was used to blend the additives into the oil. For example "synthetic" brand A could use an additive package that was blended into a non synthetic oil and then added to the base which did not affect the status/claim of the base oil being "synthetic".


Modern pistons have anti scuff coatings on the skirts and roller cams dont really need ZDDP. Its more important that they dont loft and hammer the lobe. ZDDP's main benefit in a modern engine might be if the engine ever oil starves briefly, but thats just my guess.

[GreyGhost702]

Originally Posted by GreenZLE

At 2008 or 2009's SEMA, I was fortunate enough to attend a seminar put on by Torco which was also attended by guys from Spectro. I also stayed after and we all had sort of a small group discussion.
Several things I learned:
1. So called synthetics are oil pumped out of the ground, they are just hyper refined to a level that the government allows them to be called synthetic
2. True synthetics are ester based oils and back then, the Torco true synthetic was about $17/qt
3.ZDDP is an anti scuff additive that needs to be at least 1200ppm to do much good. Its critical for non roller type lifters/cam lobes. It also aids in piston skirts not scuffing against the cylinder walls.
4. At the time at least, there were no regulations governing the carrier oil that was used to blend the additives into the oil. For example "synthetic" brand A could use an additive package that was blended into a non synthetic oil and then added to the base which did not affect the status/claim of the base oil being "synthetic".


Modern pistons have anti scuff coatings on the skirts and roller cams dont really need ZDDP. Its more important that they dont loft and hammer the lobe. ZDDP's main benefit in a modern engine might be if the engine ever oil starves briefly, but thats just my guess.

I highlighted that 1200 ppm. I've read similar, but also that it's mostly older engines in the classics that demand that high zinc content. I assume mostly due to flat tappets being used. The majority of Mobil 1 Racing line of oils hover around 1200-1400ppm depending on which oil you look into. Most of the higher end oils seem to target this area as well, there are a few break-in oils that really kick it up into the 1700ppm+. Of course you can always buy ZDDP additive and make "any" oil a high ZDDP oil, I say this not knowing specifics of base oil requirements for these additive packs. Most of your off the shelf common oils range from as low as 400ppm to 900ppm. Most of the SuperTech oil analysis' I've come across all range in the low-mid 800ppm. Surprising to me, Penzoil has the higher shelf range in tests showing high 800-900.

Again, I'd never try to sway anyone to use one oil over another, I think it's important we all educate ourselves and share knowledge/experience, and most important is to first meet the manufacturer's minimum recommendations, and hopefully exceed them.

I'd been debating on making my car a Torco queen, in regards to their octane boosters. Unfortunately, west of the Rocky's we don't get 93 octane options, and E85 is rare as well. Rare enough, in my opinion, I wouldn't tune the car for dependency. But Torco looks like a nice deal to raise the octane up to 94-95 octane without breaking the bank. And IMO it's easier to roll with a couple bottles of octane booster in the trunk, than it is to hunt down an E85 pump whilst burning 30% more of your MPG's getting there lol. I loved having my old Mustang on the corn, but I lived 5 miles from a pump. From where I am now it's an hour drive at least.

Sorry OP, this one did get a little sideways. Hope some of this has filled in some of the question holes regarding your cam swap.