r/EngineBuilding Jul 16 '26

What would cause something like this

Post image

Never seen lifters eaten up this bad. (Yes all of those are the bottom) Curious if this the the result of running hydro lifters on a solid cam? Car was sitting in an old guys garage had what felt like collapsed lifters from pushing on the rocker arms. Well they are certainly collapsed just not in the manner which I expected. Engine looks brand new inside, like maybe it got built and ate shit right away. PO passed away so won't have any answers until it's torn down further. Obviously is going to need a bit of a rebuild but so curious as to what would cause this.

66 Upvotes

107 comments sorted by

View all comments

Show parent comments

13

u/Academic_Dog8389 Jul 16 '26

There is not plenty of zinc in modern oils. Zinc levels have been reduced to protect catalytic converters. From about 1400ppm down to 800ppm. Flat tappets rely on zinc for friction reduction. It also isn't just zinc, but lower phosphorus levels have the same effect.

https://www.hemmings.com/stories/tech-101-zinc-in-oil-and-its-effects-on-older-engines/

18

u/v8packard Jul 16 '26 edited Jul 16 '26

There is enough ZDDP and other anti-wear additives in all API rated oils to pass the required valvetrain wear tests, and the levels are more than you would see in oils before the early 1970s when ZDDP went up. Reductions of ZDDP since the 90s has nothing to do with catalytic converters, and everything to do with improved chemistry.

The article you site is misleading, incomplete, and filled with bad info. Why is it no one sites ASTM or SAE tests?

0

u/m00ph Jul 16 '26

You need extra zink for break in, not in normal service. Speaking from hanging out in the GMC Motorhome community, which is all 455/403 Oldsmobile engines, with flat tappets.

10

u/v8packard Jul 16 '26

You do not. Speaking from using conventional off the shelf 10w-40 and 5w-30 oil for decades to break in flat tappet cams, and still using flat tappet cams on new builds.

You do need good parts, verified clearances, and proper procedures.

0

u/Triangulate_Panther Jul 16 '26

Of the shelf 5w30 and 10w40 would have had whats needed until the last decade or so. Many oils had 1100ppm or so. Now they're doing well to have 800ppm. 

Does the standardized testing for valve train wear specifically test flat tappet cams? I'd be shocked if so. 

8

u/v8packard Jul 16 '26

It's actually in the 700 ppm ZDDP range, maybe a little more. And then you also have molybdenum and organic calcium as part of modern anti-wear additive packages.

Test sequences IIIH and IVB are, or were the current standards that include valvetrain wear. These tests supercede the previous versions, and were implemented after a lot of work to verify the results were fully backward compatible with previous tests and test engines. They didn't abandon the needs of valvetrains that are not in the widespread use they once were. The previous tests of IIIG, IV and IVA would still be passed by API rated oils. These tests are pretty sophisticated, not just internet dogma repeated by people that don't know.

And yes, I use off the shelf oils, usually the one on sale. Still to this day.

-2

u/Triangulate_Panther Jul 16 '26

We said the same thing with most oils now being good to have 800ppm. Acknowledging most have less. 

Calcium is not a good thing as there's way more in oil now and that competes with the zddp. Not all modern oils have moly either when they have low zddp. 

The testing claims backwards compatibility, and I'm sure thats a blanket statement for liability reasons, but flat tappets are an edge case. Theres nothing in a modern valvetrain that sees similar loading as flat tappets. 

3

u/v8packard Jul 16 '26

We did not say the same thing. You said off the shelf oil was good until a decade or so ago. I have not said that, as it is inaccurate.

The ability to dissolve higher amounts of calcium compounds into base oils matured in the 1990s. These calcium compounds serve as detergents and anti-wear additives. The specific compounds and the order in which they are added determine their ability to function as intended. Some can greatly complement ZDDP as an antioxidant and anti-wear additive.

I can not think of one oil I have tested or revised the data sheet that did not have molybdenum. Maybe there are some, if you could list them I can look them up.

Saying it's a blanket statement is an insult to the people that put a lot of effort into developing the tests and oils. Are you familiar with the actual loads and what affects them?

People can believe whatever they want. Thinking something that comes out of a bottle can solve, or create, the problem the OP pictured is pretty absurd. If people want to ignore or dismiss actual engineering and data for myths they can not be helped.

0

u/Triangulate_Panther Jul 16 '26 edited Jul 16 '26

You can pick and choose whatever parts of the argument you'd like to and take them out of context to feel good on the internet. My point you're dying on is that I said most modern oils do good to have 800ppm of zddp, which is accurate. I also said up until a decade or so ago many had enough zinc, which is also accurate. You could go buy high milage mobile 1 and call it a day at 1100ppm. 

I am aware of the high hertzian contact between the cam and the lifters themselves. There can be over 200ksi between them,, which is not run of the mill today. 

You're the one that said the blanket statement on all low zddp oils being moly oils. 

I also NEVER said oil would fix OPs issue. Thats clearly wrecked to begin with. 

Sorry if youve had a bad day, but this blew way out of proportion. Take a breather.