Lets talk about zinc, engine oil and flat cams

[SirRobyn0]

So in another thread there is some talk of flat cams, wiped lobes, which lead me to zinc and engine oil. So here is the thing. At the shop when we are working on an older car or truck we pretty much put in whatever flavor of motor oil the owner wants and if he or she doesn't want anything specific we just pic something that is appropriate for the engine. Generally speaking we don't use a high zinc oil, but we do keep hyperlubes zinc additive on the shelf for anyone who requests it. I do feel that hyperlube makes good products so I'm comfortable with that, but I've begun to wonder if every vehicle we see with flat tappets should get the additive rather than only when the owner asks for it. Additionally I have just been running regular dino oil in my 350 without any additives. As we all probably know oil manufactures have greatly reduced zinc content in motor oil starting in the mid-90's so that would be the reason an additive might be needed. Of course the downside is when zinc is burned is rather hard on cat converters, and zinc can aid in deposit build up in the engines. Which could possibly mitigated with regular oil changes, but it's still a concern. Zinc's primarily job is to hang around on metal surfaces to provide an additional barrier particularly at start up. In which case could the standard hyperlube additive, you know the thick stuff, could that be an acceptable alternative to zinc without the downsides? Your thoughts please.

 

[75gmck25]

Mobil 1 15w50 with high zinc (1200 ppm) and phosphorous is sold at almost all parts stores, and it’s the same price as other synthetics. It also goes on sale at the same time as all the other Mobile products. I figured it is cheap ”insurance” against cam wear.

Bruce

 

[SirRobyn0]

@75gmck25 Bruce, I can't disagree, except that for someone like me with old never rebuilt motor full synthetic might not be the best idea. I'll have to see if they make conventional version. I know Valvoline makes a conventional high zinc / phosphorous oil.

 

[Shorty81]

I use Shaeffer Supreme 7000 10w30 synthetic with extra zinc. Got to keep cam healthy.

 

[bucket]

I just run standard oil in all my engines. The wiped cam I mentioned in the other thread was due to other issues. That was the third cam that failed in that engine. Proper break-in was done, all precautions were taken and high zinc oil was used. The failures were likely due to unknown valve springs installed by the PO. Besides that, no cam failures here and never had any come in when I still worked at the shop. No flat tappet type failures anyway.

 

[SirRobyn0]

I just run standard oil in all my engines. The wiped cam I mentioned in the other thread was due to other issues. That was the third cam that failed in that engine. Proper break-in was done, all precautions were taken and high zinc oil was used. The failures were likely due to unknown valve springs installed by the PO. Besides that, no cam failures here and never had any come in when I still worked at the shop. No flat tappet type failures anyway.

Ya see that's the thing. I can't remember the last time I saw a wiped lob in person. It's been probably 20 years or so. But I keep hearing talk of it, not just here on the forum but from friends at other shops and they as well as people here seem to think high zinc oil or additive is needed. I never really put much thought into it before now, and maybe at the shop the thing is to just let folks know the additive option is available and I keep doing what has always worked fine for me, which is basically dino and regular changes. We'll see what else is said.

 

[DoubleDingo]

I said this in another zinc-related thread. I am a firm believer in using the proper oil and additives for the break-in period, and heat cycles, long heat cycles. My thoughts are, that most likely it's the engines in trailer-queens that have wiped lobes. For us that run our trucks for more than 20 minutes at a time, and change the oil often, not waiting for it to turn black and glittery, then we'll be fine, whereas, the trailer-queen owners will wipe more lobes due to lack of long heat cycles even if they change the oil often.

For the record I use Valvoline Conventional 10w30.

 

[80BrownK10]

Right now I'm running CJ4/SN 15w-40 tractor supply company oil. Diesel oil has higher zinc than most of your normal motor oils. This is the older oil spec than the most current one. And has a higher zinc level as I understand as the current I guess Ck oils

 

[peats]

i had a 350 simply run out of power due to cam wear. swapped that motor for a 406 sb. changed the cam and timing chain and installed the 350 into my 81 c 10, 14k miles later running great. rotella 15-40 and zink additive with every oil change. not taking that chance again.

 

[Ricko1966]

I stated in an earlier post cams are work hardened, that's why those first 20 minutes are so important, that new cam is still soft. The ZDDP was in the old oil for a reason, not because some chemist was bored it's still in the diesel oils, again not because someone had some extra DZZP laying around.I"ve seen to many flat cams at work, I can't tell you why they went flat,IDK.But if profesionals smarter than me say DZZP is the common denominator.And when I call Shelll oil and they say yes run it, and not just to make more money, because the guy told me just run Rotella T4 it's got plenty DZZP. It's dino oil and it's cheap. And when I call STP to find out if they lowered the DZZP formula on their oil additive, they get all dodgy about it. Does STP still contain the origona l formula of DZZP? Yes STP has DZZP.Not what I am asking and here is why.Now, does STP have the same amount of DZZP it used to have? Yes STP has DZZP in it. Does it have the same amount? Yes STP has DZZP on it. Well now for my opinion I think the reason everything is roller now is because the manufacturers recognized this situation long before we did. As for proper break in then forget it I do not agree, break in is the most important 20 minutes of a cams life but it's not the end of the story,but that's just my opinion, based off my observations.Its cheap insurance, just like a seat belt hopefully I don't need it but I wear it just in case. And I don't just pick which days I wear it.Okay, sometimes I pick and choose,I don't need after a few beers, that's freaking .brilliant.