Zinc been taken out of Rotella oil & other diesel brands

[L78CHEVELLE]

Just had a long talk with my flathead engine builder, and he tells me that Shell Rotella has taken out the zinc. He told me not to run my flathead engine without the zinc oil. It seems some of the new diesel engines have converters and can not use the zinc oil. What gets me is no company has told us that. I buy the oil by the case and now have 17 gallon of no zinc oil that I must ad zinc to. Does any one know if Mobile One synthetic still has the zinc in it? How are the rest of the flathead owners dealing with the zinc removal?

[oldford2]

Did your flathead engine builder explain to you why a flathead needs zinc?
John

[Old Henry]

I add ZDDP.



Cheapest here: http://www.eastwood.com/ew-zddp-oil-additive-4-oz.html

Reports of tests that I have read conclude that zinc does not need to be added to flathead engines because of the low valve spring pressure. I still use it just in case it helps. I also add it to my transmission, differential, and steering box.

[flatjack9]

Did they take it out or just reduce the amount of zinc?

[Ken/Alabama]

I wonder if motor oils from the 30s and 40s had any zinc in it at all . Flatheads don't have a lot of spring pressure compared to the overhead valve engines . This is of coarse just my opinion and when it comes to oil ,everyone has one .

[Steve Staysko]

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[flatjack9]

Originally Posted by Ken/Alabama

I wonder if motor oils from the 30s and 40s had any zinc in it at all . Flatheads don't have a lot of spring pressure compared to the overhead valve engines . This is of coarse just my opinion and when it comes to oil ,everyone has one .

Actually it is a combination of zinc and phospherous. It was introduced in the 40's and by the 50's was up to around 300 ppm. This increased to 1200 parts by the 80's. Since then it has been reduced to about 800 parts, still way more than what was available when our engines were being produced. Even overhead valve flat tappet engines can survive with 800 parts after breakin, unless your running a high lift cam with huge spring pressures. For break-in, a racing oil should be used as they still have the higher additive level.

[L78CHEVELLE]

My engine builder tells me the zinc provides oil flow to hot spots within the engine. He specifically mentioned the motion of the rod bearings needing the zinc. He told me the older camshaft engines need the zinc additive. He had a 1965 Chevy truck engine there with less than 50 miles on it that was rebuilt by another shop. The camshaft in that engine was worn out. The camshaft manufacturers that sell non roller cams insist you do the zinc additive or you will void the warranty. I posted this ad to find out what my fellow flathead engine owners are doing with their cars, and to make flathead owner's aware of the change in the diesel oils.

[J and M Machine]

I posted this ad to find out what my fellow flathead engine owners are doing with their cars, and to make flathead owner's aware of the change in the diesel oils.
"Quote"

You're correct as the amount of zinc has been reduced in diesel oils. However according to published reports there is still the proper amount of zinc in Valvoline VR-1 oil.
I typically recommend Brad Penn brand oil to our customers as we have a dealer in our local area.

The zinc is for all crucial wear areas in the V8 anywhere there's bronze bushings or metal to metal contact.

[rotorwrench]

Oil changes were recommended a lot sooner back in the L-head days. They didn't use zincdithyodialkylphosphates (ZDDP) but they did add near 250 ppm of a zinc based additive and 200 ppm of a phosphorous based additive back in the 50s. Zinc phosphate is a must for overhead valve engines with high spring presures such as were produced from the mid 50s clear up into the 90s. Flatheads not so much. The levels of ZDDP in motor oil should not go over 1200 ppm for a gasoline engine in any case due to the protective levels of the oil start to degrade if the levels get too high so don't get carried away with adding the stuff in. Follow the additive instructions to a T.

Oils with API SG & SJ levels of ZDDP are still available from specialty producers like Lubriplate, Penrite, and maybe a few others. Some additives are marketed as ZDDP and have no zinc phosphates at all so you have to do your research before purchasing them if you want to boost the new API SM rated or later stuff.

[Merc Cruzer]

I get mine at the local NAPA store.

[Ol' Ron]

The answer here is to use a synthetic oil. 5/20 for a new engine would work just fine, This would reduce pressure (Which is a good thing) and increase flow, (which is a good thing) and run cooler (which is a good thing) OLi changes every 20,000 miles (which is a very good thing). Any questions??

[Walt Dupont--Me.]

Well, I just bought 5 quarts of Rottela 15-40 today from VIP and it still had zink Cl-4 in it. Walt

[paul2748]

You better get a new mechanic because he does not know what is is talking about. This has been confirmed with Shell.

The ZDDP (zinc combination) was reduced somwhat about three years ago, but the ZDDP in it that is more than enough to protect any flathead ever built (except maybe for a ultra high performance racing engine). Ditto with most oil that has a 40 weight or higher rating.

[flatjack9]

Just typical of what you hear when something is changed. The sky is always falling.

[woodypecker]

The failure that everyone is worrying about is wiped cams on flat tappet engines. A few things have happened lately as follows: the ZDDP in oils have been reduced to protect catalytic converters, there have been counterfit foreign lifter parts on the market, and a lot of people are building high performance vintage engines with high lift and high spring pressure. Ressults are lots of cam failures. Everyone is blaming different things. The high lift cams I had in my youth I blew the engines long before they wore out. I use the ZDDP as an insurance policy even though I really so not think it is necessary. I am interested in everyones opinion.

[Jack E/NJ]

Ol' Ron>>>5/20 for a new engine would work just fine, >>>

Ditto. Been running 5W-20 synblend without drama in a re-freshed 21-studder for more than 2 years. That's what Ford recommends nowadays. 8^)

Jack E/NJ

[Ol' Ron]

Modern lubrication is far superior than the old stuff ever waz.

[296 V8]

What’s to worry about
Add zinc and use up the oil you have … then buy new oil accordingly.
If it turns out you didn’t need zinc … oh well you lost a few dollors but not a cam shaft and a bunch of work.

[G.M.]

Use Valvaline Cummins Blue 15/40. It has all the good ingrediants. Check out the attachment. G.M.