Thoughts on Oil Stuff, Cam Wear, and Additives

[Hippie]

Todays lower "zinc" oils and solid lifter cam wear.
Zinc or phosphorous or ZDDP or zinc dialkyldithiophosphate--the main antiwear additive in motor oils has been reduced several years ago from 1000-1100 parts per million to the current limit of around 800 ppm because the lower levels of ZDDP, or we can call it zinc, is shortening the life of catalytic convertors.
Since the zinc reduction there have been problems with cam lobe failure on some older engines--particularly high performance engines with high valve spring pressures and/or high lift cam lobes with a good and significant contact area.
Zinc, actually it is the phosporous in the zinc compound, is a heat activated anti-wear agent forms a "last ditch" temporary glass-like layer on the metal of extreme pressure contact points such as mentioned above to prevent metal-to-metal contact. The additive (ZDDP) is consumed in the process. The ZDDP levels tend to go down as the oil remains in service for longer periods.
Although ZDDP protects all moving parts in an engine, the cam (solid) lifter interface is the most likely failure point. This interface is the one place where we find steel sliding on steel at such a highly concentrated point of spring and inertial pressure.
Modern consumer car engines normally have roller type lifters rather than solid dittos that ride the cam, and if they don't, it is because they use a low mass overhead cam valve train with much less inertia and low valve spring pressures. These tend to circumvent lobe failure conditions with today's lower zinc oils. some concern has been raised about our old ACVWs with their solid lifter, push rod valve trains.
There have been some cam lobe failures out there with these engines and some folks are using high doses of break-in additives in their oil to try to avoid this.
Personally, I think there are some qualiy issues in the parts themselves.

The current ILSAC GF-4 API SM oils with 800 ppm ZDDP have been tested on solid lifters engines to 600 lbs. lifter pressure without scuffing. Of course, that's in an engine with healthy cam/lifters with good and significant surface area.

I don't know how that pertains to an ACVW engine with it's higher operating temperatures and smallish lifter faces, but it leaves me in doubt as to whether any pushrod engine without a high performance valve train needs any ZDDP boost past intitial break-in--if even during break-in.

Once again, I think there are some quality and metalurgical problems out there that may be getting blamed on the newer lubricants.
In fact, in order to meet the newest (GF-4) requirements, oils have to pass the Sequence IVA test in a Nissan, solid lifter OHC engine.
Now before you disregard this due to the fact that this is an OHC engine, know that the maximum cam lobe wear requirement has been lowered from from 180 microns to 90 microns. This is the total wear allowance added up from five spots on each lobe, and all the lobes' wear is then added. This is a severe service 100 hour test.
The previous 180 micron standard was for oils with an average of 1100 ppm Zn, as opposed to the current 800 ppm.
There is more to wear than ZDDP content.
The newer oils have an evolutionary improvement in base oil characteristics to increase film strength and prevent metal-to-metal contact in the first place, as well as improvements in other anti-wear additives such as advanced molydenum compounds and borates.

Having said all that, I have used "zinc" additives--but with caution.
Extra ZDDP will override the detergent/antacid package the add pack has been balanced with. This will shorten the possible oil change intervals as the oil becomes increasingly acidic and corrosive.
ZDDP itself, although an excellent and very polar (Polar is good. It helps the oil cling to the metal.) anti-oxidant, will cause bearing corrosion problems when the level gets much above 1400 ppm.

If/when I have used these additives, it has been to raise the ppm no more than 100-200 ppm.
In Lucas TB Zinc Plus, this amounts to about 1 oz per 6 quarts of oil, and for STP, one bottle per 4-5 quarts of oil.
I believe the Redline additive is about half as strong as the Lucas brand--if I recall correctly, Redline was about 17,000 ppm and Lucas is 38,500 ppm. STP runs just under 2000 ppm.
BTW, I don't worry too much about red (lower viscosity 4 cylinder formula) vs. blue bottle (regular) STP even though the viscosities are about 110 and 250 cSt @ 100 C respectively--since the ending viscocity of two fluids tend to the thinner fluid according to a logarithmic formula, there is not much difference in end point viscocity of the oil between the two when used in recommended proportions.
Added to 5W-20 with a cSt viscosity of 8.4 @ 100 C at a ratio of about 6:1 oil to STP, the end viscocity ends up about 10.2 and 10.9 for the two STP types according to the Widman International viscosity calculator. Those correspond to a XW-30 at driving temperatures.
A lot of VW guys buy extra zinc oil to play it safe--and that's not a bad idea. Not sure if it's necessary, but not a bad idea. But Higher zinc oils like Brad Penn, Royal Purple, Valvoline VR-1, and some of the non GF-4 SM oils in 10W-40 and 20W-50s are formulated from the git-go for the higher zinc levels.

Have a nice day.

Glossary:
Base Oil = Or base stock, is the oil before any additives or modifiers are added by the oil manufacturer before bottling .
OHC = Overhead Cam. Reduced inertia of this valve train allows lighter springs to be used to hold the valves closed compared to a traditional OHV engine.
Polarity = The electrical asymmetry of a molecule that tends to cause electrostatic attraction or “clinging” characteristics. This effects how well the oil film is retained by the metal.
Pushrod OHV engine = Cam is located inside the engine rather than in the head. Due to the relatively high inertia of the pushrods connecting the lifters to the valve rockers (actuators), heavier valve springs must be used causing a higher load on the cam to liter surface than on an OHC engine—all other things being equal.
Zinc = Zn, and for our purposes, is used interchangeably with ZDDP, ZDP, and Phosphorous.


Links:
http://www.carbibles.com/engineoil_bible.html
http://www.bobistheoilguy.com/
http://ferrarichat.com/forum/faq.php?s= ... oil_basics
http://www.lnengineering.com/oil.html#Z14
http://www.bobistheoilguy.com/forums/ub ... 45&fpart=1
http://www.swri.org/4org/d08/GasTests/I ... efault.htm
http://www.zddplus.com/TechBrief12%20-% ... eak-in.pdf
http://www.zddplus.com/TechBrief2%20-%2 ... 20Myth.pdf
http://www.zddplus.com/TechBrief10%20-% ... Stocks.pdf
http://www.swri.edu/4org/d08/GasTests/home.htm
http://www.rohmax.com/rohmax/en/custome ... lmixtures/

(see Bob Orlee Oil Myth)
http://forums.pelicanparts.com/showthread.php?p=4251192

[Amskeptic]

I agree that the metallurgy of the lifters themselves is a more likely cause of failure.

Our main and rod bearings are very soft lead babbit on copper. I don't do high zinc for anything more than assembly and it is gone after the 20 minute break-in. (TRW Cam and Assembly Lube, a nice red clear liquid that does not run off)
Thank you for your post.
Colin

[Hippie]

Ya. TRW is good sticky/slick stuff.

[vdubyah73]

I know, directly, of 2 different guys that put heavy duty diesel oil, which has a high zinc content, in their Ford pickup trucks with gasoline engines. Their oil pressure dropped to very low normal and never returned to what they had before trying the diesel oil. One guy went so far as to replace his oil pump with no luck. This happened 20 years or so ago, they thought they were being smart by taking the dregs out of the 55 gallon drums that the DPW was discarding when the pump wouldn't draw any more oil out. The second guy was warned about what happened to the first guy, but didn't listen. I agree with what Colin said about bearings. Zinc will ruin bearings if too much is added. Chico of CPR engines used antique, resurfaced, Norris racing lifters in my 2275 w/E120 cam, dual Chevy springs, with ratio rockers, I use Castrol 20-50 and have had absolutely no problems. In my 2.0 Bus engine I got a hold of new/old Febi's made maybe 15 years ago, use 10-30 Castrol with no problems in 20K. I think it's cheap metallurgy also.

[Hippie]

And no doubt what they got in those 55 gallon drum dregs was a crapload of additive fallout (reason why I shake my oil bottles) and possibly some dirt too. Yow.

I have no problem boosting ZDDP a little to the standard of oil we were using up 5 years ago if a fella is really worried, but some of these otherwise knowledgable guys (on TheSamba, for example) are running high performance engine break-in levels all the time. Yow again.

[spiffy]

Yup, a ton of hype out there on the ZDDP. I think it is partly due to the "snake oil" factor.

X2 on a great post.

[RSorak 71Westy]

This issue is really critical during cam break in....Another issue in the rash of cam/lifter failures is that most all OEM's dont use flat tappets anymore and the companies that made them have gone under....and the replacements are not up to snuff. Comp cams offers nitriding on new cams and I think it is worth every penny. Makes the cam surface much harder. I'n planning on putting a new cam in my 528 Hemi soon and am switching it over to a roller partly for these reasons.

[Amskeptic]

This issue is really critical during cam break in....Another issue in the rash of cam/lifter failures is that most all OEM's dont use flat tappets anymore and the companies that made them have gone under....and the replacements are not up to snuff. Comp cams offers nitriding on new cams and I think it is worth every penny. Makes the cam surface much harder. I'n planning on putting a new cam in my 528 Hemi soon and am switching it over to a roller partly for these reasons.

I have had discussions with AVP and Bus Depot and the conclusion is Please Put Up With The Febi Lifters as they are erring on the side of self-sacrifice to spare the cam. I am good with this. If the lifter accidentally out-hardens the cam lobes, you will have prematurely worn cam lobes that necessitate the teardown of the engine. Thus far, I am on my second set of Febi lifters @ 88.00/set (with most recently the replacement of only four of the second set) and 165,000 miles on my lowly Bus Depot replacement camshaft. It is easy enough to replace lifters on the Type 4 engine, so I am well-enough satisfied with having to do a la carte lifter replacements from here on out.
Colin

[spiffy]

If you want to take the guess work out, go for the Udo Becker tool steel lifters for the type 1.

[hambone]

German lifters are still available as well for type1.

[Hippie]

...and 165,000 miles on my lowly Bus Depot replacement camshaft...
Colin

And this mileage is within the time frame (post early 2004) with the current "zinc" levels, I assume?

X2 on a great post.

Thank you.

[busman78]

Great write up. I use the Torco MPZ on the cam/lifters during assy and a bottle of EOS with the oil on start up. After the 20-25 run up all the oil & additives are dumped with the filter and screen. From then on the engine is on Castrol 20-50. So far no worn lifters or can lobes.

[Hippie]

I wish I could find the pdf.Bulletin that Valvoline officially published in 2008 to quell concerns about lower ZDDP.
They essentially say to do the same thing as what you do.
Use a break-in additive during break-in if needed, and then go to regular oil.
It disappeared off the web, but I think i have a copy somewhere if you need it.

[midatlanticys]

this the one?
http://goldengatev8.org/tips/2008-003a.pdf

[Hippie]

That's it. Thank you.
And I remember now it doesn't mention break-in additives--that was in a you-tube video excerpt where they had a Valvoline rep. on a hot rod building show.