Inliners International Forums General Discussion Engines Interesting read on engine oil/ zdp

I know this topic has been beat to death several times but this is an interesting read:

http://www.steelsoldiers.com/index.php?name=PNphpBB2&file=viewtopic&t=16734

Has anyone on this board actually had an oil-related failure before (not a failed oil pump or leak, but something that failed because of the oil you used?)? *pauses for a few seconds* ... I didn't think so

Pennzoil, Quaker State, Amsoil, detergent, non-detergent, multi-vis, straight vis, Ford, Chevy... this argument will not actually ever be resolved. Use the oil you want.

yes, i have had a failure. it was a 396 motor in my dads car with a fresh rebuild. cam ate a lobe after 2 years. flat tappet cams need the ZDDP additive.

all the newer oils are designed for engines with roller cams. not our old designs and flat tappets. i have switched to shell rotella, but now even it has had 1/2 of it's good stuff removed. i now add a little GM EOS to the oil at each change. even EOS is is discontinued by GM for EPA reasons.
there are now begining to be a few oils being released for older engine designs.

by the way that was a interesting read, but way off! tom

Yes, we had a camlobe go flat after 900 miles. Only one went clear flat, two more were starting to go. We know of two more cams that did the same thing. Joe

Very interesting!

Should I be using the "Shell Rotella" oil in my 1975 292? Right now, I am using Valvoline 10W-30.

The motor has a rebuild 8 years ago, bored .040,
crank .010. It does blow some blue smoke when you
rev it up but not when idleing or cruising. Probably a valve that never did seat correctly. It has done that since the rebuild. Great compression across the cylinders.(125lbs) Did a leak down test and it was good.
Is there any way to solve the smoking problem? I was told that "umbrella seats" would solve the problem of a little leak back. These can be installed without pulling the head if you have the tool to "air up" the cylinder to keep the valve from dropping.

RapRap
1940 ChoppedChevyCoupe

chopped, you need to install the positive seals on the valves. this requires machine work to the guides to accept them though.
the oil is probably being sucked into a intake valve down the guide. if you don't allready have umbrella seals, then i would get them installed. no machine work required for them. tom

I had a 454 in college which was on it's 3rd camshaft. I don't know that it was due to oil. I pulled the valve covers once and found that not all of the pushrods were rotating so I am assuming that it never developed a good wear pattern. Eventually, the timing chain went out so I wonder if it was all poor quality parts. BBCs are supposed to be notorious for eating camshafts.

Tom, what part of it is way off? His data, his analysis, his conclusions? Quantitative data on this topic seems a bit nebulous.

Thanks Tom, I'll attempt to install those seals this winter. That shuls solve the problem.

RapRap
1940 ChoppedChevyCoupe

Early Chevrolet V-S's never had cam problems. Some where in the late 60's or 70's they quit using the "spit" holes in the the cam side of the connecting rods. The hole is still in most replacemant rod bearings; it's at the split line. Oil would flow to the cylinder wall and to the cam as the crank rotated. Today when I do a V-8 I will still file a groove in the rod cap so the oil will flow around the rod bolt and out on to the cam.

Another way is to widen the rod side play. In my racing engines I am over .025" which is probably more than needed for a street engine but I would still use a number around .015+" This will flow more oil on the cam. Yes we need the additive, more zinc, but flow will help.

The other culprit is spring pressure If you are not turning a lot of RPM you are probably using to much especially if you follow cam manufacturers specs. Get out an old motors manual and see what a 327 Corvette used for spring pressure and those engines easily reved to 6200. It will suprise you.

In all the years of racing GMC's with a flat tappet cam I have never hurt a lifter or a cam.

Good Luck

jasons and any one else, here is a statement direct from the website you posted, from the author.
What is ZDP?
* Zinc-dialkyl-dithiophosphate
* Abbreviated as ZDP or ZDDP, which ever you prefer
* Forms a polyphosphate tribo film separating the cam lobe from the lifter
* Prevents adhesion of the lobe to the lifter, and break-in scuffing
* Also protects the surfaces from abrasive and corrosive wear

ZDP: the Miracle Drug
* The truly amazing thing is that the ZDP forms this polyphosphate tribo film where it is needed
* A thin film, measured in nanometers, is formed on surfaces as the result of contact pressure and sliding speed
* You only need enough active ZDP to form the film initially and replenish it as it wears away

How Much ZDP is Enough?
* It does not take much ZDP to form these thin films on the wear surfaces
* The ZDP does not “waste itself” forming films on all the surfaces of the crankcase
* ILSAC GF-4/API SM oils contain much more ashless antioxidants, which allow the ZDP to “save itself” for acting as an anti-wear agent instead of an antioxidant

Summary
* The preponderance of dynamometer and vehicle testing indicates that the current level of ZDP in modern passenger car motor oils is more than enough to protect older engines
* If you want to install a high-performance camshaft, invest in a roller-follower cam and lifters



i am saying that the zddp levels are cut way down from past levels. most of us run aftermarket "aggresive cams", we need the zddp to protect the cam and lifters.

modern oil will work fine on a perfectly stock older motor that is already broke in.

try to break a cam in with modern oil and it is a crap shoot. the higher amounts of zddp is surely needed here. tom

That's right but the author also said that large amounts were used in the 70s as an antioxidant, not as a wear additive. The ZDDP would be used up as an antioxidant resulting in less available for wear additive.

Irregardless, I use CI diesel oil. Not worth the chance.

Gentlemen;

Jason's correct, the 'commercial' grade Diesel oils work best for 'flat tappet' cams etc.

Dello 400, SAE 30 is what many use.

Later engines (OHC) & those W/O 'flat tapets' don't need that protection.

Happy trails.

[QUOTE]Originally posted by chopped 40:


"These can be installed without pulling the head if you have the tool to "air up" the cylinder to keep the valve from dropping."

hello,
as an aside to this oil topic,there is another low tech positive way of holding the valves up to replace stem seals -- rope.
the best is soft silver nylon.
with the piston on the up stroke with both valves closed,feed as much of the rope as you can in through the spark plug hole.,leaving a good "tail" outside. (obviously)
then continue to turn the engine as far as it will go before "locking" against the rope all bunched in the cylinder - and hard up against the valves.
then do your job on the seals,turn the engine back to release the rope and haul it on out.
repeat for as many cylinders as you have left.
it works a treat.

regards,Rod

I have used spark plug wire when no rope was handy...SCRAP

So the oil attacked that one lobe? Sounds like a lubrication problem... not defective oil.

Didn't they reduce the ZDP in Rotella @ Dello also? Are those levels still higher?

Chopped, you can also make a tool for the valve stem seal job by taking an old spark plug and brazing a air fitting onto the end of it. I still use the one my dad had from 30 years ago. Cheap and works good

I don't think so, as their used for commercial vehicles.

I'm not sure how to find out (for sure) but; the containers (markings) havn't changed and would have, if the oil had.

We all may need to find an additive; if this "global warming" farse continues.

Another thing here is the spring pressures. These new (import) lifters aren't designed for them & 'hollow out' pretty fast. Then the cam goes, right after.

It's NOT all the oil's fault as mentioned. In the "old days" we just changed out the lifters before that happened.

Happy trails.

they did reduce the levels of ZDDP in both oils, starting in jan of 07. still better than any regular car 10w30 oil though. tom

Greetings . . .

I think that this article has been referenced here before:
Hot Rod: Flat Tappet Cam Tech

And I saw a posting over on the Chevelle board indicating that EOS is back at GM Dealers under a new part number:
EOS Returns: Part # 88862586

regards,
stock49

XXL, our cam lobes went bad due to pour lubrication, not a flow problem. I suspect the cam or lifter was not 100% and the lack of Zinc caused the wear. You cannot expect every lobe of every cam to be perfect, same is true for lifters. With the proper oil, they would of worn in just fine, just have they have done for the last 50 years. But now, with the reduced wear agents, its more important then ever to check and double check everything. Joe

Probably nearing 'dead horse' point, but it seems odd to blame the oil... the one thing that is consistent across ALL lobes (ASSuming it's actually getting there) and not the "not 100%" lobe that failed. Setting aside "engine experience" for a moment, if I were to present a situation where there was a single constant, and only a portion of seemingly identical parts associated with the constant failed, it would be completely illogical to say that the constant was the culprit.

One day I'm sure I'll regret my choice of oils (whatever API SM-level is on sale) and wish I had used something with more magic in it .

I don't think it's bad to beat dead horses. I have a problem with beating live ones,especially if you beat them to death,but once they're dead go for it.! What is old stuff to some is new and valuable to others. I know questions I ask have been asked before. I have spent a lot of time going through old posts but new guys with new information are alwaws showing up,thank God! Maybe we just need to drag all the dead horses into one pile. Then whoever is not in need can just go to the next post. It's all new to someone!

BOP, you are correct on the dead horse thing---there is always someone new coming aboard---like myself when I joined---they need info and it`s good to point them to other posts or give them a good answer-----but Trigger may not like it..52er

XXL asked if any of us ever actually had an engine failure from the choice of oil we used.

I can say that I definitely did. When I was in my teens, in about '58, I rebuilt a '55 235. I was very careful to use the best of parts available at the time and sweated blood over getting the tolerances as close to factory specs as possible. It was bored some, with new oil pump, a mild cam and valve springs from McGurk, headers, larger single barrel carb, etc, etc. When I was about ready to start it, someone recommended that I use 50W racing oil in it. Not knowing any better, that's what I put in the engine. At about 900 miles, the engine spun a rod bearing, turning the crank blue and ruining the rod as well. Some of the other bearings showed damage, too. I'm lucky it didn't throw the rod and bust up my block. I learned that when you use thicker oil, you should build the engine for more clearance. After a re-rebuild, I used used Sinclair detergent 20W. ('55 Chevy recommended 20W summer and 10W winter, but in Florida We used 20W year around)

That engine lasted me for 10 years and was in 3 bodies. It probably had around 100,000 miles on it when I sold the last car with it in it, in '69. Of course, it was MY fault, not the oil's.

So, If I had used the recommended oil with factory slearances, I never would have had to do the rebuild over again!

I will agree, that most people will never have a problem with oil during a break in. Once the new engine is broke in, it really doesn't matter what oil you use.
The main concern these days is the camshaft. Most new cams (Comp Cams for sure) use a much more radical lobe then they did only 10 years ago. They like to slam the vavle open as soon as possible, then drop it shut. You can get a lot of duration with out a lot of over lap doing it this way. The older cams have a much longer ramp on them which produces less stress and wear. Just look at the lift at .050" to .100" and you will see what they are doing. A stock camshaft will be just fine with stock valve springs. Its the radical race cams with high pressure springs that coming apart.

Our engine was a high performance street engine make around 500hp. We used the best products we could and yes, it had a radical cam lobe. Once the hard surface wears, even just a bit, it will eat the cam in just a few miles. The zinc protects and coats just as the lead in fuel did for valve seats.

On the Comp Cams web site, they now recommend Brad Penn Racing oil for all of there cams. Brad Penn is the old green Kendal oil from the 70's. Its still a high Zinc oil, just a Rottella is.

Joe