[glen242]

What, exactly, is ZDDP? I see posts regarding ZDDP, but what exactly does this ZDDP mean? How is ZDDP calculated? I never see any data as to how it relates to Zinc/Phosphorus present in oil.

My present oil, Valvoline VR1 has 0.14 Zinc and 0.13 Phosphorus. How does this correlate to ZDDP? I have never seen any ZDDP numbers that relate to Zinc and Phosphorus numbers i.e. this amount of ZDDP = this amount of Zinc and Phosphorus .

It seems that, as I mentioned in a prior post, that ZDDP is a lazy man's way of equating Zinc and Phosphorus, sort of a short hand. But again, I have never seen the values related.

[327NUT]

google it for a lot of reading.

[sbchevfreak]

It seems that, as I mentioned in a prior post, that ZDDP is a lazy man's way of equating Zinc and Phosphorus, sort of a short hand. But again, I have never seen the values related.

ZDDP (Zinc dialkyldithiophosphates) is a compound that is use to add the levels of both Zinc and Phosphourus that flat tappet cams require. I can't remember who invented the combination, but it has been used for decades as a direct additive to increase the EP characteristics of engine oils. As environmental regs and the auto manufacturers have changed, these levels have become signficantly lower, to the point of being insufficent for flat tappet cam engines.

You won't see an actual ZDDP value listed for probably any oil, as it is just the additive used to bring up the Zinc and Phosphourus levels in the oil. Thus, the those levels will be posted, but not the ZDDP, as it is the additve that contains the required elements.

[oldbogie]

Originally Posted by glen242

What, exactly, is ZDDP? I see posts regarding ZDDP, but what exactly does this ZDDP mean? How is ZDDP calculated? I never see any data as to how it relates to Zinc/Phosphorus present in oil.

My present oil, Valvoline VR1 has 0.14 Zinc and 0.13 Phosphorus. How does this correlate to ZDDP? I have never seen any ZDDP numbers that relate to Zinc and Phosphorus numbers i.e. this amount of ZDDP = this amount of Zinc and Phosphorus .

It seems that, as I mentioned in a prior post, that ZDDP is a lazy man's way of equating Zinc and Phosphorus, sort of a short hand. But again, I have never seen the values related.

It used to be found at levels of about 1000-1400 parts per million, today it's about 10% of that or less.

Bogie

[glen242]

Thanks sbchevfreak and oldbogie.

My question is still unanswered.

If Z and P levels, in oil, can be obtained, what the HELL and how in the HELL does ZDDP relate? Is the ZDDP notation just good for the 'snake oil' salesmen to hype their product?

We all have a good idea of how much Z and P we need to have in our oil for flat tappet cams. Some posts here and on Google (327NUT) seem to just say that ZDDP is an additive as it is just the additive used to bring up the Zinc and Phosphourus levels in the oil.

BTW, Wikipee (or what ever) said ZDDP was formulated by Castrol.

I have no problem with that except when people refer to ZDDP levels as equal to the Z and P in the oil.

Always willing to learn. Please correct me, with docs, where I am wrong.

[sbchevfreak]

Originally Posted by sbchevfreak

You won't see an actual ZDDP value listed for probably any oil, as it is just the additive used to bring up the Zinc and Phosphourus levels in the oil. Thus, the those levels will be posted, but not the ZDDP, as it is the additve that contains the required elements.

This is an answer to you question, is it not?

Originally Posted by glen242

If Z and P levels, in oil, can be obtained, what the HELL and how in the HELL does ZDDP relate? Is the ZDDP notation just good for the 'snake oil' salesmen to hype their product?

ZDDP is a blend of chemicals that carries the zinc and phosphourus needed by flat tappet cams. It is one method of adding the missing zinc and phosphourus to today's oils, making them flat tappet friendly. In the past, these elements were added during the processing of base stock. As the levels dropped, and oils became insufficient at lubricating flat tappet camshafts, a supplemental additive had to be developed. As we all knw, adding things to oil, or fuel, after the processing stage is usually ineffective. ZDDP was developed to replace a missing additive package in engine oil, and to be assimilated as though this package had been added during the refining process. The formulation of the zinc dialkyldithiophosphate allows the two elements to be "dissolved" and assimilated into the base engine oil. Once in the oil, the zinc and phosphourus can be carried by the oil and add the extreme pressure lubricating properties that flat tappets need to keep from destroying a cam lobe.

ZDDP, once it is in the oil, can be measured by determining the zinc and phosphourus levels contained in the oil. You can't analyze the oil and find out there is "X" ppm of ZDDP, but, you can analyze 2 oil samples from the same sample material, one before ZDDP added, and one after. The second oil sample will show elevated levels of zinc and phosphourus, with slightly more ash content. It has been a while, but I had to do this exact test as a lab assignment in my oil chemistry program at SAIT.



HTH.

[OLNOLAN]

Hey Glen, This may give you some leads to your question. Read this thread;
Shell Rotella T

MSDS on the products are don't get real specific on the levels of each portion of the additives, just the total as a percentage or PPM contained. Some are not ZDDP's, appear to be ZADP's. I suppose it's about trade secrets. Here is an example of an oil MSDS containing additive levels;
http://aomegainc.com/images/msds/delo400_msds.pdf

Nolan

[oldbogie]

Originally Posted by glen242

Thanks sbchevfreak and oldbogie.

My question is still unanswered.

If Z and P levels, in oil, can be obtained, what the HELL and how in the HELL does ZDDP relate? Is the ZDDP notation just good for the 'snake oil' salesmen to hype their product?

We all have a good idea of how much Z and P we need to have in our oil for flat tappet cams. Some posts here and on Google (327NUT) seem to just say that ZDDP is an additive as it is just the additive used to bring up the Zinc and Phosphourus levels in the oil.

BTW, Wikipee (or what ever) said ZDDP was formulated by Castrol.

I have no problem with that except when people refer to ZDDP levels as equal to the Z and P in the oil.

Always willing to learn. Please correct me, with docs, where I am wrong.

Not quite sure what your searching for in understanding this but I'll take a shot.

ZDDP is just short hand for the chemical additive Zinc-dialkyldithiophosphate.
The chemistry basically is zinc oxide reacted with phosphorus pentasulfide which is a form of phosphoric acid and most any alcohol to make ZDDP which has the chemical formula (Zn((S2P(OEt)2)2). The Zn and the P being the zinc and phosphorous. This stuff is a solid or "dry" lubricant along the lines of molybdenum or graphite. However, unlike moly or graphite compounds (another lengthy subject) ZDDP dissolves in oil, mineral or synthetic. Moly and graphite chemistry mixes with oils but does not dissolve, both eventually form coagulation's that become large enough for the filter to capture which does not happen with ZDDP.

These dry lubricants were added to engine oil to provide an Extreme Pressure lubricant for the camshaft lobes and tappets. Within the journal type bearings of the crankshaft, rods, and the cam the rotation of these type bearings picks up the oil being pumped to them and forms a high pressure wave that travels around the bearing and journal separating them on what is called a hydrodynamic wedge. The wedge is constantly renewed as oil escapes the clearance taking heat and debris with it and is replaced by fresh filtered oil. This type bearing lubrication doesn not benefit from dry additives unless you run the engine out of oil, then for a while they will cover your infraction.

The cam lobe and flat tappet interface is a different issue, there is a scrubbing action that wipes the oil off the flanks and crown of the lobe due to the vibratory and alternating pressures from the valve spring combined with the small contact area. A dry lube is useful here because they are resistant to these actions because they like to bind with metal parts to form a lubrication layer of a couple microns in thickness. This has been known for many decades when long and hard searches were done to find a dry lube that could be added to oil to protect the cam and lifters. But the chemistry of moly and graphite and later in the 1970s Teflon was always a diminishing protection because these chemicals like themselves more than oil or metals and so joined up to where they formed clumps big enough for the filter to capture so by the time an oil change was due the filter was plugged (hence filter bypass valves) and the cam and lifter interface was naked metal against metal. You can run 'em like this but it really restricts the cam design to very mild lift rates and low spring pressures. The muscle car era owes its existence to ZDDP as it was discovered that this stuff made an excellent dry lubricant with all the needed properties of metallic adhesion but since it dissolved into oil like sugar or salt does into water it wouldn't form precipitates that the filter would capture so the stuff maintained protection for the duration of oil changes and beyond, hence extended oil changes.

The down side, like all solutions when you evaporate the solution (liquid) the dissolved chemical (solute) will eventually precipitate. This is what happens with oil pulled into the combustion chamber and sent out the exhaust to a catalytic converter. At the converter any oil that lands on the catalyst bed is burnt to water and CO2 but any solid chemicals whether dissolved or mixed with the oil are left behind coating the rare metals that catalyze the reactions of pollutants to less harmful compounds stopping their action. So starting in the 1980's the EPA began to legislate a reduction in these chemical dry lubes in oils as they did with the lead, sulfur, and bromine compounds in fuels that also kill the catalytic converter by the same process as previously described for ZDDP.

The factories responded to the lowering of the ZDDP fractions in oil by going to roller cams in cars. They mostly kept flat tappet cams in trucks because the lift and durations were so mild as not to cause a wear problem at least through the warranty period where they were on the hook for the cost of any fixes.

The problem with the aftermarket hot rod industry is that they just haven't really coped with this change in the 25 ensuing years, they're still out there selling high lift/fast lift, powerful valve springs against flat tappet cams because they are cheap to make and that draws many customers who are unsuspecting as to what they're getting themselves into.

Zinc and phosphorus are not free floaters out there in the oil they are bound in the molecular chemistry of ZDDP which is really a type of soap not a lot unlike the soaps used to make greases.

Bogie

[sbchevfreak]

Thanks, Bogie, for the in-depth explanation. There should be no question now abot ZDDP in oils, very detailed post.

[techinspector1]

Thanks Bogie, as always....over the top

[Jon]

oldbogie -- any interest in archiving that post in the wiki? I can copy-paste it in there for you, but if you register a wiki username and do it yourself, it would be listed under your username.

[oldbogie]

Originally Posted by Jon

oldbogie -- any interest in archiving that post in the wiki? I can copy-paste it in there for you, but if you register a wiki username and do it yourself, it would be listed under your username.

Yeah, but give me a little time I'm just relaxing my brain for a few minutes right now from a really messy problem that I've got to get back into for a few hours.

Bogie

[glen242]

Bogie, great explanation.

Thank you.