Reduced Zinc and its Implications

[XS650]

quote:

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Originally posted by Jay:
MolaKule, do you have any opinion on what the new lower limits for phosphorous will mean to motorcyclists that lubricate their transmissions with engine oil? Are the new supplimental organo-metallic esters up to the job of lubricating a gearbox?

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Do the new restrictions apply to xW-40 and thicker oils? The restrictions of SJ and SL didn't.

Look for Allison C4 or Cat TO-2 on your engine oil if you are using it in MC engines. They both require suitable performance for gear trains as well as wet clutches. I think you can also find engine oil that meets GL4, that's probably overkill though and may cause clutch slip problems.

 

[Jay]

Thanks for the comments, MolaKule. Many late-model motorcycles wear catalytic converters now, but I don't think the bike manufacturers have the warrantee liability for them that the auto manufacturers have.

I think most motorcyclists, like myself, forego motorcycle-specific oil because it's so expensive. I make-do with a HDEO, or auto oil.

 

[Peter_M]

An old thread I know but I thought the most appropriate for my question.

ZDDP content is generally talked about in terms of a proportion of the total mass of oil. ie 1400ppm or 0.011% etc.

Because of the mechanism of protection, isn't the most important thing being the total quantity of ZDDP in the sump of the engine that is available to form the protective film under heat and pressure?

To illustrate this question more, assume I have two identical engines except that one has twice the oil capacity to the other. If the large sumped engine contains 10 litres of 700ppm ZDDP oil and the other contains 5 litres of 1400ppm ZDDP oil, if all else is equal, won't the protection afforded by the ZDDP be the same in both engines?

Thanks
Peter


Originally Posted By: MolaKule
There is much interest in reduced phosphorus due to the latest GF-4 sepcs. This was posted in a "zinc" thread but since we have wide interest in this topic, I thought I would also post it here:

Phoshorus is one of the antiwear/antioxidant elements in the Phosphorus/Sulfur/zinc molecule of ZDDP. The sulfur atom of ZDDP is the activation atom for metal bonding, and provides a slight FM effect.

ZDDP's have been used since about 1950 as the primary antioxidant/antiwear agent in engine oils, and are the main source of phosphorus in lubricants. The Sequence IIIC test in the '70's led to the development of oils containing high levels of phosphorus (0.14 mass %). High phosphorus oils can lead to deposits of phosphate on the surface of rare earth element catalysts in the catalytic converters. It has also been discovered that the interaction of metal
detergents with ZDDP and their decomposition products can affect catalyst efficiency. However, the effects depends on the type and relative concentrations of metal and ZDDP in the oil.

In addition, ZDDP's contribute 15-20% of the sulfated ash content of a fresh oil. Reducing the ZDDP should also result in lower piston/ring deposits.

What you're going to see are new ashless antioxidants and AW/EP adds come into play now, such as alkylated diphenylamines (antioxidants), hindered phenols (antioxidants), and new AW adds such as boron esters, concentrated calcium and synthetic AW/EP adds (such as new esters). A newer type of zinc antioxidant/AW additive is ZDTC, or Zinc dialkyldithiocarbamate, which is similar to Moly DTC and Antimony DTC, and only varies as to the metallic element.

 

[HerrStig]

Originally Posted By: MolaKule

quote:

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MolaKule, do you have any opinion on what the new lower limits for phosphorous will mean to motorcyclists that lubricate their transmissions with engine oil? Are the new supplimental organo-metallic esters up to the job of lubricating a gearbox?

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Unless Motorcycles are forced to endure Cats, I don't see any reduction in ZDDP. The ZDDP level should remain at approx. 0.12%.

Just remember, ZDDP is not the cure all; it is simply cheap and has been the incumbent for so many years it has become a defacto standard.

What will happen is that in PCMO's a reduction in ZDDP will occur with a subsequent rise in other additives. The esters are already in production.
There's endless discussion on the BMW air cooled bike sites about this "zinc" problem. Still, lots of people use T6 instead of expensive "bike" oil.

 

[MolaKule]

And as I mentioned in another thread:

Quote:
The other AWs that can displace ZDDP or act as secondary AWs would be the polymer esters, the Ionic Liquids, and the specially synthesized dithiocarbamates.

 

[userfriendly]

The clutch in an automotive application disengages the engine
from the transmission.
The clutch in a motorcycle typically disengages the transmission
from the final drive.
Roll off the throttle and shift a motorcycle quickly
when the slack is present and there is no load on the gears.

CD 50 Eaton Transmission type gear oils are said to reduce gear and
fork traction making shifting easier.

Clutch slippage is not necessarily a bad thing with motorcycles.
It can improve traction.