What Moly is in use?

[GMorg]

I noticed from a link provided by another BITOGer (MGBV8) that Penrite cleary holds the position that MoDisulfide does NOT belong in motor oil. The "moly Basics" section here describes only MoDisulfide. On the other hand, MoDTC seems to be in current use. I have two basic questions.

1) What Molybdenum compounds are currently being used?

2) When the term "soluable moly" is used, to what compound is the reference being made?

 

[bruce381]

Moly di thio carbamate
"Molyvan L"
see Vanderbilt chemical.

Oil Soluble moly
see Vanderbilt chemical products called "Molyvan"

Old Moly disulfide is a black/gray powder like talc which will settle out and Clog stuff up very good in grease and gear oils.
bruce

 

[GMorg]

Thanks bruce381,

That's what I thought. So, does it follow that the BITOG "Moly Basics" section is out of date? Has the "stack of cards" analogy for graphite and Moly disulfide lost it's utility?

 

[MikeyG]

quote:

---

Old Moly disulfide is a black/gray powder like talc which will settle out and Clog stuff up very good in grease and gear oils.

---

I disagree with the "clog stuff up". I have been using MolySlip (MoS2) in a turbocharged 98 Acura EL for a minimum of 100 000kms. Currently the car has 251 000 kms. As per MolySlip website the average size of the particle is .5 microns, significantly smaller than filter media passageways. So, no clogging. Just my $0.02.

 

[GMorg]

MikeyG,

I am still on the fence when it comes to solids in oil. You are not alone, many people have had good luck with some of these products (or aleast the lack of bad luck).

My take on the "clog stuff up" argument is that it needs to be considered in more than one way. Beyond particle size issues that allow it to pass the filter, one must consider wether it will settle in low-use engines and wether it will aggregate with soot, sludge, water droplets, ect.

I am still unclear as to why/when a product is considered benificial in a gearbox yet detrimental in an engine.

 

[GMorg]

For those BITOGers that like to see high moly values in VOA/UOA, do you hope that you are measuring Moly Disulfide or MoDTC? And if you do hope for MoDTC, why Moly. Why not any of the other thiocarbomyls or thiophosphates?

 

[MikeyG]

There is no question that it will settle. When you empty a can of MolySlip there is always a film of Mos2 along the sides and bottom of the can. By adding a small amt. of oil and gently swishing it around the remainder of the MoS2 will mix with the oil. Compare that to the circulation of oil in your oil pan. When I had my oil pan tapped for the oil return line for the turbo there was a layer of MoS2. I am not sure how much. Whenever I change the oil it has always come out blackened due to the charcoal colour of Moly. So, it does settle to a degree, and it stays in solution. As for bonding with other particulate/water I have no idea. It had never occurred to me as being an issue. If the particle (MoS2 + soot etc) gets too large I assume it will be caught in the filter. I am not clear on the development of sludge. I think that is mostly determined by oil being used, the type of engine, and driver habits. My car has not shown any signs of sludge. As for water???

 

[Blue99]

Whenever the subject of moly and its' function as a motor oil additive comes up, I think it is generally understood that it is MODTC, and the other soluable forms, being discussed.

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=4;t=000353

Molakule has always clearly indicated that the best use of Molybdenum Disulfide powder is for greases.

Next time you are browsing the oil aisle, take a look at the Quaker State 4X4 Synthetic Blend in the clear plastic bottle.

This formulation has over 200+ ppm of moly & obviously it's a soluable form, as no additive fallout is visible in the bottom of the bottle.

 

[MolaKule]

http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=56;t=000002

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=56;t=000026

Q1) What Molybdenum compounds are currently being used?

Molybdenum Disulfide and Moly Dialkyldithiocarbamate.

Q2) When the term "soluable moly" is used, to what compound is the reference being made?

Moly Dialkyldithiocarbamate (MoDTC) and Moly dithiophosphates (MoDTP).

MoDTP is used in hydraulic fluids and MoDTC is used in motor oils.

Moly disulfide compounds as suspended powders are used in gear lubes and greases.

 

[GMorg]

Thanks all...

I found MolaKule's second thread interesting from the GMO point of view. If the lube guys could settle on the chemistry that they want from GMOs, it would be relatively straightforward to produce the organisms...

 

[MolaKule]

quote:

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Has the "stack of cards" analogy for graphite and Moly disulfide lost it's utility?

---

Not for moly disulfide.

For soluble moly, yes, and a lot of explanation on BITOG has gone into delineating the two.

See also:

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=21;t=000032

 

[GMorg]

When we see/hear of high moly due to assembly lube, can we assume (with high probabililty of being correct) that the moly is from one source or another. My recollection is that the Crane grease that used to come with a new cam was very high in MoDisulfide. Are MoDiSulfide greases the source of assembly moly?

 

[MolaKule]

Yes, if it is assembly grease, it is most likely MoS2.

Our liquid assembly lube contains soluble moly with four EP adds and three AW adds in a synthetic base.

 

[GMorg]

Thanks to all.