Silicone based oil additives?

[kilou]

Hi,

have you ever heard of silicone based oil additives that are supposed to reduce friction? Is this good or not to use in both engine or transmission? What is your idea about silicone in oil? It seems that silicone molecules are highly attracted by metal and may drastically reduce friction and wear....

See the additive here: http://www.silicoil.co.nz/sillicoil.htm

Thanks

[ June 19, 2004, 06:39 AM: Message edited by: kilou ]

 

[goodvibes]

Liquid silicon is very migratory and sticks to everything, not just metal. This aspect of silicon may not apply here as the compound in question could be no more similar to liquid silicon that it is to sand or glass other than being a liquid. No ideas on this product.

 

[MolaKule]

When you ask a question like this, you need to find out what TYPE of silicon compound (silahydrocarbon) it is. There are approx. 15-20 silicone fluid compounds that qualify as lubricants.

Here is a chart depicting a Falex Test Load to Seizure for various Fluids of approx. the same viscosity:

Pentaerythritol (polyol Ester) - 3,400 psi
TrimethylPropane (polyol Ester) - 3,200 psi
Dibasic Acid Ester - 2,000 psi
PAO - 1,900 PSI
Chlorophenylmethyl Siloxane - 1,100 psi
Petroleum Oil - 750 psi
Methyl alkyl silicone - 725 psi
Methyl phenyl silicone - 75 psi
Diemthyl silicone - 70 psi

In Ryder Gear Test scuff loading, the Methyl phenyl silicones scored above diesters.

The fluoro and methyl siloxanes are good for greases when mixed with diesters and lithium-based grease compounds, especially for lubricating parts which see aluminum-to-aluminum contact.

The advantage of silicone fluids - high flash point and self-extinguishing capabilities, because they extinguish themselves by leaving an ash deposit.

Addendum: Chorophenylmethyl siloxanes have been used for years to lubricate disk drive bearings and tape recording systems motors and bearings.

[ June 19, 2004, 12:24 PM: Message edited by: MolaKule ]

 

[kilou]

Thanks for the info Molakule. Unfortunately (as usual) it is almost impossible to get information from manufacturers about their products so that I do not know what type of silicone is used here.

I have mainly two concerns with these silicones. First as you said, they extinguish and leave an ash deposit. Does it mean that this may clogg the engine quickly (too much deposit is not good)?

Second is about oxygen sensors (lambda sonds). I know this stuff is EXTREMELY sensitive to silicone and this may destroy them very quickly. I assume that if an oil additive is based on silicone, a small amount of silicone may reach the O2 sensor with the exhaust gaz (either if the engine burns oil or via the crankcase ventilation system). Would this destroy the O2 sensor? On the other hand, I've heard about sensor-safe silicones.....................so I'm a bit lost

 

[MolaKule]

Silicon compounds, for the most part, have such high Flash/Fire/Evaporation points that I don't see them evaporating and coating sensors.

 

[kilou]

It has been reported that using silicone base sealing compounds in the engine (for example when sealing the crankcase) may quickly destroy O2 sensors. So I assume that this may be similar with a silicone based additive no? In fact silicone will not evaporate but as you said it will leave ash deposits and these deposits may go on the sensor no?

I've seeking some informations on the web about O2 sensors and there are everywhere warnings concerning silicone but they never speak about engine oil additive though...

 

[MolaKule]

See this thread:

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic&f=4&t=000334#000000

 

[kilou]

Is silicone the same as ceramic or is there other types of silicone-based additives? Ceramic is a solid lubricant no?