can Oil be TOO slippery ?

[Truckedup]

I once knew a guy who put some magic oil additive (PTFE based?) in a Peugeot 504 manual gearbox and it was slippery enough that the synchros refused to work.

Some GL5 gear oils can be too slippery and can cause synchro problems in some older gear boxes with bronze blocker rings.
How slippery was Castor bean oil when it was the choice for racing?

[raynorshine]

"Slippery" probably isn't the best word.
"Adhesiveness " is probably a better word.
If an oil doesn't have enough adhesive properties, that can be an issue. That's the issue with some synthetic oils on flat tappet cams.
If the oil doesn't leave a sufficient layer of oil on the lobes and lifter faces, what's there is easily scraped off, and there's no protective barrier between the 2 metal surfaces rubbing against each other.

-"Adhesiveness"- isn't that a different oil property? wouldn't that be the technical term for "sticky"(redneck)

[autogear]

I once knew a guy who put some magic oil additive (PTFE based?) in a Peugeot 504 manual gearbox and it was slippery enough that the synchros refused to work.

Some GL5 gear oils can be too slippery and can cause synchro problems in some older gear boxes with bronze blocker rings.
How slippery was Castor bean oil when it was the choice for racing?

I've somewhat recently had to avoid even certain "GL4" oils because of synchronizer (blocker) ring problems. Typical symptom was extremely poor shifting about 4000rpm and impossible to shift up or down past about 4500rpm. Draining the oil showed an abundance of bronze metallics in the oil, even with brand new, expensive FORGED blockers. People using the cheap 4 dollar cast rings, sometimes see the same issues.

[Sweet P]

Bullet Cam told me to never run moly in a roller cam engine, it works so well that the lifters rollers skid across the cam lobes vs rolling.

[Truckedup]

Bullet Cam told me to never run moly in a roller cam engine, it works so well that the lifters rollers skid across the cam lobes vs rolling.

Dont' all the latest car oils have some type of moly.?

[Rick!]

I have wondered if roller bearing engines like motocross bikes use end up skating on the slippery oils, some have seprate engine and trans oil.

I ran dirt bikes for several years and always avoided oils with moly. Usually the thick service manual had something to say about it. Honda was pretty particular about mentioning to avoid moly oils in their dirtcycles. I never ran cranks longer than 80 hours as I was more concerned about the rod than the crank bearings.

[David Redszus]

Brief answer: yes.

A somewhat recent case, but unrelated to the second question (with respect to ring sealing) was when automotive oils became unsuitable for use in motorcycle wet clutches. I had to replace the clutch pack in my Benelli Sei because of this.

https://en.wikipedia.org/wiki/Friction_modifier

The term "slippery" refers to a reduction in the coefficient of friction; a result of oil viscosity and oil film thickness.

Viscosity changes with temperature and oil film thickness varies with clearance. For engine oils, an oil
cannot be too "slippery" unless that oil has other reduced properties.

For a wet clutch (or wet brake) system, things change. If the oil viscosity is too high, the surfaces will slip. If the
viscosity is too low, the surfaces will grab. Taken together we have a condition called stick-slip.

Wet clutch oils have an additives that controls the slippage ramp; it allows sufficient slippage to avoid stick but allows enough grab to transfer power. Synchro rings are affected similarly.

While an engine can use either oil, wet clutches cannot. The additive is consumed with use and must be
replaced.

Standing start karts and bikes gained a great advantage off the line, but needed a clutch oil change every four race weekends.

[Jeff Lee]

Back around 1977 and in HS, bought a ’69 Mach1 with 351W 4-bbl (one year only option at 290 HP), 4-speed. Used very little oil. Then somebody came out with a graphic impregnated oil and it was all over the advertising. So I bought it. Engine immediately idled better, ran better, faster. I was ecstatic.
Very soon, it started consuming oil like crazy (no leaks). I changed back to Pennzoil and the consumption issue went away. Maybe too “slippery”?

[raynorshine]

Back around 1977 and in HS, bought a ’69 Mach1 with 351W 4-bbl (one year only option at 290 HP), 4-speed. Used very little oil. Then somebody came out with a graphic impregnated oil and it was all over the advertising. So I bought it. Engine immediately idled better, ran better, faster. I was ecstatic.
Very soon, it started consuming oil like crazy (no leaks). I changed back to Pennzoil and the consumption issue went away. Maybe too “slippery”?

ya maybe too "slippery"......

-would you'alls prefer another term....how bouts...."sliptivity"

[Kevin Johnson]

Back around 1977 and in HS, bought a ’69 Mach1 with 351W 4-bbl (one year only option at 290 HP), 4-speed. Used very little oil. Then somebody came out with a graphic impregnated oil and it was all over the advertising. So I bought it. Engine immediately idled better, ran better, faster. I was ecstatic.
Very soon, it started consuming oil like crazy (no leaks). I changed back to Pennzoil and the consumption issue went away. Maybe too “slippery”?

There are many threads about Arco Graphite (I remember it too). Within the threads are numerous anecdotal experiences that are often denied because they are not consistently reproducible in a lab. For example: https://www.bobistheoilguy.com/forums/u ... /1878052/5

For your consideration:

Machining operations that can induce magnetism: http://www.bussi-demagnetizers.com/en/e ... -machining

Creation of magnetic graphite by physical processing:


Hypothesis: The particular conditions in your engine/engine-components created a weak magnetic field -- perhaps in the rings as a result of wear in the bores or they were improperly degaussed somehow during their manufacture. It is possible (demonstrated empirically in the video) for graphite to exhibit magnetism through physical work being performed on it. The graphite in the oil temporarily collected in ways on the rings that allowed a thicker oil film to pass through to the combustion chamber and be consumed.

Closing reference:
https://en.wikipedia.org/wiki/Journal_o ... le_Results

My Father told me of a chemistry student at UofM that had a mental breakdown because his lab experiments were not proceeding according to theory.

[digger]

In an engine I don’t think there is too slippery once run in

[Truckedup]

The term "slippery" refers to a reduction in the coefficient of friction; a result of oil viscosity and oil film thickness.

Viscosity changes with temperature and oil film thickness varies with clearance. For engine oils, an oil
cannot be too "slippery" unless that oil has other reduced properties.

For a wet clutch (or wet brake) system, things change. If the oil viscosity is too high, the surfaces will slip. If the
viscosity is too low, the surfaces will grab. Taken together we have a condition called stick-slip.

Wet clutch oils have an additives that controls the slippage ramp; it allows sufficient slippage to avoid stick but allows enough grab to transfer power. Synchro rings are affected similarly.

While an engine can use either oil, wet clutches cannot. The additive is consumed with use and must be
replaced.

Standing start karts and bikes gained a great advantage off the line, but needed a clutch oil change every four race weekends.

Bike clutch issues started about 20 or so yeas ago when motor oil first got the API Starburst label.Yes, about the same time as flat tappet cams failing .Before than time there were no clutch sticking or slipping problems when using any motor oil .The Japanese bike manufacturers appealed to the API and got a JASO rating on oil suitable for wet clutches.These oils generally, but not always, carry a SG or SH rating rather than the current SL or SN. And generally but not always, say JASO on the oil container
What is not in bike oils is Moly type friction modifiers as listed on oil manufacturer information.If anything is added, I have no idea of what...
From my own experience I have found that oil with high ZDDP levels seem to cancel out the non wanted friction modifiers...Some Diesel oils lhave a JASO rating for whatever reasons, Rotella T4 is popular for use in bikes.
Many bikers have noticed from experience ,that bikes having a common oil supply for engine and transmission/clutch, the shifting feel can change over time with some brands of oil. The oil ,in my hillbilly language, gets used up from shear caused by the tranny gears. Or by products of engine operatin are affecting the oil...
This is a lab anaylsis I had done of a non used bike oil having a solid repuation with racers.....The lab obviously does not test for every addtive...but you see other than ZDDP and calcium( I believe is a detergent?) there not much in it...

[raynorshine]

In an engine I don’t think there is too slippery once run in

-i think i read many years ago, 90% of the friction in an internal combustion engine, is at..the rings...

-does this sound correct? or?

[David Redszus]

There are many threads about Arco Graphite (I remember it too). Within the threads are numerous anecdotal experiences that are often denied because they are not consistently reproducible in a lab.

No solid particle, whether graphite or Teflon, has a lower
Coefficient of Friction than does a liquid film.

My Father told me of a chemistry student at UofM that had a mental breakdown because his lab experiments were not proceeding according to theory.

As a teen age student at university, I nearly flunked out of my physics lab because the lab results did not match the theoretical
predictions. So, I would repeat the experiment several times, each with a different result. Then the clock ran out.

Dazed and dejected, I asked my Prof what did I do wrong. He said: "The results were not supposed to match theory; they were intended
to show the inaccuracy of measurement procedures. You were suppose to just record the results and not attempt to analyse them."

[MadBill]

In an engine I don’t think there is too slippery once run in

-i think i read many years ago, 90% of the friction in an internal combustion engine, is at..the rings...

-does this sound correct? or?

No, it's typically more like 20-25%.