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-   -   Cylinder wall wetting by diesel fuel (http://www.peachparts.com/shopforum/diesel-discussion/218554-cylinder-wall-wetting-diesel-fuel.html)

Kevin Johnson 04-05-2008 09:41 PM

Quote:

Originally Posted by leathermang (Post 1815315)
If you knew the answers to those questions you might have a harder time holding onto your theory.

No, it's just that this term comes after that exercise. Saves time.

There are quite a number of complete papers online that discuss this -- without paying for the privilege, mind you. I simply took a few hours of my time and read them.

Diesel911 04-05-2008 09:46 PM

I thought that the point of the thread was if you were interested in the threads subject you would want to go to the site and read the article.

That being said I believe even unscientific folks know that all the fuel is not combusted even in a “perfect” engine. The un-burned fuel has to go some where. One of the places some of it ends up is in the crankcase.

Kevin Johnson 04-05-2008 09:49 PM

Quote:

Originally Posted by GRIESL (Post 1815359)
Just wasted ten minutes of my life reading this thread that I'll never get back, and I still don't understand the point of the thread. Seems to me we should all agree that anything in the lubricating oil is bad, no matter what it's own lubricating properties are. Kind of the same idea why we don't pack wheel bearings in Crisco. Possibly the only kind of segregation I support is between fuel and lubricating oil. Just my two cents. Shoot, just wasted another minute of my life writing this. Shoot, another ten seconds. Shoot, another second, ....... Arggghhhh!

Here, just a sec...

http://www.crank-scrapers.com/LubricityStudycopy.jpg

Note carefully that at least one of the items added was lubricating oil. Granted, used Rotella, but new Rotella isn't too much of a stretch. Didn't work so great but it did improve anti-wear characteristics.

Kevin Johnson 04-05-2008 09:53 PM

Quote:

Originally Posted by Diesel911 (Post 1815371)
I thought that the point of the thread was if you were interested in the threads subject you would want to go to the site and read the article.

That being said I believe even unscientific folks know that all the fuel is not combusted even in a “perfect” engine. The un-burned fuel has to go some where. One of the places some of it ends up is in the crankcase.

:thumbsup2:

Craig 04-05-2008 10:03 PM

Kevin, could you explain where you are going with all this?

I think everyone understands that some residual liquid fuel will end up on the cylinder walls and some can find it's way into the crankcase and contaminate the oil.

As brian said above, I think everyone also understands that slight differences in the lubricity of the fuel will have a negligible impact on the overall internal engine friction.

So what is the point of this thread?

Kevin Johnson 04-05-2008 10:20 PM

Quote:

Originally Posted by Craig (Post 1815393)
Kevin, could you explain where you are going with all this?

I think everyone understands that some residual liquid fuel will end up on the cylinder walls and some can find it's way into the crankcase and contaminate the oil.

As brian said above, I think everyone also understands that slight differences in the lubricity of the fuel will have a negligible impact on the overall internal engine friction.

So what is the point of this thread?

Well, one thing that should be clear is that when you are experimenting you need to be careful in your use of terms and about the effect that you are studying.

Brian did not say that lubricity additives will have a negligible effect. If you need me to recite the carefully controlled experiments that do show that at least one additive, LubriSilk, gave significant specific fuel consumption improvements, I can do so.

---- Digression --------
Another very esoteric thing that you can take home from this exercise is how psychological warfare is often conducted through disinformation campaigns. People remember bits and pieces of things that they read or hear and amalgamate them oftentimes into something quite novel -- but incorrect.

I am not saying that malintent is here, by any means, but the effect is clearly observable. Here we have misinformation rather than disinformation.

------- end of digression --------

Craig 04-05-2008 10:28 PM

So what exactly is the point of this thread?

If we are trying to rehash the fuel consumption discussion based on fuel additives, lets shut this down.

leathermang 04-05-2008 11:01 PM

Quote:

Originally Posted by Diesel911 (Post 1815371)
That being said I believe even unscientific folks know that all the fuel is not combusted even in a “perfect” engine. The un-burned fuel has to go some where. One of the places some of it ends up is in the crankcase.

So you think that un-burned fuel is still liquid ?
No chance it was swept out of the bore area with the exhaust gases ?
How do you suppose it gets past two compression rings ?

leathermang 04-05-2008 11:04 PM

Quote:

Originally Posted by Craig (Post 1815415)
So what exactly is the point of this thread?


This thread is designed to keep certain people out of the bars this Saturday night...
and to keep them 'sequestered' from certain other threads...
Don't fall for it !!! Go post on other threads !!!

Dionysius 04-05-2008 11:25 PM

This thread makes a very strong point. The understanding of a topic of any complexity in the real world is usually far beyond our collective capability. As mere mortal humans we are very limited. Our inability to explore multi-dimensional space shows that we can only hope to cope with our imperfect level of understanding.

Here we see a discussion which is very interesting and thought provoking. However those who are more "practically" oriented seem to be quite intolerant of those who can be more "philosophical". Not one of us really knows what is really happening at the molecular and atomic levels. However it is by interacting with each other that we may get some better theory.

In order to expand our collective knowledge let us try to be tolerant of each other. Rudolf Diesel himself would take this stance. As a human species we are failing miserably. The war solution is still called upon as a viable method of resolving conflict. How sad. How miserably stupid.

Long live this thread and I have had a wonderful time learning from it.

Brian Carlton 04-06-2008 10:43 AM

Quote:

Originally Posted by leathermang (Post 1815440)
So you think that un-burned fuel is still liquid ?
No chance it was swept out of the bore area with the exhaust gases ?
How do you suppose it gets past two compression rings ?

Philosophically, I have a hard time with grasping liquid fuel collecting on the walls of the cylinder.

But, it's quite well know that the lubricating oil in most diesels will suffer from some fuel dilution. So, if you take the adamant stance against any fuel bypassing the rings............how do you propose the fuel ends up in the lube oil?

leathermang 04-06-2008 12:35 PM

Perhaps it is not the liquid fuel that gets into the crankcase...but the burned residuals... which, since likes dissolve likes show up as the additive it started out as in the fuel.. at least in the spectrograph analysis.

ForcedInduction 04-06-2008 02:55 PM

I agree. Soot is a "normal" contaminant of Diesel oil, its possible that some can dissolve and appear as raw fuel to chemical and other tests.

Hatterasguy 04-06-2008 03:00 PM

If your getting a lot of fuel in your oil you need to check your injectors because they are not spraying like they should. I'd also check either the left pump or IP, I forget but one can let fuel into the oil.


Cylinder walls are lubricated by the engine oil, thats why they have an oil ring.

2 strokes are lubricated like you suggest.

t walgamuth 04-06-2008 04:22 PM

I have been following this thread and the other one that was locked. I have not posted before because I found myself thinking about things that I had not thought about before...one way and then the other.

Conventional wisdom is that diesels last longer because of the lubricity of the fuel. I don't know if that can be supported scientifically or not.

It follows that there will be less residue on the cylinder walls than on a gasser unless the gasser is a direct injection similar to a diesel.

I know under a non start scenario the gasoline will wash the cylinder walls of lubricant and if an engine is left to sit for a while after this it can rust solid. My brother's '66 230 did this.

Anyway, it all has been thought provoking for me and I was disappointed that the other thread was locked.

Tom W


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