From: cbm@athena.mit.edu (Charles Bruce Musgrave)
Newsgroups: rec.autos.tech
Subject: Re: SLICK-50
Date: 26 Jun 1995 15:53:49 GMT
Organization: Massachusetts Institute of Technology
Lines: 72

In article <3s9dqo$l6j@charm.magnus.acs.ohio-state.edu>,
dheister@magnus.acs.ohio-state.edu (David J Heisterberg) writes:

|> In article <3s9bjk$htc@news.ysu.edu>,
|> George Kalemanis <ag256@yfn.ysu.edu> wrote:
|> >Rod Bearings......55 %
|> >Main Bearings.....34 %
|> >Piston rings......43 %
|> >Rocker arms.......22 %
|> >Average of all parts 39 % LESS WEAR COMFIRMED BY SRI (Southwest Research 
|> >Insitute, they know a little more then some ASE mach.)
|> 
|> Ah, the bearing mass loss test.  As it happens I just picked up
|> "Engine oils and automotive lubrication" edited by Wilfried J. Bartz.
|> It was published in '93, very up-to-date.  The very first paper was
|> on the development of a capacitive device for measuring minimum oil
|> film thickness in connecting rod big-end bearings during engine
|> operation.  It was pretty tricky.  SwRI did the actual testing in
|> this case, too.  Now the reason for the direct MOFT measurement is
|> that bearing mass loss tests have terrible reproducibility.  They

especially if you have a coating which can adhere to the non-wear
surfaces...

|> are best left as the ultimate arbiter in determining total bearing
|> failure.
|> 
|> I went through a dozen or so books and conference proceedings looking
|> for use of PTFE in engine applications.  It's great when used properly,
|> in bronze-lead-PTFE sintered bearing surfaces, but has absolutely no
|> use as a solid dispersant.

Good work! You found papers on the subject from the tribological community.
Yes, it works very well as an ALLOYED film...with copper or Ti
for example, and usually sputtered on to the surfaces. Funny how 
a lot of the bozos who believe slick 50 have little materials knowledge
yet they make all sorts of claims. The Tribological Series by Elsevier
is quite good by the way and has enough papers in it to get a good 
understanding of the subject. Of course, George hasn't read those papers
so they don't count.

|> Oils already contain extreme pressure additives (EPAs) of various
|> types that are designed to decompose or undergo some physical
|> change that allows them to temporarily adhere to metal surfaces
|> under conditions of extreme pressure, heat, or electric field.
|> [I didn't know this, but electric fields of 4000V/cm are not
|> uncommon at incipient metal to metal contact in journal-type
|> bearings.]  These EPAs are typically organo zinc compounds and
|> borates.  Some of them form essentially monomolecular layers on
|> the metal surface.

Yes. But don't spend too much time refuting the slick-50 types...
I posted a lot of the data and references last year and of course, the slick 50
crowd didn't spend a second trying to read up on the subject, even after
I looked up and typed in the references.


|> The level of engineering and model complexity in CarCraft type
|> explanations is many, many decades behind that of modern automotive
|> engineering.  I wish some of these jokers would actually read
|> current papers on these subjects.

WHo needs to read the literature. Some scientifick studie was did
and they says it works. I read it so it must be true.

|> -- 
|> David J. Heisterberg                        Ich grolle nichte, und
|> Dept. of Chemistry OSU /                  wenn das Herz auch bricht.
|> The Ohio Supercomputer Center               -- Heine

have a good one,
Charles