From: cbm@athena.mit.edu (Charles Bruce Musgrave)
Newsgroups: alt.autos.antique,alt.autos.camaro.firebird,alt.autos.macho-trucks,
	alt.autos.rod-n-custom,austin.autos,rec.autos.4x4,rec.autos.antique,
	rec.autos.driving,rec.autos.marketplace,rec.autos.misc,rec.autos.rod-n-custom,
	rec.autos.tech,rec.autos.maker
Subject: Re: Slick 50
Date: 17 Apr 1996 22:54:30 GMT

In article <4kngds$asi@news.express.co.nz>, bruce@faxmail.co.nz (Bruce
Simpson) writes:

|> >now, to test the prelube, take a piece of
|> >sheet metal and rub it with a penny for 5-10 minutes non-stop. you'll see
|> >a line on the metal from the wear (and the burn on your hand from the now-
|> >hot penny!) now, put some oil on the other side of the metal. rub for
|> >fivew minutes, constantly adding oil. there will be less wear. I guarantee
|> >it. and less finger burn, too.  Prelube oils the engine up before it
|> >starts. after you shut off your engine, all the oil drains down into the
|> >oil pan. when you first start your engine, the oil is still down in the
|> >pan, not on the engine parts. prelube puts the oil on the engine parts
|> >before it starts, so there is no dry metal-on- dry metal, which is when
|> >most wear occurs.
|> 
|> I can't agree with all your assertions here.  For a start, not *all* of the
|> oil drains back down into the pan.  A thin film remains on all the working
|> parts (including the bearings, camshaft, etc).  The film-strength of this
|> remaining oil is more than adequate to protect the moving parts at startup
|> until full oil-pressure is established.  There are many roller/ball

I think this is overstating the ability of cold, thin lubricant films.
If you your assertion were true, then just about every cold start wear 
study ever conducted would be wrong.  

|> bearings in a car which have no presurised oil feed but they last just fine
|> (wheel-bearings, alternator, water-pump, etc)  Bushes (big/little end) need
|> more lubrication than roller/ball bearings but even they aren't in any
|> danger at startup time.  Remember, at startup, the engine is subject to no
|> load and running at very low revs, the bearings simply aren't being

The engine is subject to load at startup (have you ever tried to turn
an engine by hand?  Compression provides some load).  Furthermore, rings
automatically place a sliding load on the cylinder walls...including
at start up.  

|> stressed anywhere near their designed ratings.  Just look at the number of

And the oil viscosity and pressure are also no where near their designed
values.

|> mechanical devices that have *no* presurised oil system yet don't wear out
|> particularly quickly:

What do you mean by quickly?  If wear is as little of a problem as you 
suggest, then I wonder why GM pays me as a consultant to find ways to 
reduce engine/transmission wear?

|> 
|> 	cycle and motorcycle chains,
|> 	bushed electric motors
|> 	etc, etc.
|> 
|> Perhaps better value than a prelube is the use of synthetic oil.
|> Comprehensive tests undertaken by synth oil manufacturers show that even
|> after high mileages (without prelubes), engines running synthetic oils have
|> virtually no perceptable wear on bearing surfaces.  Nuff said?

You're asking Nuff said after bringing up studies on synthetic oil being
superior conducted by synthetic oil makers?  That's smart.



Charles

From: cbm@athena.mit.edu (Charles Bruce Musgrave)
Newsgroups: alt.autos.antique,alt.autos.camaro.firebird,alt.autos.macho-trucks,
	alt.autos.rod-n-custom,austin.autos,rec.autos.4x4,rec.autos.antique,
	rec.autos.driving,rec.autos.marketplace,rec.autos.misc,rec.autos.rod-n-custom,
	rec.autos.tech,rec.autos.maker
Subject: Re: Slick 50
Date: 25 Apr 1996 16:49:41 GMT

In article <4lni0j$scq@news.express.co.nz>, bruce@faxmail.co.nz (Bruce
Simpson) writes:

|> cbm@athena.mit.edu (Charles Bruce Musgrave) wrote:
|> 
|> >In article <4lcsku$m6q@news.express.co.nz>, bruce@faxmail.co.nz
|> >(Bruce Simpson) writes:
|> 
|> >|> If the level of wear concerned is so small as to be barely perceptable
|> >|> over the life of an engine then 50% of bugger-all is purely accademic
|> >|> isn't it?
|> 
|> >It is only barely perceptable in the best case.
|> 
|> You mean when regular maintenance is performed and a good quality
|> (synthetic?) engine oil is used?  If that's the case are you advocating the
|> use of a prelube *instead* of such a maintenance regime?

No.  Why would you make such a great leap of logic?  


|> >a) You should never top off the oil.
|> 
|> Why do all of the oil companies make those little bottles of oil then?
|> Surely if topping up the oil was a bad thing, they'd refuse to sell the
|> little bottles and make us buy a whole gallon and perform a complete oil
|> change.

You fill to the fill line, not to the top of your crack case.  You do not 
fill your crackcase to the top unless you want to possibly blow your seals. 
 

|> >BTW-my parents 1985 Honda had its engine replaced at 200kkm, although
|> >it was properly maintained...
|> 
|> Bet they didn't use synthetic oil :-)

Bet they did...just like I do.


|> >|> What would Slick-50 or a prelube done for this car?
|> 
|> >Slick-50?  Who knows exactly.  Preluber?  Reduced its wear.
|> 
|> But by how much?

A lot.  My mother takes 3 or 4 short trips a day starting from
a cold start.  That's two thousand miles of wear in 20 miles
of driving. 


|> >|> But a pre-lube isn't going to lube the bore is it? 
|> 
|> >And why not?
|> 
|> Are their oil galleries which lead directly to the bore?  I've never
|> actually checked this - how does the oil get from the gudgeon-pin to the
|> piston skirt?  I thought most of the bore-lube was from the spray of oil
|> which occured when oil was flung off the big and little-end bearings of the
|> con-rod.  This doesn't happen until the engine is actually moving does it?

Depends on the engine design.  Some are not the piped passageways the way
you'd usually think of an oil supply route, but are thin spaces between
sliding surfaces.  Since the oil is pressurized it can flow down the gradient
to supply these surfaces if the hydrodynamics work.


|> >|> an idling engine are *much* lower than those on one driving a load
|> >|> at revs.
|> 
|> >Then why do we measure spikes in the metal content of oil directly after
|> >startup, which decrease over time?
|> 
|> Spikes of what magnitude?  I think we need to maintain quantitive

A cold start can cause between 200-1000 miles or wear (we normalized
by the wear rate with fresh oil at highway speeds).  Some of this
is due to build up of unburnt hydrocarbons which aggregate while the
oil is cold and are not boiled off.  Some is due to acidic attack of
the engine metal due to oxidation of the oil and hydrobromic acids 
which aren't boiled off until the engine is warmed above 140F.  
But if you subtract off the metal desolution rates from the non-load
mechanisms you still get 100-500 miles of wear from insufficient lube
at start up.

|> measurements in mind.  A spike might be as little as an increase of 0.0001%
|> if the background level is normally very stable.  What we need to know is -
|> what is the actual significance of that spike in respect of engine-life?

Of course.  


|> >Your talking about the hydrostatic/dynamic effects of oil in your engine,
|> >which although important, doesn't say anything about whether a very thin,
|> >cold and non-pressurized film can protect a bearing under low load.
|> 
|> Hell ... why have oil-cans been around for so long?  What about the old
|> traction-engines and stationary engines with huge bearing loads and no
|> pressurised oil feeds - what about 2-stroke engines with only a "thin
|> non-pressurised film" on their bearing surfaces?  What about those small
|> industrial four-stroke engines (eg: B&S) which only rely on
|> splash-lubrication and therefore have bearings that rely simply on
|> passive-film bearing lubrication?

The thickness of the film in all these applications is much thicker than
at the engine surfaces in an engine that has been sitting for a long time.
Due to flow delays, hydrodynamics of the edge of the lubricant and surface 
tension effects you get an effective pressurized lubricant.  


|> According to your assertions, these engines would fall appart in a matter
|> of just a few hours - worn completely out due to the lack of lubrication.

No.  Maybe according to your non-expert interpretation of my description of a 
completely different system.

|> The reality of course is that many of these engines put in thousands of
|> hours of reliable operation with minimal attention.  Are these anomolous
|> results to be explained by "magic"?  :-)

No.  Read up in the tribology literature.  It is quite well explained ;)


|> >Tell me your estimate of the ability of the residue film to hold up.
|> >How many revolutions do you think it can handle and why?
|> 
|> I think my previous couple of paragraphs represents the justification for
|> my claims with respect to the ability of a thin oil-film to hold up.
|> Where's the flaw in my logic?

Do you think the thickness, and properties of the film in those systems
is similar to the properties of a residue film in a car that has been 
sitting for many hours?  That would be a pretty big flaw in logic.  


|> >|> If you're using a good oil then the viscosity should not change appreciably
|> >|> between cold and normal engine operating temperature - hell, that's why we
|> >|> have synthetics and viscosity improving additives.  Oil pressure is
|> 
|> >What kind of logic is this...you're arguing against yourself.  Synthetics
|> >are designed to get rid of the problem you said doesn't exist?
|> 
|> You've lost me again.  I've never argued against using a good oil and it's
|> always been my assertion that a good oil provides all the protection you
|> need at startup time.  I never at anytime said you shouldn't use oil in the
|> engine!

Huh??? You said we have synthetics so that viscosity will "not change
appreciably between cold and normal engine operating temperature".  But
viscosity additives already take care of that problem...so your
explanation for the existence of synthetics doesn't make sense.  

BTW-lubricant makers make the viscosity vs. T curve as flat as possible, but
it is not flat.  


|> >The properties of an engine oil change over time with oxidation,
|> >particulate loading, acidification, molecular breakdown, etc.
|> 
|> That's right, but if you perform regular maintenance (which I've always
|> advocated) then a good quality oil will still be well within acceptable
|> limits when it is changed.  Are you suggesting that if we fit a pre-lube we
|> can forget about changing the oil (until it runs dry of course because
|> we're not allowed to top it up :-)

No.  Again, your description of regular maintenance is deficient.  Regular
doesn't cut it.  It should be based on oil condition, not on any regular
interval.


|> >|> required to provide adequate lubrication when the engine is
|> >|> operating at its maximum rated performance. I think if you compare
|> >|> the bearing loads at maximum rated RPM driving the highest possible
|> >|> load then you'll find loadings which are several orders of
|> >|> magnitude higher than those encountered at startup.
|> 
|> >Of course, that is why oil pressure and leading edges of film advance
|> >are needed to counter the load.  At startup you have a thin film which is
|> >no where near as able to protect as a pressurized fluid.
|> 
|> But if the loadings are several orders of magnitude lower - the amount of
|> protection required is reduced accordingly (perhaps not in a linear fashion
|> but near enough that it doesn't matter).

And what do you base this on?  Show me the magnitudes of the numerator and
demominator so I can see that it doesn't matter.


|> >|> Again... my query - can someone quantify the scale of start-up wear?
|> 
|> >This is actually probably the only place where Slick-50 can be believed.
|> >Start up wear is on the scale of 500 miles of highway driving wear.
|> 
|> So if I start my engine 4,000 times (twice a day for say 5 years), I've
|> done the equivalent of 200,000 miles of driving?   

No.  Not because I am taking back my statement, but because your calculator
doesn't multiply very well. 

Driving a car with a warm engine, with clean, good oil causes very little wear
on a flat highway at constant highway speeds causes extremely light wear.  If
you could do this without stopping your engine you could expect 2,000,000 miles
out of your engine.  


|> Getting back to my old Honda - I owned it for ten years, during which time
|> it would have been started from cold an average of three times per day (4
|> times per day during the week and twice a day on weekends).  That comes to
|> an equivalent of 5,475,000 miles of startup wear PLUS the 190,000 miles of
|> actual running for a grand total of 5,665,000 miles of wear.  Are you
|> serious????  

I see your calculator is working again!

Yes. Quite.  Anyone well acquainted with tribology of automotive 
engines you would not be surprised.  The actual wear factor depends
not only on how many times you started your car, but how the T ramped
up, and how long the total trip was (was it long enough to boil of
combustion byproducts, etc.).  If you don't idle much, and warm fairly
quickly, the start could be as little as 100 miles of wear, but if
the initial temperature was low, you idled to warm, you take a very short
trip, and your oil is average (not a synth) wear can be 1000 miles/startup.


|> Do you still hold that startup wear equals 500 miles of highway driving
|> wear - did my Honda engine really survive the equivalent of over five and a
|> half million miles of highway driving without noticeable wear - more magic?

Not magic.  It only appears as magic to those not familiar with the details
of the technology.  Do you read the tribology literature?


|> >|> I don't follow you. I think it's widely accepted that synthetic
|> >|> oils produce lower rates of engine wear - well nobody's ever
|> >|> disputed Mobil's findings and I'm sure that if their tests were
|> >|> "rigged" there would have been plenty of noise made by other oil
|> >|> companies wishing to protect their own interests.
|> 
|> >I don't disagree with the benefit of using a synth, but I very much 
|> >disagree with using data from the producer of the product as a 'nuff
|> >said' argument.  You must not be a scientist.
|> 
|> No, I'm not a scientist ... but I'm no mug either.  Your quoted benefits
|> simply don't seem to fit with the actual practical results I (and no doubt
|> many others) have experienced.  Unless you're telling me that my Honda

Fortunately you are not at a automanufacturer highering consultants, otherwise
I wouldn't be hired! ;)

|> engine would have lasted for five and a half million miles of highway
|> motoring with pre-lube fitted then your quatitive claims with respect to

No.  I never said a prelube would get you 5 million miles.  I said it would
reduce wear caused by insufficient lube at start up.  It won't reduce start
up wear caused by byproduct aggregation, oxidation, acid attack of engine
metals, etc.  This should be obvious. 

|> startup wear are way off beam, probably by an order of magnitude or more.

When have you measured anything to know one way or the other?
 

|> >I don't sell auto products either, but my observations are from
|> >working with scientists making measurements on these effects.
|> 
|> Ask them to check their figures -- why are my observations (and those of
|> others) so much at odds with the claims you make?  Or perhaps you should be
|> contacting Honda to find out the secrets to their metalurgic magic :-)

Because you don't understand the meaning of your observations and those of
the scientists I mention.  You seem to forget all the mechanisms of startup
wear.  A preluber will not reduce wear that is cause by the oil being below
the various vapor and sublimation points of combustion byproducts, obviously.


|> >|> 300,000Km with no perceptable engine wear - why should I waste
|> >|> money on a prelube or oil additive?
|> 
|> >If you want less wear, then a prelube and preheater will produce less
|> >wear.  Additives are very questionable.  Just because you are happy
|> >with 300Kkms out of your honda doesnt mean that others would like 
|> >500kkms out of our cars.
|> 
|> Oh yea.. how long does it take for the average joe to rack up 500,000Kms?

10-20 years.

|> Will the bodywork still be in good condition at that mileage?  Will you

The body work on my 250kkm 1990 535i and my wife's 290kkm 1986 3 series are
fine.  I did replace my radiator, but no other major replacements, etc.

|> really want to be driving around in a car which is probably 15 years old?
|> Will you still be allowed to (polution laws etc)?  What about all the other

We have a lot of 15 year old cars on the road today.

|> bits which will have started wearing out - CVs, wheel bearings, struts,
|> suspension/steering bushes, alternators, radiator cores, upholstery,
|> electric windows, master cylinders, slave cylinders, etc, etc.  The
|> economics of maintaining a vehicle at extreme age and mileage go well
|> beyond internal engine wear.

I wonder how those people do it...they don't appear rich.


|> For me, 10 years and 300,000Km is fine, keeping a car on the road beyond
|> this point often becomes a case of diminishing return on investment.  All I
|> want is a nice reliable (fast :-) car that gives me time to save up for the
|> next one :-)

Yeah, that 84 Honda was a speedster! 


|> I suspect that we'll have to agree to differ but I do note that a number of
|> other posters have also commented that pre-lubes are a waste of money.
|> Where is the truth - substantiated by "proven fact" rather than bold
|> claims?

It depends on what you want.  I never advocated their value, but only
their effect.  Of course, in the mind of someone who has not studied
the subject, fact is merely an opinion.



Charles

Charles Musgrave                                   Stauffer III
Assistant Professor of Chemical Engineering        Stanford University
and Materials Science and Engineering              Stanford, CA 94305

Visiting Faculty 1996-Caltech and MIT
Department of Chemisty             Department of Chemical Engineering
139-74 Caltech                     Rm. 501, Bldg. 66, MIT
Pasadena, CA 91125                 Cambridge, MA 02139

From: cbm@athena.mit.edu (Charles Bruce Musgrave)
Newsgroups: alt.autos.antique,alt.autos.camaro.firebird,alt.autos.macho-trucks,
	alt.autos.rod-n-custom,austin.autos,rec.autos.4x4,rec.autos.antique,
	rec.autos.driving,rec.autos.marketplace,rec.autos.misc,rec.autos.rod-n-custom,
	rec.autos.tech,rec.autos.maker
Subject: Re: Slick 50
Date: 30 Apr 1996 15:55:14 GMT

In article <4m3kl0$ltu@mozo.cc.purdue.edu>,
feiereis@colormap.ecn.purdue.edu (John M Feiereisen) writes:

|> In article <4m2h5q$rgi@senator-bedfellow.MIT.EDU>,
|> Charles Bruce Musgrave <cbm@athena.mit.edu> wrote:
|> 
|> >In article <4ljjhj$bte@rock.me>,
|> scsulliv@mtu.edu (Scott C. Sullivan) writes:
|> 
|> >|> Charles Bruce Musgrave wrote:
|> >|> > a) You should never top off the oil.
|> >|>      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|> 
|> >|> I disagree.  It the oil is low, and you are still within
|> >|> the 3000 mile interval, top it off!
|> 
|> >You should fill your oil to some intermediate point on the
|> >dipstick indicator.  The term 'top off' is a poor choice
|> >of words and leads to many people filling their oil to the
|> >top of their crankcase.  Unfortunately the term is widely
|> >used and misunderstood.
|> 
|> Er, 'top off' almost universally refers to adding oil to bring

'Almost universally?'  Sounds like you need a more universal 
definition.

|> the level to the top mark on the dipstick.  Only an idiot would
|> keep pouring oil in until the engine was 'full'.  (How much would
|> that take, anyway.)

One of the greatest challenges in modern technology is writing
instructions that your average Joe can understand and not
second guess.  Do you know how many people overfill their oil?
A lot.


|> Ideally you should fill your crankcase to the top mark on the
|> dipstick.  The upper and lower marks on the dipstick bracket
|> the region which the manufacturer has determined is safe.  Too

Safe meaing some mean time to failure which is within reasonable
limits as determined by the auto maker.  I give my car a small 
extra safety margin.

|> much oil and you run the risk of 'whipping' the oil with the
|> counterweights on the crankshaft.  Too little oil, well, obvious.
|> The more oil you have in your crankcase (up to the top mark), the
|> more oil is available to suspend particulates, etc., effectively
|> 'diluting' the crud.

If you change your oil intelligently, use a good airfilter and change
it when needed, use a good oil filter, don't idle your car up to warm,
don't take a lot of short (less than 10 miles) trips, use a good oil
or better yet, a synth or synth mix, don't drive on dirt roads,
or through dust storms, etc. you should be nowhere near your particulate
loading capacity at 5,000 miles.  


|> Charles, in an earlier post in this thread you referred to 'spikes'
|> in the wear metals in the oil after startup.  How were these wear

Spikes of the engine metals in the oil after startup.  The metals
were measured and recovered in several ways.  One was to pyrolize
samples and run the vapor through a QMS, or use scanning electron
spectroscope.  The metals were also recovered through a simple 
distillation process.  
 
|> metals measured?  Also, how did you come up with your '500 miles
|> of wear each time your engine is started'?  (Yeah, yeah, you said
|> you 'normalized', etc.  How was it measured?)

Samples of oil were taken from a warmed engine that was running
at typical highway speed load and speed.  The metal contents were
measured by the same process as above and then the integrated 
spike was compared to the amount of metal from the simulated
highway measurement.  The various lubricants that were tried
had various metals (Mo, Zn, etc) in them to start with and 
were used as a check on the process.  I am not an experimentalist,
nor the technician who actually turned the nobs, but this is
the basic procedure that was used.



Charles
cbm@mit.edu
cbm@wag.caltech.edu
charles@chemeng.stanford.edu
http://www-leland.stanford.edu/group/chemeng/

From: cbm@athena.mit.edu (Charles Bruce Musgrave)
Newsgroups: alt.autos.antique,alt.autos.camaro.firebird,alt.autos.macho-trucks,
	alt.autos.rod-n-custom,austin.autos,rec.autos.4x4,rec.autos.antique,
	rec.autos.driving,rec.autos.marketplace,rec.autos.misc,rec.autos.rod-n-custom,
	rec.autos.tech,rec.autos.maker
Subject: Re: Slick 50
Date: 30 Apr 1996 16:05:53 GMT

In article <4m3r9h$a68@news.esper.com>, ccoles@esper.com writes:

|> >You should fill your oil to some intermediate point on the
|> >dipstick indicator.  The term 'top off' is a poor choice
|> >of words and leads to many people filling their oil to the
|> >top of their crankcase.  Unfortunately the term is widely
|> >used and misunderstood.
|> 
|> 	You must be the only guy I've every heard of to mis-interpret the

You are the only guy I know who puts a hyphen in the middle of words
for no reason at all ;)

I know how much oil to put in my car, but quite a few
people fill their oil way above the top indictor on
the dipstick. 

|> term. Before you realized it, just what did you think the little lines
|> on the dipstick were for? Most Owner's Manuals describe little things,

Obviously people must sometimes misunderstand their manuals or
never read them in the first place...otherwise we wouldn't
see all the overfilled engines that we see.

|> like checking oil, changing tires, and even checking fuses.

Maybe you should talk to some of the people who write the
manuals and see what they think about it.



Charles

From: cbm@athena.mit.edu (Charles Bruce Musgrave)
Newsgroups: alt.autos.antique,alt.autos.camaro.firebird,alt.autos.macho-trucks,
	alt.autos.rod-n-custom,austin.autos,rec.autos.4x4,rec.autos.antique,
	rec.autos.driving,rec.autos.marketplace,rec.autos.misc,rec.autos.rod-n-custom,
	rec.autos.tech,rec.autos.maker
Subject: Re: Slick 50
Date: 1 May 1996 19:24:09 GMT

In article <mmathys-3004961909520001@sl11.tic.bismarck.nd.us>,
mmathys@tic.bisman.com (Mark Mathys) writes:

|> In article <4m5d52$32n@senator-bedfellow.MIT.EDU>, cbm@athena.mit.edu
|> (Charles Bruce Musgrave) wrote:
|> 
|> 
|> Was there a reason you didn't use something like total ICP? 

I didn't do the experiments and they were several years ago so 
I don't know all the reasons why the methods used were prefered.
It could have been as simple as they worked, and were not being
used in any other study at the time and so were available.


|> Which metal did you look at and what were the typical levels? How do you

It depended on what engine test alloys were used.  If Ni or Chrome
were involved, we looked for them.  Cu and Fe were the most common
metals involved, but depending on whether some kind of nitrogen
ion implantation or c-BN or diamond film were involved, the
materials could have been pretty standard besides the film
or implant.

|> check the process by examining the additive metal Mo and Zn? Please give

We knew how much Mo and Zn were in the lubes so with each test if we
saw more or less the same value (if they were not part of the engine
material) we knew the machine was working about right.

|> more information as I am very interested in this topic and would like to
|> know how you determined that there was significant wear at startup when
|> even at normal oil change the levels of many metals are near zero ppm.

Depends on what you consider significant.  In absolute terms it seems
very small, in relative terms (relative to wear rate at ideal conditions)
it is quite large.

Your numbers don't seem to jive with the amounts I have seen.  Where
did you get the numbers?  As a guess to what the number should be
you can calculate the typical engine surface area times a typical 
wear over a period of time and get a volume of worn away material 
which is quite a bit bigger than one millionth of the total volume 
of oil used in your car over that period. 



Charles

From: cbm@athena.mit.edu (Charles Bruce Musgrave)
Newsgroups: alt.autos.antique,alt.autos.camaro.firebird,alt.autos.macho-trucks,
	alt.autos.rod-n-custom,austin.autos,rec.autos.4x4,rec.autos.antique,
	rec.autos.driving,rec.autos.marketplace,rec.autos.misc,rec.autos.rod-n-custom,
	rec.autos.tech,rec.autos.maker
Subject: Re: Slick 50
Date: 2 May 1996 22:13:20 GMT

In article <4mb1km$d5m@mozo.cc.purdue.edu>, feiereis@font.ecn.purdue.edu
(John M Feiereisen) writes:

|> In article <4m8i4k$aj4@senator-bedfellow.MIT.EDU>,
|> Charles Bruce Musgrave <cbm@athena.mit.edu> wrote:
|> 
|> >In article <4m825p$h7j@mozo.cc.purdue.edu>,
|> >feiereis@colormap.ecn.purdue.edu (John M Feiereisen) writes:
|> 
|> >|> If you can show *any* effect on MTBF of oil level between the
|> >|> top and bottom marks I'd be surprised.  If you could, I'd be
|> >|> willing to bet the optimum level is at the top mark.  Can you
|> >|> give any reason why it would be otherwise?  (And let's leave the
|> >|> idiot-proofing out of it.)
|> 
|> >A lower thermal mass of the oil.  The system reaches operating
|> >temperature faster, giving combustion byproducts less time to 
|> >aggregate and thus giving them a smaller average size.  You also
|> >get a slightly lower oil pressure and so a longer fatigue limit
|> >for your seals. 
|> 
|> Er, the thermal mass of a quart of oil is insignificant in comparison
|> to the thermal mass of the engine itself.  I'd be quite surprised if

Kind of like the additional particulate loading capacity you suggested
by filling to the top of the line would be insignificant?  If you
were going to bring up effects on that scale, why would you have 
a problem when someone else also does?

|> you could see any difference in the temperature vs time curve after

I would think that given the complicated heat transfer in the
system (convection, flow, conduction through various materials
and through complicated geometries, etc) and not knowing the 
particular system, flow rates, peclet numbers, etc. that this 
would be something that you wouldn't profess to strongly.  
What temperature curve are you talking about exactly? 

|> startup due to oil level.  Also, how would oil level between the marks
|> affect oil pressure?  How would oil pressure affect the fatigue life of
|> your seals? What seals are we talking about?

If you have a higher stress imposed periodically you almost
always get a shorter fatigue life.  I suppose you are not a 
mechanical or materials engineer, but this is taught to 
junior MEs and MSEs.


|> >|> Believe it or not, both the top and bottom marks on the dipstick
|> >|> already have decent safety margins built into them.
|> 
|> >Were the guys who picked the separation for the marks the same
|> >guys who put picked the line seperation in the Fords that 
|> >catch fire?  
|> 
|> Er, Charles, that's an ignition switch problem.  The engine goes
|> under the hood.

Er, John. Are you trying to say that engineers who work on ignitions 
make mistakes in choosing the distances to but to lines apart, but
not in where to put two lines on a dipstick?  

|> >Spike metal concentration versus time after startup.  But the
|> >oil was continuously refreshed so the total wear due to start
|> >up was the integrated area minus the base line wear.
|> 
|> Pretty impressive.  Statistically valid wear measurements on-line
|> using a once-through lubrication system and oil analysis.  I assume
|> you've published this.  This is impressive.

I only consulted in the process.  Believe it or not most scientists
in the auto industry spend more time trying to beat their competitor,
rather than publishing.  The only non-proprietary research that was
published as a result of these interactions was on a theoretical study
of growing diamond films (GM was looking at various tribological
coatings).  


|> >|> So, you were simply measuring the wear metals content of the oil.
|> >|> Were you in any way able to quantify the *difference* in wear metals
|> >|> before and after a startup sequence?  There's a lot of 'bounce' in
|> >|> wear metals oil analysis.  Getting a statistically valid difference
|> 
|> >Depends how careful you are doing it.  
|> 
|> That's a good point.  However, if a test is only reliable to within
|> X percent, no matter how careful you are, you're not going to get
|> results better than X percent.

Yes.


|> >|> due to startup sounds like quite a feat.  Maybe you could direct me
|> >|> to an SAE paper?
|> 
|> >Not much of a feat really.
|> 
|> Quite a statement from someone who has said that he's not an
|> experimentalist.  I am an experimentalist and have had quite a bit of

Not an experimentalist any more.  

|> experience with lubricants and lubricant testing.  I've even had a bit

I'd like to read your publications from that experience.  Could
you direct me to your published work in the area?

Where did you get all that experience?  Do you have some publications
I can check out or maybe your thesis?  When you say 'quite a bit of
experience' do you mean compared to the PhDs I worked with who have
been at it for 20 years?

|> of exposure to the measurement of extremely low wear rates in an engine
|> on-line using a radioisotope tracer technique.  Measurement of such low

Sounds interesting.  Where did you publish this work?

|> wear rates is not as easy nor as accurate as you apparently have been
|> lead to believe.

You apparently wouldn't know since I haven't claimed any numerical
accuracy nor any quantitative description of the effort required.


|> >Tribology studies routinely measure wear of extremely small scales.
|> 
|> I'll agree with this.  But I'd still appreciate a pointer toward some
|> publication describing the technique you described.  This sounds like
|> big news.

The techniques have little to do with tribology.  It is a much
more general technology for seperations and low limit detection.
Chemical engineers are actually quite good at distallation.
How much do you really think the auto makers publish about their 
methods?  There is a little difference between academia and 
industry in terms of how much engineers are allowed to divulge.



|> >If your rate is extremely small
|> >then you go to AFM, or SEM and look at surface morphologies, etc.
|> 
|> Pretty tough to do on-line, eh?

No kidding.  Ever use an AFM or STM?  I built an STM once.  You 
definitely don't want to use in oil.

|> >Bromine is often used in organic synthesis and depending on the 
|> >lubricant maker, often ends up in lubricants in small quantities.  
|> 
|> And if you can even detect it above the noise in the IR or ICP, I'd
|> be impressed.  Much less levels that would form detectable levels
|> of HBr.

IR can be rather useless in a complicated multi-component 
system.  If that is what you try to use for detection in 
these systems then I understand why your accuracy isn't
good.  When did I say we detected or looked for HBr?  


|> >|> caused by metal to metal contact that occurs before the hydrodynamic
|> >|> films are established -- I've never heard of acidic corrosion being
|> >|> considered as part of the startup wear.
|> 
|> >I mentioned in an earlier post about lag in the setup of the 
|> >hydrodynamics required to keep surfaces apart.  In addition
|> >to that effect, startup chemistry causes other wear mechanisms
|> >which although not generally lumped into the idea of start up
|> >wear, are in fact parallel mechanisms which account for a 
|> >signficant fraction of wear in typical engines.
|> 
|> Please describe how this 'startup chemistry' differs from the
|> chemistry during normal, steady-state operation.  Yes, yes, I
|> know that cold oil allows crud to condense into the oil.

Good, so you agree that cold starts cause additional wear due
to crud buildup.

|> But assume you have an engine that is at operating temperature
|> and is shut down long enough for the oil to drain back into the
|> pan but not long enough for the oil to drop significantly in
|> temperature, then restarted.

If you start a warm engine, the additional byproducts from
the initial inefficient combustion are boiled off quickly.
In this case the cold start mechanisms I spoke are not active.



Charles

From: cbm@athena.mit.edu (Charles Bruce Musgrave)
Newsgroups: alt.autos.antique,alt.autos.camaro.firebird,alt.autos.macho-trucks,
	alt.autos.rod-n-custom,austin.autos,rec.autos.4x4,rec.autos.antique,
	rec.autos.driving,rec.autos.marketplace,rec.autos.misc,rec.autos.rod-n-custom,
	rec.autos.tech,rec.autos.maker
Subject: Re: Slick 50
Date: 3 May 1996 13:32:35 GMT

In article <DqAL0t.L85@watserv3.uwaterloo.ca>,
csnyder@sciborg.uwaterloo.ca (Clarence Snyder) writes:

|> Re: pre-lube, Slick 50, synthetic, etc.
|> 
|> More wear is caused on today's engines by hot, hard running with 5w?
|> weight oils than is caused ar start-up over the life of the car. If a

Not on my car since I don't use a 5w.

|> car is only run for short periods of time, never warmed up, and the
|> oil is not changed on an accelerated cycle, then wear will be a
|> problem and these measures may make a noticeable difference.  The use
|> of 20W40 or 20W50 oil in warm weather, changed at reasonable frequency
|> of 4 times a year or every 3000 miles max, will allow most of today's

The 3000 mi max number is meaningless.  It depends on how you drive
and the conditions under which you drive.  If you drive 3000 miles
on dirt roads your changing your oil too infrequently.  If you commute
100 miles a day at highways speeds and use a synth oil and have a
good filter you can go way beyond 3000 miles before approaching the
particulate loading limit.

|> engines to run over 200,000 miles without wear related failure. The
|> camshafts, lifters, and timing chains are the first parts to fail due
|> to lubrication on today's engines. In 10 years with Toyota , /at a

Depends on what you call failure.  There is catastrophic failure through
fracture and there is slow degradation through wear.  

|> dealership servicing well over 1000 vehicles, I did not experience ONE
|> lubrication related failure on vehicles routinely serviced by my

So those engines had the same vacuum gauge readings after 200,000 miles
as they did when new?

|> staff. This was in Ontario Canada, where we get extreme cold in the
|> winters, where 10W40 oil was generally used, and some extreme heat in
|> the summer, where we used 20W50.
|> I did replace camshfts, timing chains, bearings, and rings on engines
|> using the recommended 5W30 oil, and changed on extended intervals of
|> 10,000,miles etc. Say no more?

Say more...are you saying the cars you serviced showed no wear degradation
whatsoever after 200,000 miles?  Did you compare output or measure 
compression over time and find no changes?

Charles