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Oil testing services (was: Rubber Bushing Lube)

To: mgs@Autox.Team.Net
Subject: Oil testing services (was: Rubber Bushing Lube)
From: mgb.roadster@juno.com (Larry A Hoy)
Date: Thu, 4 Sep 1997 09:30:54 -0600
On Thu, 04 Sep 1997 09:03:38 EDT mgbob@juno.com (ROBERT G. HOWARD)
writes:
>Hi Mike,
........snip....... 
>More seriously, the oil may contain leak and wear evidence, such as 
>antifreeze, tin, lead, copper, etc.  Operators of serious equipment 
>such as aircraft engines, locomotives, trucks and busses take a sample 
>of the used oil and send it to a lab for analysis. Costs about $15 I 
>think.  The lab then reports on their findings. Antifreeze is from a 
>leak. Lead, copper, bronze and tin are from bearings, and so on.  The 
>big operators keep records showing the findings at each oil drain, and 
>will schedule their bearing changes and tear-downs at a time when the 
>wear (hence more of xxx in the oil) reveals an increasing rate of 
>wear.  Many of these operators change oil at intervals that we car 
>drivers would consider way too long, but if they are testing the used 
>oil they have a rational basis for their action.
>  This idea piques my curiosity. If I can get more info on one of the 
>testing services, I'll post the infomation to the list.
>Bob

Typically the reason that the "big engine" guys do the testing and the
rest of us don't is the following. 

A big engine can cost in excess of $40,000.00 and may use 12 to 15
gallons of oil.  If you pay that much for an engine you want to know what
is going on inside it.   A typical oil change can cost $100 - $150
dollars, if you save a few oil changes by testing before you throw good
oil away  you are ahead of the game.

It should be noted that once an engine has been run the oil is used and
will show contamination.  The question is, how much is too much?  The
answer to the question is determined by the type, brand, application, and
unique characteristics of the individual engine, as well as the type of 
lubricant used.  Most  "big engine" fleets will sample oil on a regular
hourly interval and compare recent sample results to previous results. 
This allows them to see trends in engine wear, as well as impending
problems, and determine when the oil has reached the end of its useful
life.  

The sampling is generally done based on the hours the engine has run and
not the miles driven.  The typical big engine has an hour meter which
records one "real time" hour  when the engine is run at 100% capacity for
one hour, if the engine has run at less than 100% capacity for one hour
then something less than one hour is recorded on the hour meter.  Oil
analysis is only valuable if it is done on a regular basis and  the hours
on the oil is considered when looking at the test results.  It would be
expected that less contamination would occur with fewer hours.

Now, having said all this, does it make sense to test the oil in your
LBC?  Some of you may think yes; others, no.  In my humble opinion it
doesn't make sense.  We aren't spending $100 on oil changes, or
$40,000.00 on engines.  If you are concerned about engine longevity just
change your oil (and filter) regularly;  perform routine maintanence, and
maybe not so routine maintenance (remember the main bearing thread!).

If you are inclined to have your oil tested, one  place that can do it is
a local Caterpillar Tractor dealer, they may even have an "in house" lab;
and any dealer that sells trucks or tractors will also be able to do it,
although they may send it out. 

Hope this helps.

Larry Hoy (MGB.Roadster@juno.com)
Denver, CO USA
1969 MGB Roadster
1987 Jaguar XJ6 Vanden Plas
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