<VV> Re: Curious oil practices

[Thesuperscribe at cs.com]

Billy Ray,

I'm not an engineer but I write about this stuff sometimes, so I'm guessing 
that the old guy's don't-drain-but-change-the-filter practice worked because 
the oil stayed pretty clean. Three thousand miles in moderate to light-duty 
service was/is not enough to wear out the oil, and changing filters at that point 
was enough to take out any accumulated dirt, etc. Adding a quart or so at that 
time replenished the additive package while further freshening the oil in the 
crankcase.

Some truckers now go much farther between drains by using bypass filtration 
-- an extra filtration device which continuously cleanses small amounts of oil 
so that eventually all oil in the crankcase is purified. Oil analysis confirms 
that such oil in a big on-highway diesel can go 25,000 to 50,000 miles or 
more without change. However, filter elements are changed periodically. 

In 1980 or so I did an article about a guy who ran a few dump trucks but 
didn't want the mess and oil-disposal problems from frequent changes (10,000 miles 
was then a common  drain interval, and some still do it that often). He had 
one Cummins 855-cid-powered truck that had gone more than 400,000 miles without 
a drain. But he did change the extra filter element (basically tightly-wound 
paper toweling in a cannister) about every 12,000 miles and poured in a gallon 
of oil to make up what the dirty element took out. He was also careful with 
his air filters. Regular analysis showed all levels of impurities, including 
wear metals, were well within safe limits.

Right now I am doing essentially the same thing with the 110 engine in my '64 
Monza. I haven't drained the oil in several years, but do change the filter 
about once a year. In a year I drive maybe 500 to 1,000 miles -- and leak five 
to 10 quarts of oil, which of course I replace with new oil. So, ha ha, it's 
getting an oil change every 500 miles, and I don't need oil analysis to tell me 
that the engine's almost certainly safe. 

Now, when I get those O-rings replaced on the pushrod tubes....

--Tom Berg

*** 

In a message dated 7/5/2005 6:04:03 PM Pacific Daylight Time, 
virtualvairs-request at corvair.org writes:


> Date: Tue, 5 Jul 2005 19:15:46 -0500
> From: "Billy Ray Richter" <brichter at gtcom.net>
> Subject: <VV> curious oil practices
> To: <VirtualVairs at corvair.org>
> Message-ID: <200507060015.j660FlFw002938 at tiger.skiblack.com>
> Content-Type: text/plain;    charset="us-ascii"
> 
> I spent 35 years in a paper mill.  Lots of lubricants and oils especially.
> Lots of funny practices concerning oil in vehicles among fellow employees.
> One fellow never changed oil, every 3000 miles he changed filters and added
> oil back to the full level.  I knew him 30 years until he died and he never
> had problems with his oil.  Kept his cars for years and always had over
> 100,000 miles on them.  I never had the nerve to try this.  I always had a
> lot of fun telling the oil vendors who visited me about his oil filter
> changes.  We used synthetics in gearboxes that were in extremely hot
> environments and always lowered the temperature by at least 20 degrees.  The
> reps from the oil companies always told me that if you went to synthetic oil
> after you had used dino oil for some time then the vehicle would probably
> start using oil.  Something to do with cleaning out the gunk sealing cracks
> and crevices.  The only thing consistent about oil recommendations and
> theories is the inconsistency.  No one seems to agree on any one procedure
> or superior oil.  I just use a good oil and change it regularly.  Try to
> keep the temperature down and don't burn it.  
> 
> 
>