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On 5/24/2020 5:05 PM, Bob Johns via Fot wrote:
> Someone was wondering when detergent oils were initiated. I grew up
> right down the street from the Kendall Refinery, and the addition of
> detergents was a big deal. The detergents addition to old curded
> engines was a problem as the curd could-would break loose and plug up
> the oil pump screen. Any way, as I remember the switch over was
> 1951/1952 period. It is hard to find non-detergent these days in the
> better grades of oil.
The problem was not just plugging up oil screens. Engines of the time
used babbitted bearings, which were sealed in place with paraffin-soaked
wicking and similar materials that became carbonized as the hot metal
was poured. Detergents dislodged all that carbonized material and,
oops!, what little oil pressure such engines had went away.
Detergents were introduced when manufacturers upgraded to shell bearings
(which were greatly refined during the war years in aircraft engines).
Detergents tended to keep particles suspended in the oil, which
minimized the chance of them becoming embedded in shell bearings, which
was not so much a problem with babbitt metal. The tin in babbitt metal
was soft enough (and thick enough) for them to get pounded down so they
didn't stick up much from the surface, thus minimizing the damage to
often unhardened crankshafts. The layer of soft metal in shell bearings
is very thin, so the prospect of something getting stuck in them and
being available to wear the crank required rethinking the oils used.
I suspect that the changeover to detergents was accompanied by the same
sorts of problems that the changeover to synthetics presented. If the
engine is designed for the new oils, no problem. If it wasn't, well,
/caveat emptor /(my father, IIRC, blew up two engines in his `46
Plymouth in the space of eight months around the time detergents became
available). In the late `70s, I remember reading some horror stories
about engines converted to full synthetics that burned bearings because
the synthetics ran out of the bearings a lot more quickly, with an
attendant loss of oil pressure. Around the same time, I worked with a
guy who raced snowmobiles along with his brother. He thought he'd try
Mobil1, thinking he'd get another horsepower or so. First time out,
burned a bearing. But, his engine had some hours on it, so they tried
it in his brother's sled the next weekend, which had a fresh engine.
Burned a bearing. Engines designed for the stuff ultimately had tighter
clearances and higher-volume pumps. Still remember some nitwit Navy
lieutenant screaming at me that "jet engines used synthetics," so why
couldn't he use it in his Toyota Celica (this after complaining about
noisy operation only after he converted to Arco Graphite, which at the
time was something like 0W-15... in Florida, in the summertime--its hot
viscosity was less than water). Trying patiently to explain that it's
fine if it's designed for that oil and pointing to the owner's manual
just didn't work....
Cheers.
--
Michael Porter
Roswell, NM
Never let anyone drive you crazy when you know it's within walking distance....
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<div class="moz-cite-prefix">On 5/24/2020 5:05 PM, Bob Johns via Fot
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:B76E099A8E2C428F854D281B0E81BC84@DESKTOPF2062B6">
<meta http-equiv="content-type" content="text/html;
charset=windows-1252">
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<div style="FONT-SIZE: 12pt; FONT-FAMILY: 'Calibri'; COLOR:
#000000">
<div>Someone was wondering when detergent oils were
initiated. I grew up right down the street from the Kendall
Refinery, and the addition of detergents was a big deal.
The detergents addition to old curded engines was a problem
as the curd could-would break loose and plug up the oil pump
screen. Any way, as I remember the switch over was
1951/1952 period. It is hard to find non-detergent these
days in the better grades of oil.</div>
</div>
</div>
</blockquote>
<p><br>
</p>
<p>The problem was not just plugging up oil screens. Engines of the
time used babbitted bearings, which were sealed in place with
paraffin-soaked wicking and similar materials that became
carbonized as the hot metal was poured. Detergents dislodged all
that carbonized material and, oops!, what little oil pressure such
engines had went away.</p>
<p>Detergents were introduced when manufacturers upgraded to shell
bearings (which were greatly refined during the war years in
aircraft engines). Detergents tended to keep particles suspended
in the oil, which minimized the chance of them becoming embedded
in shell bearings, which was not so much a problem with babbitt
metal. The tin in babbitt metal was soft enough (and thick
enough) for them to get pounded down so they didn't stick up much
from the surface, thus minimizing the damage to often unhardened
crankshafts. The layer of soft metal in shell bearings is very
thin, so the prospect of something getting stuck in them and being
available to wear the crank required rethinking the oils used.</p>
<p>I suspect that the changeover to detergents was accompanied by
the same sorts of problems that the changeover to synthetics
presented. If the engine is designed for the new oils, no
problem. If it wasn't, well, <i>caveat emptor </i>(my father,
IIRC, blew up two engines in his `46 Plymouth in the space of
eight months around the time detergents became available). In the
late `70s, I remember reading some horror stories about engines
converted to full synthetics that burned bearings because the
synthetics ran out of the bearings a lot more quickly, with an
attendant loss of oil pressure. Around the same time, I worked
with a guy who raced snowmobiles along with his brother. He
thought he'd try Mobil1, thinking he'd get another horsepower or
so. First time out, burned a bearing. But, his engine had some
hours on it, so they tried it in his brother's sled the next
weekend, which had a fresh engine. Burned a bearing. Engines
designed for the stuff ultimately had tighter clearances and
higher-volume pumps. Still remember some nitwit Navy lieutenant
screaming at me that "jet engines used synthetics," so why
couldn't he use it in his Toyota Celica (this after complaining
about noisy operation only after he converted to Arco Graphite,
which at the time was something like 0W-15... in Florida, in the
summertime--its hot viscosity was less than water). Trying
patiently to explain that it's fine if it's designed for that oil
and pointing to the owner's manual just didn't work....</p>
<p><br>
</p>
<p>Cheers.<br>
</p>
<pre class="moz-signature" cols="72">--
Michael Porter
Roswell, NM
Never let anyone drive you crazy when you know it's within walking
distance....</pre>
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