Attention: TDR Forum Junkies Book Bits: How Hard is Soot?
From "The Oil Analysis Handbook"
Soot is abrasive. Intuitively one might think of carbon black as being relatively 'soft', however soot particles, in any form, are harder than steel. Engine oils are formulated with additives that keep soot in suspension and stop it from agglomerating but, as with other additives, they are sacrificial. Once a certain level of soot loading is reached (typically around 3 percent by mass for most engine oils), the soot particles will no longer be able to be carried by the oil and sludgy deposits will form. Not only is soot abrasive but it also causes the viscosity of the oil to increase.
from this week "Lube-Tips Newsletter <newsletters@noria.com>"
Bob Weis
From "The Oil Analysis Handbook"
Soot is abrasive. Intuitively one might think of carbon black as being relatively 'soft', however soot particles, in any form, are harder than steel. Engine oils are formulated with additives that keep soot in suspension and stop it from agglomerating but, as with other additives, they are sacrificial. Once a certain level of soot loading is reached (typically around 3 percent by mass for most engine oils), the soot particles will no longer be able to be carried by the oil and sludgy deposits will form. Not only is soot abrasive but it also causes the viscosity of the oil to increase.
from this week "Lube-Tips Newsletter <newsletters@noria.com>"
Bob Weis
