2.15.1. Service conditions of engine oil
Depending on service conditions engine oils are exposed to rather big variable loadings. Therefore it is very important to establish influence of service conditions on lubricants precisely.
In the engines working a long time at high turns, or full loading, oil reaches high temperatures.
Under the influence of high temperatures and oxygen of air, oil begins to be oxidized.
Products of oxidation condense oil, especially mineral, and can be deposited in the form of varnish coverings on the top parts of pistons, in flutes of piston rings and on cores of valves. It can lead to a zakoksovaniye of plates of valves.