Originally Posted By: SilverFusion2010
I've seen some serious snark directed at M1 because it shows higher iron in UOA.
Could it be an additive of some sort?
I'd missed the above mentioned 'era' of higher UOA iron from M1, here in bitog.
So my comments below might be off, though.
I would reckon it's additive package related , and independent of oil viscosity grades in use and/or operating viscosity,to a certain extent.
To be specific, it's related to a minor (but critical in this context) part of add-packs that offers anti-corrosion/anti-oxidation performance.
Quote:
What wears that releases iron?
Primarily corrosion wear was initiated as a function of operating conditions (eg temperatures) and (lack of performance efficacy of )anti-corrosion/anti-oxidation additives.
This corrosion wear initiation is further 'aggravated' in contacting surfaces ( such as cam lobe/follower and piston ring/liner tribopairs ) subsequently by adhesion and/or abrasion phenomena in boundary lubrication and mixed lubrication regimes.
Corrosion wear in non-contacting surfaces are not as severe in magnitude.
Quote:
Is high iron really a problem? Why or why not?
In this context, the 'initial' part of "high iron phenomenon" is NOT a problem for there is generally zero change in operating clearance of contacting surfaces or.. minimal change, in so far as it's acceptable and well below 'critical threshold' of operating clearance.......
beyond which (meaning the 'final' part of high iron phenomenon) another more destructive phenomenon of fatigue failures sets in that results in exponential increase in wear rate, which leads to increased operating clearance prior to equipment shutdown or components destruction.
The 'inescapeable' phenomenon of corrosion wear in contacting surfaces (of increased surface roughness) in normally operated equipments often results in reduced specific oil film thickness under similar operating environments....
hence shifting (previously) hydro-dynamic and EHL lubrication regimes on Stribeck curve leftwards to boundary lubrication and mixed lubrication regimes........
which leads to my preference for upping a viscosity grade or two (over and above OEM recommendation) in normally operated equipments of 'prolonged' use.
Just my
Don't flame, but educate me please. [/quote]