Saw Garak's post in Mola's latest quiz, and dug this up.
http://oil-additives.evonik.com/sites/dc...obo-reprint.pdf
Interesting bench test versus ageing oil in an operating engine...
Quote:
The test oil is combined with a small amount of iron ferrocene, a soluble iron catalyst, to aid oil thickening. This mixture is then placed in the reaction vessel and is heated to 170°C with vigorous stirring for 40 hours. During this time, a measured amount of nitrogen dioxide, simulating blowby gas and itself a powerful oxidant, is introduced over 12 hours to further catalyze the oxidation, or thickening, reaction. A subsurface feed of air is introduced to supply oxygen. Another extremely important parameter—application of a vacuum—mimics the volatilization of the Sequence IIIGA and lends to further thickening as light base oil ends are removed.
Iron ferrocene is added to the test oil to simulate the catalytic effect of iron found in used oils from wearing of engine parts. Iron has a catalytic (accelerating) effect on oxidation (oil thickening). So, iron ferrocene is added to ROBO test oil to simulate this. Why iron ferrocene? This form of iron is soluble in oil which is important so it can be available to participate in the oxidation (thickening reactions).
Reinforces my belief that varnish is produced in the windage zone of the crankshaft, with hot oil droplets exposed to reactive blowby gasses.
Questions that it raised in my mind
Does it support bypass filtration in keeping metal particles out of the bulk oil, reducing their catalytic action ?
40,000 miles is a big OCI, regardless of make-up.
Does it support the Mobil/Amsoil 12 months regardless of mileage stance ?
e.g.
low miles, probably means more warm-up operation, more blowby per mile, more sitting with these things in sump
versus high miles, where temps and time at temp are high.
http://oil-additives.evonik.com/sites/dc...obo-reprint.pdf
Interesting bench test versus ageing oil in an operating engine...
Quote:
The test oil is combined with a small amount of iron ferrocene, a soluble iron catalyst, to aid oil thickening. This mixture is then placed in the reaction vessel and is heated to 170°C with vigorous stirring for 40 hours. During this time, a measured amount of nitrogen dioxide, simulating blowby gas and itself a powerful oxidant, is introduced over 12 hours to further catalyze the oxidation, or thickening, reaction. A subsurface feed of air is introduced to supply oxygen. Another extremely important parameter—application of a vacuum—mimics the volatilization of the Sequence IIIGA and lends to further thickening as light base oil ends are removed.
Iron ferrocene is added to the test oil to simulate the catalytic effect of iron found in used oils from wearing of engine parts. Iron has a catalytic (accelerating) effect on oxidation (oil thickening). So, iron ferrocene is added to ROBO test oil to simulate this. Why iron ferrocene? This form of iron is soluble in oil which is important so it can be available to participate in the oxidation (thickening reactions).
Reinforces my belief that varnish is produced in the windage zone of the crankshaft, with hot oil droplets exposed to reactive blowby gasses.
Questions that it raised in my mind
Does it support bypass filtration in keeping metal particles out of the bulk oil, reducing their catalytic action ?
40,000 miles is a big OCI, regardless of make-up.
Does it support the Mobil/Amsoil 12 months regardless of mileage stance ?
e.g.
low miles, probably means more warm-up operation, more blowby per mile, more sitting with these things in sump
versus high miles, where temps and time at temp are high.