I like the micron data on that chart ..but the tests are still flawed in duplicating the effects in an engine. A MUCH better indicator is pressure drop at a FLOW standard. This, like Bob's test, appears to use a standard pressure ...which, if you see like pressure on any engine, is independant of the filter media (total system downstream restrictions and pump output dictate this). You will see a standard "starting cycle" where the oil pump will typically pump a given volume of oil. That volume of oil will be pumped regardless of what you have for a filter.
There's also the factor of "impedence" to flow at such low temps. My Amsoil bypass, in parallel with my ff (no restrictor valve) has virtually NO FLOW at start up ....but flows more freely at operating temp. What the heck does this show, you ask? Well let's for a moment suggest that all the flow differentials that we see on the study may or may not have a lot less "difference" at a higher "operational" temp. We don't know. Expand this to cover bypass valves and all the other stuff. That is, although a healthy media shows LOW flow AT a given pressure AT a given (LOW) termperature when compared to another ...that difference my be negligable at operating temperature (downstream restrictions take precendence).
If I would do this test (had the means) I would manage a fixed pump output (rpm and therefore gpm) and then use whatever fluid necessary to flow freely at the temperature that I would have it at that would simulate operating temperature (some light weight oil that has a 70 degree SUS that would be typical of ANY motor oil @ 212 degrees).
Does anyone else see the validity of this methodology in filter testing? That is, for a moment pretend to try and assist me in sucessfully showing how this type of test is superior and NOT just knocking down some of my "slightly less then perfect" givens (in otherwords the point not the content).
[ May 04, 2004, 10:51 AM: Message edited by: Gary Allan ]
