As a start, I suggest the following:
1) Use an oil that represents the typical viscosity of engine oil at normal operating temperature. That may mean a “thin” oil, or perhaps warm/hot 10W30 etc.
2) Select a representative flow rate (probably around 3-5 gallons per minute) for initial test stand set-up.
I believe the above are absolutely essential to getting data that will lead to correct conclusions about the oil filters tested.
Setting up the test would go something like:
1) Spin on an empty (no filter element) oil filter.
2) Heat up the oil as necessary.
3) Turn on the pump and set the pump RPM to a reasonable speed (1000 RPM?).
4) Adjust the flow control valve (after the oil filter) to achieve the representative flow rate chosen earlier.
5) Hopefully the filter inlet pressure will be around 40-55 psi. If not, the oil pump RPM and flow control valve can be changed to achieve a reasonable inlet pressure. However, when making adjustments to achieve 40-55 psi inlet pressure, make sure the flow rate is still between 3-5 gallons per minute. The pump RPM may end up well above or below 1000 rpm. That’s OK. Having a representative restriction (flow) is more important than pump RPM.
I believe the initial (empty filter) 3-5 gpm flow rate and 40-55 psi reasonably represent a typical engine running down the road.
Now, to test each filter:
1) Make sure the oil is at proper temperature.
2) Spin on the filter being tested.
3) Turn on the pump and run at the RPM set in step 3/5 above.
4) Measure the filter inlet and outlet pressures
5) Measure the flow
6) Don’t touch the flow control valve or the pump RPM. After all, these things are generally fixed in a given engine (pump gearing and engine passages, bearing clearances etc.). And they were initially set to represent an actual engine operating condition.
7) Go back and repeat steps 1 through 5 for each filter.
What you’ll end up with (I think) is flow and pressure data for each filter at an operating point representative of an actual engine. Different filters will likely show some variation in both flow and pressure, just like they would on an engine. And (I think) the purpose of the test is to measure the affects of different oil filters on pressure and flow in an engine.
After gathering filter data in the above manner, it may be determined that cold oil data, dirty oil data, low flow/pressure data (engine idle), or high flow/pressure data (high engine rpm) is also desired. Appropriate changes to the test set-up can then be made to simulate those conditions and gather more data.
My only concern with the test is that the data might not show much difference between filters. Don’t get me wrong, I fully support the test and would like to see the results. However, I wouldn’t be a bit surprised if the variations in flow and pressure between models and brands of “like” filters prove to be rather insignificant.
Oil filter manufacturers design their filters to flow a given amount of oil at a certain pressure drop, and it’s likely that the design goals are nearly the same for all manufacturers. Therefore, I would expect similar flow and pressure data regardless of model or brand of "like" filters tested. If my expectations are wrong
, well, that'll just prove the test that much more useful
.
