Drain valves versus plugs versus suction

[Darringer, Chris]

I believe there are two separate things happening to your oil over time.
The first is the build up of contamination in the form of particles (small
bits of metal, dirt, etc.).  A filter's job is to reduce this form of
contamination.  The second is reduced viscocity that comes with high
temperatures.  The components of oil are chemically altered in a way that
slowly reduces their ability to lubricate.  The oil is also a detergent, so
it is acumulating lots of other contamination in solution.  A filter does
little, if anything, in reversing these effects.  The only way to eliminate
this second kind of contamination is through an oil change.

If you spend three days at the track (with fresh oil and a filter) cooking
your oil at 130 degrees, I would guess that you have reduced its viscosity
considerably without introducing too much more fiter-able contamination.  In
this kind of scenario, it might make sense to just change the oil.  (I would
change the filter too, though - just a little extra time and money).

Chris
'90 80q

> Good point here Javad.  As with any system using a filter, the substance
> being filtered doesnt need to be changed as often as the filter does.  The
> main reason for the filter being, keeping the substance being circulated
> cleaner.  Changing the oil more than the filter certainly wont hurt
> anything
> as long as your getting the filter changed at the correct intervals, but
> techinically your doing it backwards. :)