quote:Originally posted by accobra:
The screen in the pickup is not only to screen out debris but to remove air bubbles from the incoming oil ... which could be generated by overhead oil / vaporizing.
Cavitation is NOT air bubbles in the incoming oil.
Cavitation should not be confused with Aeration.
Cavitation is the inability of the oil to flow into the pump at a rate equal to that at which the oil is being pumped out.
It is a phenomenon that takes place internally inside the pump, if it is taking place no amount of oil in the sump or sump design will have any influence over it.
It is essentially a cavity, a void in the oil, it does not consist of air but rather vacuum. In liquids with low boiling points and high vapor pressures it can contain that liquid in vaporised form.
Motor oil will smoke and catch fire usually before it reaches boiling (more than 300 degrees) so it's vapor pressure even when hot is such that it's viscosity is more of a influence on cavitation.
Cooling the oil will in fact make it worse as the oil at higher viscosity will be more resistant to flowing into the pump and through the pump's ports.
It cannot be observed externally (unless you had a pump and engine made of glass) and it decreases the efficiency of the pump especially as the pump speed increases.
Also increasing the pump size (high volume pump) will make it worse not better. Possibly the reason why many oppose the use of high volume pumps.
I couldn't give two hoots about the finish on the pan.
