Quote:
Originally Posted by spdbrake
Curious on when the bypass valves (aka safety valve) located in oil filters started bypassing oil as part of their day to day job? |
When the differential pressure across the valve exceeds the seating pressure the filter manufacturer designed into the valve. In real life this is most of the time the engine is running. A portion of the
oil Is bypassed and a portion of the oil is filtered
Quote:
Originally Posted by spdbrake
Historically their function has always been to prevent oil starvation in a clogged filter condition.
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That is one of the functions. The other is to bypass the oil volume the filter is incapable of filtering because it exceeds the flow capacity of the filter element. When the flow capacity is approached the differential pressure across the bypass valve causes it to open and bypass the filter element.
Quote:
Originally Posted by spdbrake
I should mention the bypass valve setting like on the Wix 51515R I use which 8-11 psi, is the differential pressure the valve will open at (In psi VS out psi).
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You are correct. As soon as the differential pressure hits that 10 to 15 psi window the filter bypass opens up to drop the pressure by bypassing the excess oil. The unfiltered oil that has bypassed the filter element goes directly to the engine bearings for lubrication purposes not back to the oil pan — hence the risk.
Ed