Learned a lot here. Thanks a lot.
When does an engine need the most oil?
- Thread starter HawkeyeScott
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Originally Posted By: HawkeyeScott
Learned a lot here. Thanks a lot.
No probs...here's some pics...first is the demand curve of a typical engine...nte, needs more flow as revs rise, but not proportionally more.
The straight line is a normal oil pump, delivers volume linearly, and has to be capped with a pressure relief valve.
The relief valve limits pressure, and thus the excess flow gets returned to the sump, or pump inlet, wasting energy (50-150W, but that goes into heating the oil - 1/15 to 1/5 of a horsepower).
So the manufacturers are now doing variable delivery pumps, like the one on the right below.
At low revs/pressure the spring holds the housing so that the maximum delivery volume is attained per RPM...as the pressure rises with revs, the housing pivots so that the rotor is more central, and delivers less volume.
Learned a lot here. Thanks a lot.
No probs...here's some pics...first is the demand curve of a typical engine...nte, needs more flow as revs rise, but not proportionally more.
The straight line is a normal oil pump, delivers volume linearly, and has to be capped with a pressure relief valve.
The relief valve limits pressure, and thus the excess flow gets returned to the sump, or pump inlet, wasting energy (50-150W, but that goes into heating the oil - 1/15 to 1/5 of a horsepower).
So the manufacturers are now doing variable delivery pumps, like the one on the right below.
At low revs/pressure the spring holds the housing so that the maximum delivery volume is attained per RPM...as the pressure rises with revs, the housing pivots so that the rotor is more central, and delivers less volume.
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