At what point do I need a HV oil pump
03-22-2014, 11:06 AM
#21
If it is a bypass flow setup of some sort siphoning partial flow away from main flow certainly, like maybe a turbo or ultra high efficiency bypass filtration, but if full flow as I thought most setups typically were how would a HV pump help?
HV pumps go into bypass at a lower rpm given the same bearing clearances, once at the same bypass pressure standard volume and HV are going to push the same amount through bearings and on high rpm motors all that ectra oil in bypass is just getting heated up more, and increasing the likelyhood of cavitation, flooding the valvecovers or draining the pan.
Unless bearing clearances are extra wide using high rpm as the excuse for HV is actually specifically contradictory to reasonable thought because either pump would likely be in bypass long before the higher rpm is reached.
If one stops and thinks about it a HV pump makes more sense on a low rpm motor that never spins the pump fast enough to create extra flow, it will move more oil at those low rpms.
HV pumps go into bypass at a lower rpm given the same bearing clearances, once at the same bypass pressure standard volume and HV are going to push the same amount through bearings and on high rpm motors all that ectra oil in bypass is just getting heated up more, and increasing the likelyhood of cavitation, flooding the valvecovers or draining the pan.
Unless bearing clearances are extra wide using high rpm as the excuse for HV is actually specifically contradictory to reasonable thought because either pump would likely be in bypass long before the higher rpm is reached.
If one stops and thinks about it a HV pump makes more sense on a low rpm motor that never spins the pump fast enough to create extra flow, it will move more oil at those low rpms.
Anytime the area over which the force is to be distributed is increased in one part of the oil system the residual force available to provide pressure to remaining, downstream system is potentially affected. When oil coolers, oil accumulators, or remote filtering units are added to the system they increase, sometimes dramatically, the area over which the force available from the oil pump is to be distributed. This increase is a function of the additional length, diameter, and internal friction associated with the system additions. There is no such thing as system additional that does not consume “force.” The amount of force consumed can be reduced by using adequate line diameters, reducing internal friction, and minimizing length, but the sum is never “zero.”
Whether the modified oil system will benefit from a high volume pump depends on whether the standard volume pump can supply the increased “force” (volume and velocity) required to maintain adequate oil pressure at all operating conditions. Obviously, there can be some point where the standard pump is not being bypassed but is nonetheless incapable of providing the required “force” (volume and velocity) for an expanded oil system.
Last edited by Darkman; 03-22-2014 at 11:25 AM.
03-22-2014, 11:27 AM
#22
I'm no Fluids Engineer, but I do remember reading a Melling publication that said the bypass oil recirculating through the pump actually helps to resist and reduce cavitation in the pump.