Hi volume oil pump vs standard volume pump

moper said
Seriously, if that's how you think it works I'd suggest you need to do a lot more research into the subject.

Goodness.... I'd be happy to hear why it does not do as described. (I think can take it.) People get confused at the name high volume; that describes only the pump. The system's flow volume behavior is not just the pump; it is the pump, the relief spring, and the system's outlets.

I'd suggest starting with an understanding of the behavior of positive displacement pumps; that has a specific meaning. They will try to push an amount of fluid directly proportional to speed regardless of the back pressure. If the amount being pumped exceeds the flow that the system downstream will accept, pressure increases until:

the rest of the system does accept that flow
the pressure goes to a level where something like a relief valve allows the flow to go elsewhere (back to the pump intake in this case)
the pump internal leakages get excessive

In the case of these 2 pumps, the oiling system accepts the flow dependent on the pressure at the output of the pump. If the pump has a lower pressure output due to a lower pressure relief spring, then less oil will flow into the system and less will be available to become windage; that was the point. Both of these pumps will put out enough flow to drive the pressure up to the relief spring pressure at higher RPM's, if they are in good shape and you don't have some excess clearance downstream. The HV will just get there at a lower RPM.

MOPAROFFICIAL said
Same 340, went from 72 hv to m72.....no pressure difference on the gauge what so ever.
I took the advice to ditch it, that it ate almost 10hp by 6000 rpm. I dont bother with hv pumps anymore.

Not sure you meant to say one thing or another on the matter, but the first sentence is what I am trying to explain .... both pumps will push out adequate volume to trip the pressure relief at sufficiently RPM's. The only place that an HV pump will show higher pressures is at lower operating RPM's where the output pressure is below the level of the relief spring.