Oil system myths

I actually don't understand the whole pressure differential argument going on here. and I'm too lazy to go back and try to dig it out. Is someone arguing that suction doesn't occur or?

On the dry pan issue, I think we can all agree that running a quart or two low will result in a deficit of oil available for the pickup to suck. So it's fairly easy to see how changing to a HV/HP pump can create a similar mismatch. In other words, it turns an adequate sump into an inadequate sump.

In recent engines, when I've used a HV pump I've swapped the spring out to the standard part first. I think the added capacity (volume) is OK....the added pressure, more debatable.