This is what a typical dry-sump oiling system looks like. Shown here is a three-stage pump (actually three pumps-one for pressure and two for scavenging). You can have as many stages as you want, depending on how much scavenging you need. Generally, there is one stage for pressure and at least one stage for scavenging. In this application, we have one pressure stage (capped) and two scavenging stages. The scavenge ratio is 4:1, which means it has the capacity to return way more oil than it receives. This means more power because an efficient scavenging system will reduce crankcase pressure.