An engine must be lubricated for smooth, efficient performance, and an oiling system addresses this need. There are two main types of oiling systems, a wet sump and a dry sump.
The wet sump system is typical in most production cars, with the oil sitting in an oil pan reservoir stored beneath the crankshaft. An internal oil pump, which sucks the oil through a tube from the bottom of the pan’s sump, distributing oil throughout the engine. The wet sump system provides the advantage of a simple design, however there are potential issues regarding oil control particularly in modified engines and racing applications.
The large g-forces pulled under acceleration, aggressive braking and cornering at speed:
The alternative, a dry sump set-up, uses two or more oil pumps, and a separate oil reservoir. There are a minimum of two stages, one stage for pressure and at least one stage for scavenge. The pressure stage supplies oil from the bottom of the reservoir into the engine, and the scavenge stage/s remove oil out of the dry sump pan and return this oil (and air) to the reservoir, with the option for adding multiple scavenge stages to ensure maximum oil is scavenged from the engine. The reservoir (tank) controls the flow of oil, removing air bubbles, and sending the oil back to the oil pump to be routed through the engine.
In a dry sump set-up, the oil pump is usually mounted to the side of the engine, and driven by a belt off the front of the engine. It is typically lower than the reservoir, so it is gravity fed, rather than requiring a pump to suck the oil upward, as in the wet sump design, and performs more efficiently as it receives positive pressure on the suction side.
The dry sump set-up is more appropriate for a racing application, compared to the wet sump system, as it provides:
The key documented disadvantage to a dry-sump setup is the added cost and complexity to your engine build, however, from the weekend enthusiast to the professional racer the significant advantages far out way the cost, remember no oil equals no engine!