As engine combinations and racing conditions become more extreme, racers often step up to a dry-sump oiling system in both drag and road race applications. That’s because they are the safest and most dependable oiling systems available. They’re popular in any class of racing where the rules allow them, especially where low chassis height is important for good handling. Horsepower gain is maximized in a dry-sump system, because there is virtually no oil in the pan and no internal pump, allowing the windage tray or screen to run the full length of the pan. Other advantages of a dry-sump system include a remotely mounted oil tank for increased capacity, the ability to easily add remote oil coolers, more consistent oil pressure, adjustable oil pressure, improved scavenging, and increased ring seal due to greater oil pan vacuum. A dry-sump oiling system consists of the dry-sump pump itself, which can have anywhere between one to six stages. The stage designation refers to how many scavenge and pressure sections the pump has. For example, a four-stage oiling system would have three oil pickups in the oil pan itself. Each one of these pickups would be plumbed to the three scavenge sections of the oil pump. With this type of oiling system, a full-length windage tray can be used inside of the oil pan and the oil can be stored outside of the oil pan in a baffled dry-sump tank.
Can a wet sump work as well as a dry-sump system? Yes and no. Even though Moroso sells three different series of dry-sump pumps, production and custom dry-sump oil pans, and dry-sump tanks, certain applications are better suited to a wet sump oiling system. On street applications, all but the most exotic and high-performance street cars are better suited to a wet sump system. This is because a dry-sump system adds complexity, cost, more maintenance, and a user that has to be more mindful of what the system is doing. Additionally, in many racing classes dry-sump systems are simply not allowed.
Wet Sump Enhancements
Whether you have a street car, or you’re racing in a class that prohibits a dry-sump oiling system, there are several ways to enhance the performance of a wet sump system. A good place to start is with an oil pan with trapdoor assemblies that keep oil in the pump pickup area during acceleration, braking, and cornering. Likewise, Moroso offers billet aluminum wet sump oil pumps for small- and big-block Chevy engines. These pumps have a mounting area that’s three times larger than a stock pump to prevent braking. They also weigh a pound less, have larger pickups and inlet areas to prevent cavitation, and thrust bearing assemblies that increase housing and gear life due to improved driveshaft axial forces on the drive gear. Lastly, plumbing an oil accumulator into a wet sump system helps ensure a steady flow of oil in the event that the pickup is ever uncovered.
The purpose of a vacuum pump is to remove air, blow-by gases, and other contaminants from the crankcase of an engine. The vacuum pump’s ability to remove the air in the crankcase results in overall engine vacuum. This vacuum increases horsepower by allowing the use of low tension compression and oil control rings. The combination of low-tension rings and crankcase vacuum reduces frictional horsepower losses, blow-by, intake charge contamination, and the potential for detonation. Moroso’s purpose-built racing vacuum pumps offer all these advantages and more, whether the engine at hand is a naturally aspirated small-block or a nitrous-equipped Pro Mod. The components required to install a vacuum pump system are the vacuum pump itself, a mounting bracket, a vacuum pump pulley, a crankshaft drive pulley, a drivebelt, a vacuum pump line kit, a regulator, and a breather tank.