Engine Dry Sump System

Additive metal manufacturing is a technology that allows the creation of three-dimensional objects by depositing metal material layer by layer. It also allows the design of parts with complex geometries that would be difficult or impossible to achieve with conventional manufacturing methods. This technique also allows to improve manufacturing finishes by avoiding welding joints between different parts to form a part.

A dry sump system allows to reduce the height of the engine with respect to the lowest point of the vehicle, and therefore the center of gravity of the vehicle.

The combustion engine in a Formula student car can account for 25-30% of the weight of the vehicle, excluding the driver. It is undoubtedly, after the driver, the heaviest element and therefore, its positioning is of great importance. Both longitudinally and transversally, for a good weight distribution, and vertically, for a good center of gravity. The use of a dry sump system helps to reduce the height of the engine position, and thus improve the dynamic properties and handling of the vehicle.

Wet sump systems are much simpler to implement, but wet sump systems can generate pressure losses in the circuit due to oil movement caused by acceleration and braking, and high G-force cornering. In addition, oil temperature can be more difficult to control because it is stored inside the engine, which can affect performance and durability.

Dry sump oil lubrication system has numerous advantages, but it is a more complex system than a wet sump system, which requires more components to operate (scavenge pumps, oil tank, external oil lines, engine adapters, etc.).

Two types of sump design have been considered. The first design reduces the sump height by about 37 mm with respect to the wet sump. This design allows the connections for the scavenge pump to be located on the vertical side faces where the ramp is not located. It includes vertical fins that have a dual function. On the one hand they have an oil cooling function, and on the other hand, they help to give stability when the motor is on a flat surface. It prevents the engine from oscillating vertically.

The second design reduces the height with respect to the wet sump by 53 mm. However, it forces to make the connections with the scavenge pump and the inlet from the oil tank to the internal engine pump through some side of the engine. Forcing to drill the block walls and to mount adapters for the oil lines.

The following image shows a comparison between two models of dry sump for a 600cc engine vs a wet sump, where the 4 liters of oil that the engine needs, goes into it.

In the following image you can see a comparison of the placement of one system versus the other. If you take the chassis as a reference you can see the big difference in a small formula type vehicle.