Dry Sump Systems Explained And Why You Need One

The oil system is one of the most important features of any car and should never be underestimated or taken for granted. With the sheer volume of moving parts which in turn create a whole tonne of friction, it’s essential that all of the necessary parts stay lubricated and free moving, thus keeping the engine operating at a smooth and efficient level.

When it comes to liquids within a mechanical system like an engine, there are always a couple of general features that resonate throughout. Firstly, there has to be some form of reservoir, somewhere for the bulk of the fluid to sit before being sent away for lubricating duties. The propulsion of the fluid is then performed by a pump which propels the fluid from the storage unit to wherever it needs to lubricate. It gets there by the use of channels that are built in to route the lubricant throughout the engine to the specific areas needing a reduction in friction.

In a traditional oil system, the reservoir/storage unit is called the sump. This is a chamber that lies at the base of the engine underneath the crankshaft, otherwise known as the oil pan. This produces a simple solution for oil storage due to the fact that gravity will always pull the liquid down into the sump from where it can sit and then be redistributed.

Unfortunately, there are some inherent problems that occur from using this method, the first of which being oil starvation. As a car is cornering, the lateral g-force acting on the car will force the oil to lean to one side, sloshing in the opposite direction to travel. If cornering is therefore frequent or constant, the oil continually sloshes to an area of the sump where the oil pick-up cannot access it, meaning a lack of oil reaching the pump so the engine does not receive the amount of oil required to effectively lubricate itself.

The presence of a sump also means that the engine block itself is a very tall, heavy lump of metal that only detracts from the car’s performance due to its placement causing a high centre of gravity.

One way around this problem is a dry sump system.

A dry sump is created by removing the sump from the bottom of the engine block and instead placing an oil reservoir elsewhere in the engine bay. Using some form of container for storage, the oil is then pumped internally to the engine from an external position. This is accomplished using an extensive route of silicone and metal piping that travels from the reservoir to wherever the lubrication is needed.

The external reservoir means that oil starvation is a thing of the past (as long as the pump is fully reliable) so the life span of an engine – especially in motorsport – is greatly increased. The specific routing of the oil by the oil lines means that you can also be very specific with where the lubricant is being applied. A small sump still exists to collect the oil that makes its way to the base of the engine but it is very shallow and the excess oil is quickly scavenged back to the external reservoir.

In terms of the engine block itself, the lack of a large sump on the base of the block means that the engine can be mounted much lower in the car’s engine bay. This puts the dominating weight of an engine block nice and low within the car’s chassis, thus improving the centre of gravity placement, weight distribution and the general dynamic abilities of the car in question. Some manufacturers have gone even further and added active-engine mounts to the block which further manages the engine’s bulk to help performance.

Another simpler method of avoiding oil starvation is baffling. By welding in slats of metal within the sump or onto a metallic sump gasket, the oil will slosh into these small barriers, keeping a much larger amount of liquid within the catchment area for the oil pick-up. Although this is not a fool-proof method against starvation, it is a much cheaper solution for most manufacturers instead of a full dry sump system which can require a whole load of reconfiguration within the engine bay.

Much like a cooling system, a true petrolhead really shouldn’t neglect the vital life supply for their engine that is the oil supply. An engine starved of oil gets very hot very quickly, along with wear on the moving parts dramatically increasing, potentially leading to catastrophic engine failure. So if you’re in the mood for a slightly convoluted but rewarding modification that you can reap the rewards from dynamically, a dry sump isn’t a bad shout.