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I've heard references to dry sumps, usually in reference to racing engines. But more recently I came across an article about a 'supercar' which stated that it had a dry sump.

What are the benefits of a dry sump?

Could a regular oiling arrangement be upgraded to one?

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Dry sump motorcycles sing the song of my people. – DucatiKiller Jan 19 at 0:21
up vote 19 down vote accepted

You Asked

What are the benefits of a dry sump?

Simply put a wet sump crankcase has oil sitting in the bottom of the crankcase.

It's affected by various forces as the car or motorcycle is driven. At times it is possible, during hard braking or cornering, that the oil pickup is not in oil, resulting in a low or no oil pressure condition that could temporarily leave the engine without good oil pressure for lubrication.

IMO this would be rare, even under hard driving, on the street.

By viewing the image below you can see how the oil sits at the bottom of the crankcase in a 'pool'.

Diagram of car engine showing oil location

A dry sump engine will have a pickup along the bottom of the crankcase that oil typically will fall into thus scavenging all excess oil. This oil is pumped into an oil tank where another pump will drive oil pressure into the ice.

This is primarily for race application and some motorcycles. Rotax has implemented this system with Aprilia. The BMW Dakar Edition on/off road motorcycles have this feature whereas the standard edition of the motorcycle does not.

A motorcyclist can ride wheelies for miles, a Baja Desert Racer can jump their truck and drive through long off-camber turns at speed without worrying about loss of oil pressure and engine damage.

Diagram showing operation of dry sump engine

Answer

Dry sump oil delivery ensures oil pressure to the engine in most all conditions and reduces risk regarding low oil pressure to the engine.

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2  
In addition, for race cars especially it means that the engine can sit lower as there's no sump to accommodate at the bottom of the engine. – RemarkLima Jan 19 at 19:45

An addition to the previous answers: A limiting factor in car construction is the engine height. Using a dry sump setup the engine gets smaller in height and can be located lower. This lowers the car's center of gravity resulting in a better track performance.

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Very good point – DucatiKiller Jan 18 at 23:53

Dry sump oiling systems are primarily used in racing situations. The main purpose is it will provide oil pressure under any type of hi-G maneuvers, to include cornering, braking, and acceleration.

A dry sump oiling system is made up of several parts. The reason why it is called a "dry sump" is because the sump, where in a normal engine is the reservoir for the oil pump to draw from, is kept relatively dry by a scavenge pump which is actually external of the engine. Here is what a typical dry sump system looks like (sans the hoses and reservoir):

enter image description here

The red part at the bottom is the pump. It is ran directly from the crankshaft via the belt. There are hoses which attach to the sump which scavenges the oil out of the pan (crankshaft area). The oil is then pumped into a reservoir where it sits until drawn upon by the pump (pressure side this time) to be shot back into the engine. Somewhere in there it goes through a filter.

Any car could possibly be retrofit for a dry sump ... most cars would never see any benefit from it. Some engines come with them, such as the LS7 used in the Corvette and Camaro Z28. Most of the supercars use them. In most cases the costs involved to put one on a vehicle which doesn't have an aftermarket for such a thing would never see a return in the cost to benefit ratio, so it just doesn't make sense. If the car which it might be going into is used for autocross or drifting or some such, putting one in may be of benefit. Getting one fit for a vehicle is not cheap, so make sure you have the deep pockets before going that route, especially when a regular wet sump will work just fine.

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Per Wikipedia. https://en.wikipedia.org/wiki/Dry_sump

A dry sump offers many advantages.[1] The most obvious are increased oil capacity afforded by the remote reservoir, and the capability to mount the engine lower in the vehicle because of the lower sump profile—lowering the overall center of gravity. The external reservoir can also be relocated to another part of the car to improve weight distribution. Increased oil capacity by using a larger external reservoir than would be practical in a wet-sump system cools the oil more and releases entrained gasses from ring blow-by and the action of the crankshaft. Furthermore, dry-sump designs are not susceptible to the oil movement problems from high cornering forces that wet sump systems can suffer. In a wet sump, the force of the vehicle cornering can force the oil to one side of the oil pan, possibly uncovering the oil pump pickup tube and causing a loss of oil pressure.

Given enough time & money anything is possible. A bolt on kit will probably not be available for most cars on the market.

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