Splash Lubrication System in IC Engines | Diagram and Explanation.

The splash lubrication system is the simplest and most cost-efficient lubrication system used in automobile vehicles. In this article, I will explain the splash lubrication system. 

Splash Lubrication System

Splash Lubrication System

In this system of lubrication, the lubricating oil is in an oil sump. A scoop or dipper is made in the lowest part of the connecting rod. When the engine runs, the dipper dips in the oil once in every revolution of the crankshaft ad causes the oil to splash on the cylinder walls.
This action affects the lubrication of the engine walls, piston rings, crankshaft bearings, and big-end bearings.
The splash system mostly works in connection with the pressure system in an engine, with some parts being lubricated by the splash system and others by the pressure system(Semi-pressure lubrication system). 
[Note- No oil pump was used in the Splash Lubrication System. In the Semi-pressure lubrication system, the splash system works with the oil pump. ]

Splash Lubrication System Line Diagram

Splash Lubrication System Line Diagram.


Working on Splash Lubrication System

In the splash lubrication system, there was a separate space for the oil sump used for storing the engine oil for lubrication. After the Petroil Lubrication System, the problems increased inside the engine and the emissions also happened. 
The splash lubrication system is the better version of it. Let’s talk about how this system works-

1. OIl sump or oil pan

The oil sump, also known as the oil pan, is a reservoir located at the bottom of the engine. It holds the engine’s lubricating oil, which is essential for ensuring proper lubrication of the moving parts.

2. Engine Crankshaft

The crankshaft is a vital and important item in this system. The scoop, which is important for this lubrication system is attached to the end of the crankshaft. As the pistons move up and down in their cylinders, the crankshaft transforms this linear motion into circular motion. It is connected to the connecting rods, which, in turn, are linked to the pistons.

3. Oil level

The engine oil sump is designed in a manner that it can keep a perfect oil level to provide the engine lubrication perfectly. The oil and the dipping of the scoop affect the whole lubrication system. 

4. Oil Pickup Scoop

The oil pickup scoop is a small scoop attached to the bottom of the engine’s crankshaft into the oil sump. Its purpose is to draw oil from the sump and deliver it to the engine’s moving parts for lubrication.

5. Oil Distribution

In this type of lubrication system, the scoop dips into the oil sump and splashes under the piston area of the cylinder walls. The spinning motion causes the oil to be flung or “splashed” onto various engine components, including the crankshaft, connecting rods, pistons, cylinder walls, and camshaft. The oil forms a thin film on these parts, providing lubrication to reduce friction and prevent metal-to-metal contact.
The oil not only protects the engine parts from rubbing with each other, but it also dissipates the heat and works as a cooling media also. As the oil comes into contact with the hot engine parts, it absorbs and carries away some of the heat, contributing to engine cooling.

Advantages of Splash Lubrication System

The splash lubrication system has its own advantages of co-efficient of engine lubrication and heat dissipation. The simple design and value for money make it perfect for small machinery designs. Some of the other advantages are- 
  1. This system is suitable for budget-friendly applications and smaller engines.
  2. The simple design contributes to their reliability and ease of maintenance.
  3. It is easy to maintain. 
  4. This lubrication system can self-rotate based on the engine RPM. So there is no need for extra fitment to operate this system. 
  5. The oil, when splashed onto engine components, helps in dissipating heat generated during engine operation, which contributes to keeping the engine within its optimal temperature range.
  6. This process uses gravitational force to come back from the splash parts.
  7. In certain applications where space and weight are critical factors, splash lubrication offers a lightweight and compact lubrication solution.

Disadvantages of Splash Lubrication System

If there are advantages then there are disadvantages also. If the system is too efficient then why is this system not in the marker then? So the disadvantages are- 
  1. This system has limited lubrication at high speed. 
  2. As the engine’s RPM increases, the oil may not have sufficient time to spread and adequately lubricate all the moving parts. This can lead to increased friction and wear on critical components.
  3. The oil distribution relies on the motor running condition so efficient supply was lacking in this system.
  4. Since the oil in a splash lubrication system is not actively filtered or pressurized, it can become contaminated with debris, dirt, and metal particles.
  5. A splash lubrication system is generally for the lower application vehicles. In heavy-load vehicles, this system is not perfect. 
  6. The lack of filtration in splash lubrication can result in higher emissions and environmental pollution if contaminants from the oil get released into the atmosphere.
Due to these limitations, this system was founded on lower-speed engines. 


Overall, the splash lubrication system is a simple, cost-effective method for providing lubrication to the moving parts of an engine.
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