12.32 Lubrication Systems - Engines

12.32.2 State the functions of an engine lubrication system.

The engine lubrication system performs several essential functions:

• Lubrication:
  Reduces friction between moving parts (e.g. pistons, crankshaft, camshaft), minimising wear and preventing damage
• Cooling:
  Carries heat away from engine components, helping to regulate temperature
• Cleaning:
  Removes and suspends contaminants such as dirt, metal particles, and carbon, keeping the engine clean
• Sealing:
  Provides a sealing effect between components (e.g. piston rings and cylinder walls), improving compression
• Corrosion protection:
  Coats internal surfaces to help prevent rust and corrosion

Summary:
The lubrication system reduces friction, removes heat, cleans, seals, and protects engine components, ensuring efficient operation and long engine life.

12.32.4 Explain the term viscosity.

Viscosity is a measure of a fluid’s resistance to flow.

In simple terms, it describes how thick or thin a fluid is:

• High viscosity: thick fluid, flows slowly (e.g. oil, honey)
• Low viscosity: thin fluid, flows easily (e.g. water, fuel)