Lubrication System

Question 1

What is the main function of the lubrication system?

Answer 1

Supplies oil to moving parts of the engine to reduce friction and minimise wear

Question 2

How does the pressure relief valve operate?

Answer 2

Controls limit pressure
Opens when the safe permissible pressure is exceeded

Question 3

What is the function of the oil filter?

Answer 3

Removes impurities (metal particles and carbon residue) from the oil

Question 4

How to improve lubrication and cooling of engine?

Answer 4

• Extra oil passages in connecting rod
• Oil holes at the bottom of the connecting rods
• Oil jet nozzles in cylinder blocks

Question 5

What does the SAE number tell about the oil’s viscosity?

Answer 5

Shows how easy the oil flows at different temperatures

E.g. 5W - 20

5 represents viscosity at low temperatures, W stands for winter. A lower number means oil flows more easily at low temperatures

20 represents viscosity at high temperatures. A high number means oil flows less easily at high temperatures.

Question 6

What causes poor lubrication?

Answer 6

• Oil contamination:
  Foreign objects enter the system due to poor sealing, leaks from pipelines and storage tanks and engine wear
• Moisture contamination:
  Occurs through condensation in cold or humid conditions

Question 7

How does a pressure system deliver lubricant?

Answer 7

• A pump takes oil from sump and distributes it to moving parts under pressure through pipes. Excess oil drains off and return to sump
• Types are gear and rotary

Question 8

How does a splash system deliver lubricant?

Answer 8

Moving parts rotates and dip into the oil reservoir and splash it upwards creating a mist of lubricant to coat other parts