Engine Fundamentals

Definition of Engine

• An engine is a machine designed to convert one form of energy into mechanical energy.
• Heat engines burn fuel to create heat, which is then used to do work.

Types of Engines

1. Internal Combustion Engine (ICE)
   • Burns fuel inside the engine cylinder.
2. External Combustion Engine (ECE)
   • Burns fuel outside the cylinder.

Importance

• The engine is considered the heart of an automobile.

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Main Parts of an Internal Combustion Engine

1. Cylinder Block

   • Basic framework of the engine.
   • Consists of:
     • Cylinder for piston movement.
     • Ports for valves.
     • Passages for cooling water.
   • Made of gray cast iron or aluminum.

2. Cylinder Head

   • Joins with the cylinder block.
   • Contains:
     • Combustion chamber.
     • Valve guides and seats.
     • Cooling passages.
   • Types:
     • Loop flow type.
     • Offset cross flow type.
     • Inline cross flow type.

3. Crankcase

   • Lower part of the cylinder block.
   • Supports crankshaft and maintains alignment.

4. Oil Pan

   • Bottom half of the crankcase.
   • Stores and circulates lubricating oil.
   • Contains a drain plug for oil replacement.

5. Manifolds

   • Set of pipes for air-fuel mixture and exhaust gases.
   • Typically made of cast iron.

6. Gaskets

   • Provide tight joints between surfaces (e.g., cylinder head and block).
   • Materials: cork, asbestos, rubber.

7. Cylinder Liners

   • Prevent cylinder wear and can be replaced.
   • Types:
     • Dry liners.
     • Wet liners.

8. Pistons

   • Convert pressure energy into mechanical power.
   • Move up and down within the cylinder.
   • Made of cast iron or aluminum alloy.
   • Piston clearance allows lubricant space.

9. Piston Rings

   • Maintain a seal between piston and cylinder wall.
   • Types:
     • Compression rings.
     • Oil control rings.

10. Connecting Rod

    • Connects piston to crankshaft.
    • Converts reciprocating motion to rotary motion.

11. Piston Pin

    • Also known as wrist pin; connects the rod and piston.
    • Types:
      • Set screw type.
      • Semi-floating type.
      • Fully floating type.

12. Crankshaft

    • Converts piston motion into rotational motion.
    • Made of heat-treated alloy steel.

13. Camshaft

    • Controls valve openings.
    • Driven by the crankshaft with half the speed.
    • Types of drive mechanisms:
      • Gear drive.
      • Chain drive.
      • Belt drive.

14. Flywheel

    • Attaches to the crankshaft's rear end.
    • Helps maintain constant speed.

15. Engine Valves

    • Control air-fuel mixture and exhaust gases.
    • Fit on valve seats in a closed position.

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Conclusion

• Understanding the parts and functions of an internal combustion engine is vital for automotive knowledge.
• For further study, check the link in the description for a downloadable PDF.