Lecture Notes: How a Car Engine Works by Jake O'Neal

Introduction

• Speaker: Jake O'Neal, creator of Animagraffs
• Topic: Explanation of how a car engine works

Engine Mechanics

Single Piston and Four Stroke Cycle

• Piston Function: The powerhouse of the engine
• Four Stroke Cycle:
  1. Intake:
     • Piston descends
     • Air-fuel mixture is sucked into cylinder through intake port
     • Intake valves open
  2. Compression:
     • Piston ascends
     • All valves closed
     • Fuel and air mixture compressed
  3. Power Stroke:
     • Electrical spark ignites compressed mixture
     • Combustion forces piston down
     • Power transferred to crankshaft via connecting rod
  4. Exhaust:
     • Piston ascends again
     • Spent mixture pushed out through open exhaust valves and port

Connecting Multiple Pistons

• Firing Order: Pistons fire in order 1-3-4-2
• Camshafts: Specially shaped cams open valves in turn
• Crankshaft:
  • Translates piston power
  • Counterweights balance pistons for smooth revolutions
  • Revolutions per minute (RPM): Measures crankshaft rotations
• Engine Block & Cylinder Head:
  • Engine block holds crankshaft and cylinders
  • Cylinder head holds valves, ports, cams
• Flywheel & Transmission:
  • Flywheel connects to transmission and starter

Engine Configurations

• Common configurations include:
  • Four cylinders in a single row
  • Six cylinders in a V shape
  • Eight cylinders

Supporting Systems

Air Intake

• Air filter leads to intake manifold
• Mixture of air and fuel enters cylinders via intake ports

Fuel System

• Fuel pump transports gas from tank to engine
• Fuel injectors spray gas precisely into intake port

Cooling System

• Coolant:
  • Antifreeze circulates to keep engine cool
  • Channels around cylinders and through heads
• Radiator:
  • Network of tubes and fins cools the liquid
  • Water pump circulates coolant
  • Thermostat regulates temperature

Electrical System

• Spark Plugs: Ignite fuel-air mixture
• Coil Pack & ECM:
  • Coil pack delivers current to spark plugs
  • ECM controls spark timing, valve timing, air-fuel ratio
• Alternator: Converts mechanical to electrical energy
• Battery: Powers the starter

Oil System

• Motor Oil:
  • Lubricates, cleans, prevents corrosion
  • Seals and cools engine parts
• Oil Flow:
  • Rings on piston head keep oil out of combustion
  • Galleries carry oil through the engine
  • Oil pan and pump manage oil circulation
  • Oil filter cleans contaminants

Exhaust System

• Exhaust Manifold: Combines gases from cylinders
• Catalytic Converter: Captures toxic chemicals
• Muffler: Reduces noise

Conclusion

• Overview of the full functioning engine with its systems
• All systems contribute to engine performance and efficiency