How a Car Engine Works

Introduction

• Presented by Jake O'Neal, creator of Animagraffs
• Explanation of a car engine's functionality

The Four-Stroke Cycle

• Intake: Piston descends, sucking in air-fuel mixture through intake port with both intake valves open
• Compression: Piston ascends with all valves closed, compressing the air-fuel mixture for combustion
• Power Stroke: Spark ignites the compressed mixture, combustion forces piston down, transferring power to the crankshaft
• Exhaust: Piston ascends again, pushing spent mixture out through exhaust valves and port

Connecting Multiple Pistons

• Pistons fire in turns for smooth power delivery
• Example firing order: 1-3-4-2
• Camshafts with cams push spring-loaded valves open in turn
• Cam gears and timing belt/chain link to crankshaft
• Crankshaft translates power from pistons, with counterweights for smooth revolutions
• RPM (revolutions per minute): counts crankshaft spins per minute
• Engine block holds crankshaft and cylinders
• Cylinder head holds valves, ports, cams, etc.
• Geared flywheel connects crankshaft to transmission and starter

Engine Configurations

• Various configurations, e.g., four cylinders in a row, six cylinders in a V shape, etc.
• Basic engine parts remain the same

Supporting Systems

Air Intake

• Air enters through air filter
• Mixes with fuel in intake manifold
• Sucked into cylinders via intake ports

Fuel System

• Fuel pump carries gas from tank, through fuel filter, to engine
• Fuel injectors emit timed gas sprays into intake port

Cooling System

• Engines get very hot, require cooling
• Coolant (anti-freeze) circulates around cylinders and through the radiator
• Radiator has tubes and fins, cooled by air
• Water pump keeps coolant flowing
• Thermostat regulates coolant temperature

Electrical System

• Spark plug ignites air-fuel mixture
• Coil pack delivers current to spark plugs, managed by ECM (engine control module)
• ECM controls spark timing, valve timing, air-fuel ratio
• Alternator generates electricity for battery and electrical systems
• Battery powers starter for engine startup

Oil System

• Motor oil lubricates and cools the engine, prevents corrosion, improves sealing
• Oil galleries carry oil to engine parts
• Oil pump keeps oil pressurized
• Oil pan stores oil when not circulating
• Oil filter cleans oil of contaminants

Exhaust System

• Exhaust manifold collects gases from cylinders
• Catalytic converter captures toxic chemicals
• Muffler reduces exhaust noise

Full Engine Model

• Complete functioning engine with all discussed systems integrated