Car Engine Overview

Overview

This lecture explains how a car engine works, detailing its main parts, the combustion process, different engine types, and basic maintenance.

Most cars use an internal combustion engine, which creates power through small explosions of fuel and air ignited by a spark.
The first operational gasoline combustion engine was invented by Etienne Lenoir in 1859.
The basic cycle: air enters through an intake valve, mixes with fuel in a cylinder, and is ignited by a spark plug to produce power.

The engine block houses the cylinders and is the main structure of the engine.
Valves regulate the flow of air and exhaust; each cylinder typically has an intake and exhaust valve.
Pistons move up and down inside the cylinders and drive the combustion cycle.
The crankshaft connects to pistons via rods and controls their motion.
Spark plugs at the top of cylinders ignite the air-fuel mixture.
The timing belt links the crankshaft and camshaft, coordinating engine timing.
The camshaft manages the opening and closing of valves.

Intake Stroke: piston moves down, intake valve opens, and air enters the cylinder.
Compression Stroke: piston moves up, compressing air and fuel.
Combustion/Power Stroke: spark plug ignites mixture, pushing piston down.
Exhaust Stroke: piston moves up, exhaust valve opens, and gases are expelled.

Turning the key activates the starter motor, which powers the starter solenoid.
The distributor sends electrical current to spark plugs via ignition wires, starting combustion.

Inline engines have cylinders arranged in a straight line; common in sedans and hatchbacks.
V6 and V8 engines have cylinders arranged in a V shape for more power.
HEMI engines use hemispherical combustion chambers for increased power.
Two-stroke engines complete a power cycle in two strokes; common in small machines.
Diesel engines use diesel fuel and compress air to ignite fuel—no spark plugs required.

Diesel engines run on diesel fuel and initiate combustion through high compression and heat instead of spark plugs.
These engines generate more torque and are typically more fuel efficient.

Regularly replace engine oil, coolant, and air filters to prevent friction and overheating.
Routine maintenance improves engine performance and longevity.

Internal Combustion Engine — Engine powered by igniting fuel and air inside cylinders.
Cylinder — Chamber where fuel-air mixture ignites and power is produced.
Valve — Device regulating airflow in and out of cylinders.
Piston — Moving part inside the cylinder driving the engine cycle.
Crankshaft — Converts piston motion into rotational force.
Spark Plug — Part that ignites fuel-air mixture.
Timing Belt — Synchronizes engine parts for proper operation.
Camshaft — Controls the valves' operation.
HEMI — Hemispherical combustion chamber design for enhanced power.
Diesel Engine — Uses diesel fuel and high compression for ignition.