Piston
Moves inside the cylinder and transfers combustion force to the crankshaft through the connecting rod.
4-Cylinder Inline EngineINTERACTIVE 3D
Every component has a purpose. Discover how they work together.
FROM FUEL TO MOTION
One cycle. Four strokes.
Two crankshaft revolutions. One power stroke per cylinder.
FOUR-STROKE GUIDE
ILLUSTRATIVE SECTION
INTAKE STROKE
Let the engine breathe.
The intake valve opens as the piston travels down. Fresh air and fuel enter the cylinder, ready for the next stroke.
Intake open · Exhaust closed720°in a complete cycle
4cylinders working together
Understand the engine, step by step
Follow the path from combustion to motion, learn the four-stroke cycle, and identify the parts in the model.
Car engine parts and their functions
Piston Ring
Seals combustion pressure, controls oil on the cylinder wall, and conducts heat away from the piston.
Piston Pin
A hollow steel pin forms the pivot between the piston and the connecting rod.
Connecting Rod
Connects the piston to the crankshaft, converting linear travel into rotation.
Crankshaft
Offset crank throws turn the force from the pistons into useful rotary motion.
Cylinder Block
The main engine structure supports the cylinders, crankshaft bearings and passages for coolant and oil.
Cylinder
A precision bore guides the piston and provides a durable sliding and sealing surface.
Cylinder Head
Closes the cylinders and carries the valves, spark plugs and combustion-chamber surfaces.
Intake Valve
Opens during intake to admit fresh air and fuel, then closes to seal the combustion chamber.
Exhaust Valve
Opens during the exhaust stroke so the rising piston can expel burned gases.
Camshaft
Precisely timed lobes open the valves. In a four-stroke engine the cams turn at half crankshaft speed.
Timing Chain
Keeps the crankshaft and camshafts in phase, coordinating valve opening with piston travel.
Spark Plug
An electric arc ignites the compressed air-fuel mixture near the end of compression.
Flywheel
Stores rotational energy and smooths the pulses delivered by individual combustion events.
Oil Pump
Pressurizes and circulates oil to lubricate bearings and other moving surfaces.
Water Pump
Circulates coolant through the engine and radiator to carry away heat.
Alternator
Converts mechanical rotation into electrical energy for vehicle systems and battery charging.
Valve Cover
Encloses the valvetrain and helps retain the oil used to lubricate the camshafts.
Intake Manifold
Distributes incoming air to the four intake ports. Curved runners guide flow to each cylinder.
Exhaust Manifold
Collects hot exhaust gas from each cylinder into a common outlet.
Oil Pan
Collects returning engine oil in a sump beneath the crankshaft.
Main Bearings
Support the crankshaft on a thin film of pressurized oil, reducing friction and wear.
Valve Springs
Close the valves after each cam lobe passes and maintain contact through the valvetrain.
Valve Followers
Transmit the lift of the cam lobes to the valve stems.
Throttle Body
Regulates the amount of air admitted to the intake manifold.
Air Intake
Routes filtered air toward the throttle and intake manifold.
Fuel Rail
Supplies pressurized fuel to the injectors serving the cylinders.
Starter Motor
Turns the engine during starting until combustion can sustain its rotation.
Oil Filter
Removes particles from circulating engine oil to protect moving surfaces.
Crank Pulley
Transfers crankshaft rotation to the accessory drive.