Describe the working principle of the four stroke cycle.
(10)
The Four-Stroke Cycle
A four-stroke cycle engine is a type of internal combustion engine that completes one power cycle in four distinct piston strokes. Each stroke represents the full travel of the piston, either up or down within the cylinder. Let’s break down the four strokes:
1. Four-stroke cycle | Definition, History, & Facts – Britannica
2. Four-stroke engine – Wikipedia
1. Intake Stroke
- Piston moves: Downward 1. 4-Stroke Engines: What Are They and How Do They Work? – Universal Technical Institute www.uti.edu
- Valves: Intake valve open, exhaust valve closed 1. Four-stroke engine – Wikipedia en.wikipedia.org
- Process: As the piston moves downward, a vacuum is created in the cylinder. This vacuum pulls in an air-fuel mixture through the open intake valve. 1. How an Engine Piston Works – Ferber’s Tire & Auto Service ferberstireandauto.com2. 4-Stroke Engines: What Are They and How Do They Work? – Universal Technical Institute www.uti.edu
2. Compression Stroke
- Piston moves: Upward
- Valves: Both valves closed 1. Both the valves of a petrol engine are closed and piston moving towards spark plug during.Expansion strokeIntake strokeExhaust strokeCompression stroke www.toppr.com
- Process: The air-fuel mixture trapped in the cylinder is compressed by the upward-moving piston. This compression increases the temperature and pressure of the mixture. 1. Previous Page www.chm.bris.ac.uk2. Compression and Expansion – Glenn Research Center | NASA www1.grc.nasa.gov
3. Power Stroke
- Piston moves: Downward
- Valves: Both valves closed
- Process: The compressed air-fuel mixture is ignited by a spark plug. The resulting explosion forces the piston downward, generating power that is transferred to the crankshaft. 1. The compressed air and petroleum mixture is ignited by the spark produced by the spark plug. This is known as . – BYJU’S byjus.com2. Ask Andrew: Suck Squeeze Bang Blow – The case for compression – Dev Canadian Boating canadianboating.ca
4. Exhaust Stroke
- Piston moves: Upward
- Valves: Exhaust valve open, intake valve closed
- Process: The piston moves upward, forcing the spent exhaust gases out of the cylinder through the open exhaust valve. 1. Engine Mechanical Operation – Exhaust Stroke www.grc.nasa.gov
To summarize:
- The intake and compression strokes prepare the engine for combustion. 1. Four-stroke engine – Wikipedia en.wikipedia.org
- The power stroke produces the energy to drive the engine. 1. Internal combustion engine – Wikipedia en.wikipedia.org
- The exhaust stroke removes the waste products. 1. Engine Mechanical Operation – Exhaust Stroke www.grc.nasa.gov
This cycle repeats continuously, with each complete cycle producing one power stroke.
1. Four-stroke principle — Het Thermotechnisch Instituut – Departement Werktuigkunde – KU Leuven
Opens in a new windowwww.britannica.com
fourstroke cycle