Four stroke si engine diagram

Theory and Design of Automotive Engines By B Dinesh Prabhu, Assistant Professor, P E S College of Engineering, Mandya, KARNATAKA 1 CHAPTER 2 FOUR-STROKE CYCLE S-I ENGINE - PRINCIPLE OF OPERATION Fig: cross section of a SI Engine In Four-stroke cycle engine, the cycle of operation is completed in four-strokes of the piston or two revolutions of the crankshaft. Each stroke consists of 180°, of crankshaft rotation and hence a cycle consists of 720°of crankshaft rotation. The series of operations of an ideal four-stroke. SI engine are as follows (see Fig.2.1 & 2.2) 1. Suction stroke Suction stroke 0-1 starts when the piston is at top dead centre and about to move downwards. The inlet valve is open at this time and the exhaust valve is closed. Due to the suction created by the motion of the piston towards bottom dead centre, the charge consisting of fresh air mixed with the fuel is drawn into the cylinder. At the end of the suction stroke the inlet valve closes. 2. Compression stroke. The fresh charge taken into the cylinder during suction stroke is compressed by the return stroke of the piston 1-2. During this stroke both inlet and exhaust valves remain closed. The air which occupied the whole cylinder volume is now compressed into clearance volume. Just before the end of the compression stroke the mixture is ignited with the help of an electric spark between the electrodes of the spark plug located in combustion chamber wall. Burning takes place when the piston is almost at t...

four-stroke cycle, also called Otto cycle or four-cycle engine, principle by which most modern A disadvantage of the four-stroke cycle is that only half as many power strokes are completed as in the two-stroke cycle and only half as much power can be expected from an engine of a given size at a given operating speed. The four-stroke cycle, however, provides more positive clearing out of exhaust gases (scavenging) and reloading of the cylinders, reducing the loss of fresh charge to the exhaust.

Figure 1. 4-stroke internal combustion engine. 1:fuel injection, 2:ignition, 3:expansion(work is done), 4:exhaust. The four-stroke engine is the most common types of • Intake stroke: The piston moves downward to the bottom, this increases the • Compression stroke: The intake valve is closed, and the piston moves up the chamber to the top. This compresses the fuel-air mixture. At the end of this stroke, a spark plug provides the compressed fuel with the activation energy required to begin combustion. • Power Stroke: As the fuel reaches the end of it’s combustion, the heat released from combusting hydrocarbons increases the • Exhaust stroke: As the piston reaches the bottom, the exhaust valve opens. The remaining exhaust gas is pushed out by the piston as it moves back upwards. The The Otto Cycle The The following describes what occurs during each step on the PV diagram, in which the combustion of the working Real cycle-step 0 to 1 (ideal cycle-green line): Referred to as the intake phase, the piston is drawn down to the bottom to allow the volume in the chamber to increase so it can "intake" a fuel-air mixture. In terms of thermodynamics, this is referred to as an Process 1 to 2: During this phase the piston will be drawn up, so it can compress the fuel-air mixture that entered the chamber. The compression causes the mixture to increase slightly in pressure and Process 2 to 3: This is where Process 3 to 4: The thermal energy in the chamber as a result of combustion is used ...

• العربية • Català • Čeština • Dansk • Deutsch • Español • Esperanto • فارسی • Français • Galego • 한국어 • Bahasa Indonesia • Italiano • Magyar • മലയാളം • Nederlands • नेपाली • 日本語 • Norsk nynorsk • Polski • Português • Русский • Sardu • Slovenčina • کوردی • தமிழ் • Türkçe • Українська • Tiếng Việt • 中文 c = The idealized diagrams of a four-stroke Otto cycle A and colored green) stroke is performed by an B and colored orange) stroke. Through the combustion of fuel, heat is added in a constant volume ( C and colored red) stroke. The cycle is closed by the exhaust (letter D and colored blue) stroke, characterized by isochoric cooling and isobaric compression processes. An Otto cycle is an idealized The Otto cycle is a description of what happens to a gas as it is subjected to changes of pressure, temperature, volume, addition of heat, and removal of heat. The gas that is subjected to those changes is called the system. The system, in this case, is defined to be the fluid (gas) within the cylinder. By describing the changes that take place within the system, it will also describe in inverse, the system's effect on the environment. In the case of the Otto cycle, the effect will be to produce enough net work from the system so as to propel an automobile and its occupants in the environment. The Otto cycle is constructed from: Top and bottom of the loop: a pair of quasi-parallel and Left and right sides of the loop: a pair of parallel The isentropic process of compression or expan...

As we know, a spark-ignition engine is an internal combustion engine which is also called a Petrol engine. In the S-I engine, the combustion process of the air-fuel mixture is ignited by a spark plug. S-I engine is an Otto cycle engine. The working cycle of the SI engine may be two-stroke or four-stroke. Its thermal efficiency is less as compared to the CI engine. Four-Stroke SI Engine. • Suction • Compression • V=C(Heat addition) • Expansion • V=C(Heat rejection) • Exhaust Four Stroke SI Engine with P-V diagram SUCTION STROKE:- It is also called an induction or intake stroke. The piston moves from TDC(top dead center) to BDC(bottom dead center) and the inlet valve must be open and the exhaust valve is closed. The fresh air-fuel mixture enters from the inlet valve because the piston is moving down as air is being sucked in by downward motion against the piston. Suction Stroke COMPRESSION STROKE:- During the compression stroke, the compression of charge takes place when the piston moves from BDC to TDC. SO, in this stroke piston compresses the fresh air-fuel mixture in preparation for ignition. Both the intake and exhaust valve remain closed during this stage. The charge which is occupied by the whole cylinder volume is now compressed up to the clearance volume. Just before the completion of the compression stroke, a spark is produced by the spark plug. Fuel is ignited and the combustion takes place when the piston is at TDC. Compression Stroke CONSTANT VOLUME HEAT ADDITION...

Four-stroke-engine is the commonly uses type of engine that many cars have. There are reason why many cars use 4-stroke-engine, basically four stroke engine has lower fuel consumption. That’s make cars more economic, moreover this type of engine has better emission than two stroke engine. Today, we’ll learn about the diagram of 4 stroke engine cycle. If you have a question, how four stroke engine work ? in this article you will find the answer. 4 Stroke Engine Working Principle As the name, this engine have 4 steps in a cycle. • Suction/intake stroke • Compression stroke • Combustion stroke • Exhaust stroke Before we discuss about working principle, you need to understand main part of this engine. At least, there are 4 main part ; • Cylinder block, tubular part that uses for piston movement. • Head cylinder, closed top cylinder that use as combustion chamber and the housing part of another engine part (ie : spark plug, and valve mechanism). • Piston, silindrical part that move upwad and downward. The movement of piston will change the volume inside the combustion chamber, that’s the main idea of 4 stroke engine working. • Valve mechanism, this valve have a role as door to enter the air inside the combustion chamber and to take out exhaust gases to the mufler. The valve, operated by a mechanism that bound to the crank shaft of engine. After you understand the main part, lets discuss the main menu ; 1. Intake stroke Intake stroke is a process where gas (a mixture of air and ...