4 stroke engine diagram

Let us first understand some basic terms associated with a 4-stroke engine. Top dead center (TDC): It is the extreme position of the piston at the head end of the cylinder. At TDC the crank angle is 0* Bottom dead center (BDC): The extreme position of the piston at the crank end side. At BDC, the crank angle is a 180* Cylinder bore: It is the internal diameter of the cylinder. Stroke: It is the distance through which the piston moves in the cylinder during 1 stroke. Parts of 4-Stroke engine’s: A Four-stroke engine consist of the following parts: • Cylinder: It is the heart of the engine. The piston reciprocates in the cylinder. • Cylinder head: It is the top cover of the cylinder, towards TDC, which is called the cylinder head. • Piston: It is the reciprocating member of the engine. It reciprocates in the cylinder. • Piston rings: Two or three piston rings are provided on the piston. It seals the gap between the cylinder liner and piston. • Crank: It is a rotating member. It makes a circular motion inside the crankcase. • Crankcase: It is the housing of crank and other engine parts. It is also used as the sump of lubricating oil. • Connecting rod: It is used to convert the reciprocating motion of the piston to rotary motion of the crankshaft. • Crankshaft: It is the rotating member, which connects the crank. • Cooling fins or Water jackets: It is used for cooling purposes. • Cam and Camshaft: It is used to allow the opening and closing of the Inlet and Exhaust valve and al...

That’s nothing to be ashamed of either. The fact of the matter is that most people only rely on 4-stroke engines. And even that is changing as electric cars, motorcycles, and yard tools become more prominent in daily life. But, if you’re going to get into anything engine-related, you’re going to need to know the difference. Don’t worry, The Drive is on the case! First and foremost, 2-stroke and 4-stroke are terms that refer to the length of the engine cycle. To better understand what these terms mean, we need to start by clearing your mind. Get rid of everything you know about piston-driven engines aside from the fact that you have a piston continuously traveling up and down within the combustion chamber. Visualize that piston moving up and down. The power driving this motion comes from the ignition or combustion of the mixture, which sends the piston downward with tremendous force. Ignition is the primary goal, but fuel and air must first enter the chamber for that to happen. Then it must be compressed to maximize the amount of energy that’ll come from the burn. Once compressed, ignition occurs. But before the cycle can begin again, the exhaust from the spent mixture must exit the chamber. The term “stroke” comes from the motion of the piston throughout the engine cycle. The corresponding number refers to the number of times the piston needs to travel within the chamber to complete all functions. Simply put, 4-strokes accomplish these goals with four strokes, while 2-stro...

Most of the vehicles that rush on the road are powered by four-stroke IC engines. Based on the working cycle these are further classified as petrol engines and diesel engines. We notice four stroke petrol engines in light or medium-duty vehicles like motorcycles, cars, ATVs, etc. In this detailed article, we will discuss four stroke petrol engines. What is Four stroke petrol engine? The four stroke petrol engine is an IC engine that works on a petrol cycle and completes a single power cycle within four strokes of the piston or two revolutions of the crankshaft. The term “four-stroke” indicates the engine in which a single working cycle is completed within four strokes of the piston (suction, compression, expansion, exhaust) while “Petrol” indicates the engine that works on a petrol cycle (Otto cycle). As these engines use spark plugs for the combustion of the air-fuel mixture, these are also referred to as 4-stroke spark ignition (SI) engines. It runs on the fuels like gasoline, CNG, methanol, LNG, etc. These engines are generally lighter and smaller in size than the four-stroke diesel engines as it uses a lower compression ratio (8 to 12) in comparison with 4 stroke diesel engines (14 to 24). Thus these engines are used to run low to medium-duty automobiles. The four stroke petrol engine works on the principle of the otto cycle. The cycle was invented by the German engineer Nicolaus Otto and mainly consists of two adiabatic and two isochoric processes. It comprises the fo...

Most internal combustion engines work on one of two principles of operation: a two-stroke cycle or a four-stroke cycle. Four-stroke engines are the predominant type seen in general aviation and form the topic of this post. Piston Engine Cycles Piston engines are classified according to the number of distinct steps that the engine performs in one complete engine cycle. Two-stroke engines complete a cycle in one revolution of the crankshaft with two movements; an up and down stroke of the piston which incorporates intake, compression, combustion and exhaust. Two stroke engines are common on microlights and some smaller ultralight aircraft, as these engines have a lower part count making them simpler to operate and cheaper to procure and maintain. Four-stroke engines are the most common engine type in use in the general aviation industry and it is this engine type that we will study further. A four-stroke engine takes two crankshaft revolutions to complete one engine cycle with the piston moving through 180° to complete each step in the cycle. A four-stroke cycle includes an intake and compression step (one crankshaft revolution) and a power and exhaust step (one crankshaft revolution). Cycle Nomenclature There are a number of definitions that should be well understood before continuing with the details of the four-stroke cycle. Refer to the image below and the definitions underneath the image. Figure 1: The bore and stroke of a piston moving in a cylinder Top Dead Center (TD...

In order to power your equipment, the overhead valve engine completes a repeating 4-step process detailed below. Element that Allow Internal Combustion Engines to Run • Air • Fuel • Compression • Spark Step 1: Intake Stroke Air and fuel enter the small engine through the carburetor. It’s the job of the carburetor to supply a mixture of air and fuel that will allow for proper combustion. During the intake stroke, the intake valve between the carburetor and combustion chamber opens. This allows atmospheric pressure to force the air-fuel mixture into the cylinder bore as the piston moves downward. >> Having performance problems? Find out Step 2: Compression Stroke Just after the piston moves to the bottom of its travel (bottom dead center), the cylinder bore contains the maximum air-fuel mixture possible. The intake valve closes and the piston returns back up the cylinder bore. This is called the compression stroke of the 4-stroke engine process. The air-fuel mixture is compressed between the piston and cylinder head. Step 3: Power Stroke When the piston reaches the top of its travel (top dead center), it will be at its optimum point to ignite the fuel to get maximize power to your outdoor power equipment. A very high voltage is created in the ignition coil. The power stroke. Step 4: Exhaust Stroke When the piston reaches bottom dead center again, the exhaust valve opens. As the piston travels back up the cylinder bore, it forces the spent combustion gases through the exhaust...

What is Four stroke diesel engine? • Four stroke diesel engine is also known as the compressed ignition (CI) engine since in this kind of engine the combustion occurs due to the compressing a air more than fuel self-ignition temperature. • The compression ratio of this engine is higher as compared to SI engine and it not uses the spark plug. • This engine works on the • In this type of engine the diesel is used as the fuel. • The four strokes in this engine are suction, compression, power as well as exhaust. At the start, when the piston moves from TDC to BDC, from [ When the piston moves from TDC to BDC, the piston creates a vacuum inside the cylinder. Hence due to the pressure difference between intake manifold and cylinder, air enters into the cylinder. ] During this suction stroke, the inlet valve is open and at the end of the suction stroke inlet valve closes. During Compression, both valves (Inlet & Exhaust) are closed. After the compression of air, the fuel injector sprays the fuel inside the cylinder, hence fuel gets ignited (catch fire). Therefore Combustion starts, high-pressure gases expand (spread) inside the cylinder and push the piston downwards ( towards BDC). During expansion, both valves (Inlet & Exhaust) are closed. Power Stroke. After expansion stroke, the piston moves from BDC to TDC. During this movement of the piston (BDC to TDC), the Burnt During this exhaust stroke, only the exhaust valve is open and at the end of this stroke, exhaust valve closes a...