Draw the neat sketch of overhead valve operating mechanism and explain its working.

Draw the neat sketch of overhead valve operating mechanism and explain its working.
by

1 Answer

Answer :

Overhead valve mechanism: Figure shows the valve mechanism to operate the valve when it is in the cylinder head (in I and F head design). This type of mechanism requires two additional moving parts the push rod and rocker arm. As the cam rotates, it lifts the valve- tappet or the lifter which actuates the push rod. The push rod rotates the rocker arm about a shaft- the rocker –arm shaft, or a ball joint in some designs to cause one end to push down on the valve stem to open the valve, thus connecting the valve port with the combustion chamber.

image 

Fig. Overhead valve mechanism

OR 

Overhead valve mechanism : Working: As the camshaft rotates, each off-center (eccentric) cam lobe pushes against a lifter or tappet. The upward motion of the lifter transfers through the push rod to the rocker arm. This upward motion changes to downward motion as the rocker arm pivots. The downward motion opens the valve. As the camshaft continues to rotate, the lobe passes by the lifter and allows the valve to close. A spring (attached to the valve) returns the valve to its seated position. 

image  

by

Related questions

Explain working of over head valve mechanism with neat sketch.

Description : Explain working of over head valve mechanism with neat sketch.

Last Answer : Overhead valve mechanism: Figure shows the valve mechanism to operate the valve when it is in the cylinder head (in I and F head design). This type of mechanism requires two additional moving parts the ... to close. A spring (attached to the valve) returns the valve to its seated position.  

Explain the working of overhead valve arrangement with sketch.

Description : Explain the working of overhead valve arrangement with sketch.

Last Answer : Overhead Valve Arrangement: Figure shows the valve mechanism to operate the valve when it is in the cylinder head (in I and F head design). This type of mechanism requires two additional ... on the valve stem to open the valve, thus connecting the valve port with the combustion chamber.

Draw neat sketch of valve timing diagram for 4-stroke petrol engine & label it.

Description : Draw neat sketch of valve timing diagram for 4-stroke petrol engine & label it.

Last Answer : Figure: Valve timing diagram of 4 stroke SI engine  

Describe push rod overhead valve operating mechanism with neat sketch.

Description : Describe push rod overhead valve operating mechanism with neat sketch.

Last Answer : Push rod Overhead valve operating mechanism (OHV 4 -S engine): An overhead valve engine (OHV engine) is an engine in which the valves are placed over the cylinder head. The camshaft drive-chain ... . Overhead valve arrangement makes the engine slightly shorter than overhead camshaft.   OR  

Statement: Valve Cooling is necessary in some I. C. Engine. Justify the statement by giving reasons and explain its working with sketch.

Description : Statement: Valve Cooling is necessary in some I. C. Engine. Justify the statement by giving reasons and explain its working with sketch.

Last Answer : Reasons: Exhaust valve temperature in modern engine is as high as 750˚C. Thus cooling of exhaust gas becomes very important. Cooling water jackets are arranged near the valves for valve cooling. In many ... given to cooler stem as it falls back to stem again. This keeps the valve head cool.  

(i) state any two applications of I. C. Engine (ii) Draw a neat sketch of Two stroke petrol engine.

Description : (i) state any two applications of I. C. Engine (ii) Draw a neat sketch of Two stroke petrol engine.

Last Answer : Applications of I.C engine 1) In Automotive - i) Two stroke engine - Mopeds, Scooters. ii) Four stroke engine - Light vehicles, Heavy vehicles. 2) Marine Application - Ships, Boat 3) Locomotive s - ... handling system  (ii) Draw a neat sketch of Two stroke petrol engine. OR

Distinguish between overhead cam and overhead valve arrangement

Description : Distinguish between overhead cam and overhead valve arrangement

Last Answer : SR. NO. Overhead cam Overhead valve arrangement 1 This mechanism complicated in construction due to space contraint. This mechanism simpler than overhead camshaft type. 2 ... can be more accurate. Valve response is slower and valve adjustment cannot be more accurate. 

(i) Illustrate with neat sketch the working of absorber type of muffler (ii) sketch bellow type of thermostat

Description : (i) Illustrate with neat sketch the working of absorber type of muffler (ii) sketch bellow type of thermostat

Last Answer : (i) Working of absorber type of muffler: It consists of a perforated tube, around which a sound absorbing material, like fiber glass or steel wool is placed. The exhaust gases pass through the perforated tube. ... thus reducing the noise intensity.  (ii) Bellow type of thermostat:

Illustrate with neat sketch the working of battery ignition system.

Description : Illustrate with neat sketch the working of battery ignition system.

Last Answer : Battery ignition system': Figure shows line diagram of battery ignition system for a 4-cylinder petrol engine. It mainly consists of a 6 or 12 volt battery, ammeter, ignition switch, auto- ... charge is ignited-combustion startsproducts of combustion expand and produce power.    OR  

Describe the working of water/liquid cooling system with neat sketch.

Description : Describe the working of water/liquid cooling system with neat sketch.

Last Answer : A water-cooled engine block and cylinder head have interconnected coolant channels running through them. At the top of the cylinder head all the channels converge to a single outlet. A pump, driven by a ... speed increases. There is no necessity of maintaining the water up to a correct level.  

Describe the working of four stroke C. I. engine with neat sketch.

Description : Describe the working of four stroke C. I. engine with neat sketch. 

Last Answer : Working principle of CI engine: 1. Suction stroke: During this stroke, inlet valve is open and exhaust valve is closed. Only air is sucked into cylinder during this stroke. The ... burnt gases outside the combustion chamber. Crankshaft rotates by two complete revolutions through 720˚. 

Illustrate with neat sketch the construction of fuel injector

Description : Illustrate with neat sketch the construction of fuel injector

Last Answer : Diesel Fuel Injector: The injector assembly consists of - i) a needle valve ii) a compression spring iii) a nozzle iv) an injector body. When the fuel is supplied to lift the injection pump it ... and hence the valve opening pressure is controlled by adjusting the screw provided at the top.  

Show the following components in an engine with neat sketch: piston, connecting rod, valves, spark plug

Description : Show the following components in an engine with neat sketch: piston, connecting rod, valves, spark plug

Last Answer : OR

Draw a labeled sketch of pump feed fuel supply system for petrol engine and state location and function of each component.

Description : Draw a labeled sketch of pump feed fuel supply system for petrol engine and state location and function of each component.

Last Answer : The pump feed system is shown in the figure above. Fuel tank is for storage of fuel located above the engine of two wheeler and in case of car located at backside of the car ... the tendency of forming vapor lock. The system provides the fuel requirement at various engine speeds efficiently. 

Explain the working of S. U. Electrical Fuel Pump with sketch.

Description : Explain the working of S. U. Electrical Fuel Pump with sketch. 

Last Answer : S. U. Electrical Fuel Pump: Working of Electric Fuel Pump: It consists of a diaphragm which is operated electrically. By turning on the ignition switch, the solenoid winding generates ... the same process is repeated, the pump continues to operate until the ignition switch is turned off.

Describe the construction and working of of thermostat valve used in cooling system.

Description : Describe the construction and working of of thermostat valve used in cooling system.

Last Answer : Bellows type thermostat valve  Construction: It consists of metallic bellows filled with some volatile liquid like acetone, alcohol or ether which boils between 75-850C. When after start the engine is ... of plunger opens a valve in the thermostat to allow coolant to flow through the radiator. 

Describe working principle of 4 – Stroke Petrol (Engine) with sketch

Description : Describe working principle of 4 – Stroke Petrol (Engine) with sketch

Last Answer : Working of four stroke petrol engine: 1. Suction stroke: During this stroke, inlet valve is open and exhaust valve is closed. The piston moves from TDC to BDC and crank shaft rotates ... gases outside the combustion chamber. Crankshaft rotates by two complete revolutions through 7200 .

Elaborate the working of dry sump lubrication system with sketch.

Description : Elaborate the working of dry sump lubrication system with sketch.

Last Answer : Dry Sump Lubrication: Working of dry sump lubrication system: In this system, the lubricating oil is not stored in oil sump .The oil from the sump is carried to a ... engines. The pressure relief valves are used to maintain the predefined pressure value inside the lubricating system

Draw sketches showing fuel metering in the inline type F. I. P. and explain its working.

Description : Draw sketches showing fuel metering in the inline type F. I. P. and explain its working.

Last Answer : Fuel Metering in inline type fuel injection pump: The position of the plunger in the fuel injection pump can be varied by means of a control rod having a rack and pinion arrangement. By operating ... (vi) shows that no fuel is being supplied to the injector; i. e. the engine has stopped.

Draw a neat sketch of ‘Locomotive coupler’ mechanism. Explain its working in brief.

Description : Draw a neat sketch of ‘Locomotive coupler’ mechanism. Explain its working in brief.

Last Answer : Figure: Coupler Rod of Locomotive  (Link AD = Link BC = Crank Link CD = Coupling Rod Link AB = Fixed Link = Frame) Working of Coupler Rod of Locomotive: It is an ... center distance between them. This mechanism is meant for transmitting rotary motion from one wheel to the other wheel.

Describe the construction of gear drive of camshaft drive arrangement with sketch.

Description : Describe the construction of gear drive of camshaft drive arrangement with sketch.

Last Answer : Gear Drive of Camshaft Drive: Camshaft is driven by the crankshaft either by a pair of meshing gears (timing gears) or by means of a pair of timing sprocket connected by a chain ... and crankshaft to ensure opening the valves exactly at the correct time in relation to piston position. 

Sketch and label simple carburettor

Description : Sketch and label simple carburettor

Last Answer : Fig. Simple Carburettor

List any two major requirements of fuel injection system. Draw a layout of fuel injection system used in diesel engine.

Description : List any two major requirements of fuel injection system. Draw a layout of fuel injection system used in diesel engine.

Last Answer : Requirements of fuel injection system 1) Metering - The fuel injection system must measure the fuel supplied to the engine very accurately as fuel requirements vary from low to high engine speeds. 2) Time- ... and stop injection- The injection fuel must start and end quickly.  OR

Explain the working principle of the following dynamometers with suitable sketches, if necessary: (i) Hydraulic Dynamometer. (ii) Eddy Current Dynamometer.

Description : Explain the working principle of the following dynamometers with suitable sketches, if necessary: (i) Hydraulic Dynamometer. (ii) Eddy Current Dynamometer.

Last Answer : (i) Hydraulic Dynamometer: In principle, hydraulic dynamometer construction is similar to that of a fluid flywheel. Hydraulic dynamometer consists of an impeller or inner rotating member coupled to the output shaft ... Eddy current oppose the rotor motion thus loading the engine.

Explain the working of electrically driven fan in cooling engine.

Description : Explain the working of electrically driven fan in cooling engine.

Last Answer : Working of Electrically Driven Fan in Cooling Engine: The fan is driven by a separate electric motor which is supplied with power directly from the electric circuit of the engine. A thermostat switch is ... the time the fan motor remains in ON position, while 95% of the time it is off. 

Explain the working of battery ignition system with circuit diagram.

Description : Explain the working of battery ignition system with circuit diagram.

Last Answer : Battery Ignition System: Figure shows line diagram of battery ignition system for a 4-cylinder petrol engine. It mainly consists of a 6 or 12 volt battery, ammeter, ignition switch ... spark and the charge is ignited-combustion starts-products of combustion expand and produce power.   

Describe with neat sketch operation of PCV valve under different engine operating condition to control/ emission

Description : Describe with neat sketch operation of PCV valve under different engine operating condition to control/ emission

Last Answer : PCV Valve: It consists of a spring loaded tapered valve for flow control. The crankcase pressure and manifold vacuum act together to close the valve whereas the spring pressure tends to keep it open.( ... at idle and low speed (c)High speed/Load operation (d)Preventing backfire during cranking  

Describe working principle of four stroke diesel engine with the help of sketches.

Description : Describe working principle of four stroke diesel engine with the help of sketches.

Last Answer : Suction stroke: During this stroke, inlet valve is open and exhaust valve is closed. The piston moves from TDC to BDC and crank shaft rotates through 180˚. The downward movement of ... the burnt gases outside the combustion chamber. Crankshaft rotates by two complete revolutions through 720. 

(i) Illustrate the working of splash lubrication system. (ii) state any two functions of lubrication system

Description : (i) Illustrate the working of splash lubrication system. (ii) state any two functions of lubrication system

Last Answer : (i) Working of splash lubrication system: This was employed for the engine of early vehicles. It is one of the cheapest methods of engine lubrication. A scoop is made in the lowest part of the ... the engine is turned off to prevent rust and corrosion. 6. Resist sludge and varnish build-up. 

Describe the working of electrical dynamometer

Description : Describe the working of electrical dynamometer

Last Answer : Electric Dynamometer:- These may be either the i) Swinging field type  ii) Eddy current type. Working principle of eddy current dynamometer:  Figure: Working principle of Eddy ... the help of a movement arm. The load is controlled by regulating the current in the electromagnets. 

Describe the working of Idling circuit used in carburettor

Description : Describe the working of Idling circuit used in carburettor 

Last Answer : Idling or Low speed operation: The throttle valve is almost closed. Engine suction is applied at pilot petrol jet. The jet draws petrol from main jet circuit. The air is drawn from pilot air jet. ... valve is opened the suction decreased at the ideal port and is applied at slow speed opening  

Explain the working of Ackerman steering gear mechanism with neat sketch.

Description : Explain the working of Ackerman steering gear mechanism with neat sketch.

Last Answer : Working: The whole mechanism of Ackerman Steering gear is on the back of the front wheels. The Ackerman steering gear consists of turning pairs The slotted links AM and BH are attached ... each end. The steering is affected by moving CD to the right or left of its nominal position. 

Explain the working of Scotch Yoke mechanism with neat sketch.

Description : Explain the working of Scotch Yoke mechanism with neat sketch.

Last Answer : Scotch yoke mechanism. This mechanism is used for converting rotary motion into a reciprocating motion. The inversion is obtained by fixing either the link 1 or link 3. In Fig. link 1 is fixed. In this ... link 4 (which corresponds to a frame) reciprocates. The fixed link 1 guides the frame

Describe the working of EGR valve with neat sketch.

Description : Describe the working of EGR valve with neat sketch.

Last Answer : Answer: Exhaust Gas Recirculation Valve (Operation-2 marks, Sketch-2 marks) When the engine is idling, the EGR valve is closed and there is no EGR flow into the manifold. The EGR valve remains closed ... exhaust gas (less than 10% of total) to be supplied into the incoming air: fuel mixture

State the working principle of solenoid valve with neat sketch

Description : State the working principle of solenoid valve with neat sketch

Last Answer : Principle of Operation: * A solenoid is used for translating ON/OFF electrical signals to ON/OFF mechanical movements and normally used as a linear actuator. * As shown in fig (b) above, ... * When the voltage is applied to the solenoid frame magnetic field is produced in the solenoid frame. 

Draw a sketch of rack and pinion steering gear mechanism. Explain its working.

Description : Draw a sketch of rack and pinion steering gear mechanism. Explain its working.

Last Answer : Working: The rotary motion of the steering wheel is transmitted to the pinion of the steering gear through universal joints. The pinion is mesh with a rack. The circular motion of the pinion is ... relayed through the ball joints and the rods to the stub axles for the wheels to be steered.  

Draw a neat lebelled sketch of optical square. Explain its working.

Description : Draw a neat lebelled sketch of optical square. Explain its working.

Last Answer : Working of optical square1. Optical square works on principle of optical square to set perpendicular offset 2. Keep ranging rods at point B and C as shown in fig. 3. Observe the ... matched each other point D can be marked on ground and distance CD is measured as perpendicular offset.

Draw a neat sketch of optical square. Explain its working.

Description : Draw a neat sketch of optical square. Explain its working.

Last Answer : Optical Square: Working: The optical square consists of circular box 50 mm in diameter, 12.5 mm in depth. The box has three slits as A,B, and C. bb' is horizon glass, half silvered i.e ... the point on the chain line where the offset can be dropped to meet point J as shown in fig.  

Draw neat sketch of Rotameter and explain its working principle.

Description : Draw neat sketch of Rotameter and explain its working principle.

Last Answer : Rotameter: - A variable-area flowmeter is one where the fluid must pass through a restriction whose area increases with flow rate. The height of the float is directly proportional to the flowrate ... on glass tube and the flow rate can be determined by direct observation of the metering tube  

Explain the selection of lubricating oil on the basis of viscosity and service rating.

Description : Explain the selection of lubricating oil on the basis of viscosity and service rating.

Last Answer : Selection of Lubricating Oil: 1. On the basis of Viscosity : Lubricating Oils Classify in terms of Viscosity at -180C or in cold climates. a) SAE 5W b) SAE 10W c) SAE ... stability & anti- scuff Protection c) SC, SD & SC: Meets automotive manufactures specifications. 

Explain the procedure of Morse Test” to be conducted for four cylinder petrol engine.

Description : Explain the procedure of Morse Test” to be conducted for four cylinder petrol engine. 

Last Answer : Morse Test: Used for multi cylinder engines Procedure: 1. The engine is run at the required speed and the torque is measured. 2. One cylinder is cut out by shorting the plug if an S.I. engine is under test. 3. ... -B4 Total IP of Engine = I1+I2+I3+I4 Friction Power F.P. = I.P - B.P

Draw a neat sketch of 1-ph induction type energy meter and write operating principle of it.

Description : Draw a neat sketch of 1-ph induction type energy meter and write operating principle of it. 

Last Answer : Operating Principal:- The disc is placed between the two-flux due to pressure coil and flux due to current coil, which will set up torque on the disc which is proportional to power causing the ... is proportional to voltage, the second carries a current coil so its flux is proportional to current.

Describe with schematic sketch working of Vacuum operating clutch mechanism

Description : Describe with schematic sketch working of Vacuum operating clutch mechanism

Last Answer : Fig:- Vacuum Operated Clutch linkage -Vacuum operated clutch linkage operated by engine Vacuum created during suction stroke -It consists of vacuum reservoir tank connected to engine ... piston & plunger which further connected to release fork & release bearing as shown in fig

Select firing order for 4 – Cylinder engine with justification.

Description : Select firing order for 4 – Cylinder engine with justification.

Last Answer : Firing orders for 4 cylinder engine: 1-3-4-2 The firing order must be considered on the basis of engine vibrations and engine cooling. Also the firing order affects the balancing of engine ... sufficient travel time to exhaust gases. So that development of high back pressure would be avoided. 

State the materials used for piston with justification.

Description : State the materials used for piston with justification.

Last Answer : Material used for Piston: Cast Iron, Cast Steel, Forged Steel, Cast Aluminum Alloys and Forged Aluminum Alloy. Cast Aluminum Alloys is the most commonly used material for piston because; 1. Cast ... . 4. It allows to utilize more of the force produced by combustion to power the application.

Compare 2-stroke and 4 – stroke engine

Description : Compare 2-stroke and 4 – stroke engine

Last Answer : S. N. Four Stroke Engine Two Stroke Engine 1 One working stroke for every two revolutions of the crankshaft. One working stroke for each revolutions of the crankshaft 2 Turning ... Engine is air cooled 10 Engine requires more space.  Engine requires less space. 

Define volumetric efficiency.

Description : Define volumetric efficiency.

Last Answer : Volumetric efficiency: Volumetric efficiency is an indication of the breathing ability of the engine and is defined as the ratio of the air actually induced at ambient condition to the swept volume of the engine.

State any two limitations of engine cooling system.

Description : State any two limitations of engine cooling system.

Last Answer : Limitations of Engine Cooling System: 1. This is a dependent system in which water circulation in the jackets is to be ensured. 2. Power absorbed by the water pump is more and it affects ... requires considerable maintenance. 5. The failure of the system results in serious damage to the engine.

List four functions of Carburettor.

Description : List four functions of Carburettor.

Last Answer : 1. To keep the small reserve of fuel at a constant head 2. To vaporize the fuel to prepare a homogeneous air fuel mixture. 3. To supply correct amount of the air fuel mixture at the correct strength under all conditions of load and speed.

State the function of the following components. (i) Cam Shaft (ii) Crank Shaft

Description : State the function of the following components. (i) Cam Shaft (ii) Crank Shaft

Last Answer : Camshaft: The camshaft is a mechanical component of an internal combustion Engine. It opens and closes the inlet and exhaust valves of the engine at the right time, with the exact ... translate the linear reciprocating motion of a pistons into the rotational motion required by the automobile.