Recent questions tagged automobile-engine

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. 

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.

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.

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.

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.  

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. 

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. 

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.

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.   

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. 

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 .

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

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.

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. 

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.

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.

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.

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.

Description : Define Clearance Volume and Swept Volume

Last Answer : Clearance Volume: Clearance volume is a volume between the cylinder head and the piston top when the piston is at top dead center (TDC). OR It can also be defined as the volume of ... displacement volume or Swept volume It is expressed in terms of cubic centimeter (cm3) and given by

Description : Classify lubricating oil using viscosity (SAE) and load severity (API) rating.

Last Answer : 1.On the basis of Viscosity : i. Lubricating Oils Classify in terms of Viscosity at -18 0C or in cold climates. a) SAE 5W b) SAE 10W c) SAE 20 W ii. Lubricating Oils Classify ... sum oxidation stability & anti- scuff c. protection d. SC, SD & SE: Meets automotive manufactures specifications. 

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

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. 

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

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

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 push ... close. A spring (attached to the valve) returns the valve to its seated position.   

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. 

Description : Select type of a muffler for a motorcycle engine with justification.

Last Answer : Type of a muffler for a motorcycle engine 1. Baffle type 2. Resonance type 3. Absorber type Multiple Baffle Silencers In a multiple baffle silencer, the exhaust gas escapes ... absorbing material reduces the high pressure fluctuation of the exhaust gases thus reducing the noise intensity. 

Description : Differentiate between dry liner and wet liner,

Last Answer : Sr No. Dry liner Wet liner 1 Dry liner is not in direct contact with of cooling water Wet liner is in direct contact with of cooling water cooling water 2 ... A dry liner cannot be finished accurately before fitting A wet liner can be finished accurately before fitting

Description : List different applications of I.C.engines.

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 – Railways. 4. Stationery engines – For lifting water, Generator, Material handling systems

Description : State the functions following ignition system components (i) Ignition coil (ii) Distributor (iii)Condenser (iv)Spark plug

Last Answer : Functions following ignition system components: (i) Ignition coil: Ignition coil receives voltage from primary circuit and convert it to very high voltage up to 28000 volts required for spark by means of ... Charge of air and petrol is ignited by means of the spark produced by spark plug.

Description : State the functions and materials of following engine components: (i) Piston (ii) Connecting rod (iii)Crank shaft (iv)Exhaust manifold

Last Answer : Engine components Material Functions Piston Cat aluminum alloy To transmit the force of explosion to the crankshaft. To form seal so that the high pressure gases in ... atmosphere through the exhaust pipe after combustion stroke is completed. To keep back pressure minimum.

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. 

Description : Distinguish between air cooling system and water cooling system.

Last Answer : Sr. No.  Air cooling System Water cooling system 1 In this system cooling medium used is Air In this system cooling medium used is Water 2 The engine design is simple The ... air cooled engine. 9 Examples: Bikes, Scooters etc. Examples: Cars, Buses, Trucks etc.

Description : State the functions of nozzles. Classify nozzles used in diesel engine.

Last Answer : Functions of nozzle:  1) To atomize fuel by converting it in to fine droplets. 2) To convert pressure energy in to kinetic energy. 3) To inject the fuel at right quantity at right time with ... Single hole nozzle 2) Multi-hole nozzle 3) Long stem nozzle 4) Pintle nozzles 5) Pintuax nozzles

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.  

Description : Write the specifications of I.C. engine used in a two wheeler four stroke vehicle.

Last Answer : Engine specifications for two wheeler 1. Engine of Bajaj Discover 125 ST - Air-cooled, 4-stroke 124.6 cc engine - Maximum power of 12.8 Bhp at 9000 rpm - Maximum torque of 11 Nm at 7000 rpm OR 2. Honda Livo a) BS- ... rpm. d) Bore x Stroke - 50 x 55.6 mm e) C R - 9.9 : 1, Max Speed - 86KMPH

Description : Define Indicated power

Last Answer : Indicated power: (I.P.) : The power developed with in the engine cylinders is called indicated power. This is calculated from the area of the engine indicator diagram. It is usually expressed in kilowatts (kW).  Indicated Power= nPLAN/60×1000 kW

Description : State the need of cooling system of I.C.engine.

Last Answer : Need of cooling system : The cooling system is needed to keep the engine from not getting so hot as to cause problems and yet to permit it to run hot enough to ensure maximum efficiency of ... provided to prevent the damage of mechanical parts as well as to obtain maximum performance of the engine.

Description : State four functions of exhaust system.

Last Answer : 1) The function of an exhaust is to expel the exhaust gases from the combustion chamber of each cylinder out to the atmosphere through the exhaust pipe after combustion stroke is completed. 2) To keep back pressure minimum.

Description : List all the components of petrol fuel supply system.

Last Answer : Components of Petrol fuel supply system: 1) Fuel Tank 2) Flexible fuel line 3) Fuel tank to fuel pump line 4) Fuel pump 5) Fuel filter 6) Carburetor or Injector

Description : List any four components of C.I. engine.

Last Answer : Components of C.I. engine. 1. Engine Head 2. Crankshaft 3. Camshaft 4. Engine block 5. Fuel injector 6.Fuel Pump 7.Fuel Distributor 8. Cylinder liner 9. Piston

Description : Classify I.C. engine on the basis of cycle of operation and cylinder arrangement.

Last Answer : 1) Cycle of operation:- a) Otto cycle engine b) Diesel cycle engine c) Duel combustion cycle engine or semi- diesel cycle engine. 2) Arrangement of cylinder:- a) Vertical engine b) horizontal engine c) Radial engine d) V-engine e) Opposed cylinder engine 

Description : Define the terms: swept volume.

Last Answer : Swept Volume: The volume swept by the piston is moving from T.D.C. to B.D.C. It is expressed in terms of cubic centimeter (cm3 ) and given by S=A X L= (π/4) d2 x L

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:

Description : (i) Describe the principle of mechanical governor in fuel injection pump. (ii) State four types of injector nozzles

Last Answer : (i) Working Principal of mechanical governor of FIP: The working principle of mechanical governor is illustrated in figure. When the engine speed tends to exceed the limit the weights fly apart. This causes ... ) Multi-hole nozzle 3) Long stem nozzle 4) Pintle nozzles 5) Pintuax nozzles 

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. 

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  

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  

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. 

Description : Sketch and label simple carburettor

Last Answer : Fig. Simple Carburettor

Description : State any four requirements of gasket

Last Answer : Requirement of Gasket: Gaskets are used to provide a tight fitting joint between two surfaces. For example, the joint between cylinder head and block. 1. Conformity: - The gaskets must be able ... Provision of apertures: - The gasket must have apertures for any studs, bolts, opening etc.