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

1 Answer

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. The speed falls because of the lass of power with one cylinder cut out but is restored by reducing the load.

4. The torque is measured again when the speed has reached its original value.

5. If the value of I.P. measured simultaneously for each cylinder

In this method the BP of whole engine is first of all measured at a certain speed and load with the help of dynamometer. Then from total number of cylinders of the engine one of the cylinders is cut out by short circuiting the spark plug. The output is measured by keeping the speed constant. The difference in the outputs is measure of the indicated power of disconnecting cylinders. Thus for each cylinder the IP is obtained and then is added together to find the total IP of the engine.

Where BP= Brake power

IP= Indicated power

FP = Frictional power

Let F.P. of cylinder 1,2,3,4 be F1, F2, F3, F4 respectively.

Then total FP of engine = F1+F2+F3+F4

Let IP of cylinder 1 2 3 and 4 be I1, I2 I3& I4 respectively.

The total IP of engine is given by,

IP= I1 +,I2+ I3 + I4

The total BP of engine when all cylinders are working

BP= Total IP – Total FP

B = (I1 +,I2+ I3 + I4)–(F1+F2+F3+F4)----------1

When cylinder 1 is cut off, the BP developed by the remaining three cylinders,

B1= (0+,I2+ I3 + I4)–(F1+F2+F3+F4)------------2

Subtracting (2) from (1) we get

B- B1 = I1

Therefore, IP of cylinder 1, I1 = B-B1

Similarly ,

IP of cylinder 2, I2 = B-B2

IP of cylinder 3, I3= B-B3

IP of cylinder 4, I4 = B-B4

Total IP of Engine = I1+I2+I3+I4

Friction Power F.P. = I.P – B.P


Related questions

Description : Morse test is conducted on the engine to calculate the mechanical efficiency of A. single cylinder CI engine B. single cylinder SI engine C. only on two stroke engines D. multi cylinder engine

Last Answer : ANSWER : D

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 : 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 : 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 : (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

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 : 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 : State the common firing orders used in 4 cylinder engine.

Last Answer : Firing order: The sequence in which the power impulses occur in an engine is called the firing order. Firing order for 4 cylinder engine.(Any one) 1-3-4-2 OR 1-2-4-3 OR 1-4-3-2 

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 : 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 : 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 : 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˚. 

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 : In a morse test for a 2 cylinder, 2 S SI engine, the brake power was 9 kW. Whereas the brake power of individual cylinders with spark cut off were 4.25 kW and 3.75 kW. The mecheffic of the engine is (a) 90% (b) 80% (c) 45.5% (d) 52.5%

Last Answer : Ans :a

Description : The method of determination of indicated power of multi cylinder SI engine is by use of (a) Morse test (b) Prony brake test (c) Motoring test (d) Heat balance test

Last Answer : Ans : a

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

Last Answer : OR

Description : Classify I. C. Engine on the basis of -Cycle of operation -Method of cooling

Last Answer : Classification of I. C. Engine on the basis of  -Cycle of operation: a) Otto cycle engine b) Diesel cycle engine c) Duel combustion engine or semi-diesel cycle engine -Method of cooling: a) air cooled engine b) water cooled engine 

Description : Define internal combustion engine

Last Answer : Definition of I. C. engine: The I. C. engine means Internal combustion engine in which combustion i.e. burning of fuel in presence of air takes place inside the combustion chamber (closed volume). 

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 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 : (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 : 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.

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 : 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 : 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 : 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 : 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 : 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 : 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 : 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 : 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 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 : 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 : 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.