List four drawback of carbureted SI Engine.

List four drawback of carbureted SI Engine.
by

1 Answer

Answer :

Drawback of Carbureted SI Engine: 1) Air-Fuel Ratio: As in SI engine Air-fuel ratio varies from 8:1 to 18.5:1 i.e. from 8 kg of air/kg of fuel to 18.5 kg of air/kg of fuel. Richer or leaner air-fuel ratio limit causes the engine to misfire, or simply refuse to run at all. 2) Fuel consumption: As atomization rate deepened upon velocity of air in venture also As in SI engine Air-fuel ratio varies from 8:1 to 18.5:1 so Fuel consumption is more in SI engine. 3) Power output: Power output varies due to variation of Air-fuel ratio. 4) Emission: As in SI engine Air-fuel ratio varies from 8:1 to 18.5:1 i.e. from 8 kg of air/kg of fuel to 18.5 kg of air/kg of fuel. So emission is more in SI engine.

by

Related questions

List two drawbacks of carbureted SI engine during fuel distribution and drivability.

Description : List two drawbacks of carbureted SI engine during fuel distribution and drivability.

Last Answer : Fuel distribution : Drawbacks 1. Mal-distribution of charge. 2. Inaccurate metering of charge. 3. Fuel atomization depends upon velocity of air in the venture. Drivability: Drawbacks 1 ... temperature compensation. 4) No compensation of Exhaust gas recirculation. 5) Backfiring may take place.

State four drawbacks of carbureted SI engine

Description : State four drawbacks of carbureted SI engine 

Last Answer : Drawbacks of carbureted SI engine: 1) No altitude compensation. 2) Mal-distribution of charge. 3) Variation in air: fuel ratio. 4) Inaccurate metering of charge. 5) Does not meet emission ... in poor efficiency. 10) Backfiring may take place. 11) Carburetor Icing may take place.

Enlist drawbacks of carbureted (SI) Engine on the basis of emission fuel Consumption, Air fuel ratio and fuel distribution.

Description : Enlist drawbacks of carbureted (SI) Engine on the basis of emission fuel Consumption, Air fuel ratio and fuel distribution.

Last Answer : Drawbacks of carbureted (SI) Engine. Parameter Drawbacks Emission Does not meet emission Norms Fuel consumption Due to absence of throttling specific fuel consumption is ... distribution of charge. Fuel distribution for each cylinder is not equal for multi cylinder engine.

Discuss the drawbacks of carbureted SI engine on the base of, Air-fuel ratio, fuel consumption, power output, emission.

Description : Discuss the drawbacks of carbureted SI engine on the base of, Air-fuel ratio, fuel consumption, power output, emission. 

Last Answer : 1) Air-fuel ratio: - As in SI engine Air-fuel ratio varies from 8:1 to 18.5:1 i.e. from 8 kg of air/kg of fuel to 18.5 kg of air/kg of fuel. Richer or leaner air-fuel ratio limit causes the engine to ... 8 kg of air/kg of fuel to 18.5 kg of air/kg of fuel. So emission is more in SI engine.

Describe three engine modifications to be done to reduce SI engine Emission.

Description : Describe three engine modifications to be done to reduce SI engine Emission.

Last Answer : Engine Modifications to be Done to reduce SI Engine Emission are: 1. Use of leaner air-fuel ratios: The carburettor may be modified to provide relatively lean air fuel mixtures during ... tolerances and using special type of carburettors. This also includes fuel injection in manifold.

Compare the SI and CI engine on the basis of: (i) Compression Ratio (ii) Operating Speed (iii) Power O/P per weight.

Description : Compare the SI and CI engine on the basis of: (i) Compression Ratio (ii) Operating Speed (iii) Power O/P per weight.

Last Answer : Parameter SI Engine CI Engine (i) Compression Ratio Compression ratio is low, about 10:1 limited by detonation Compression ratio is higher, about 18:1 to 22:1 (ii) ... due to lower compression ratio. Power output is more than SI engine due to higher compression ratio.

State the drawbacks of carbureted (SI) engines on the basis of fuel distribution, emission, power output and fuel consumption.

Description : State the drawbacks of carbureted (SI) engines on the basis of fuel distribution, emission, power output and fuel consumption.

Last Answer :  Drawbacks of carburetted S.I. engine: 1) Fuel distribution- Mal-distribution of charge. 2) Emission- More emissin 3) Power output- Less 4) Fuel consumption - More

Compare carbureted engine with MPFI engine

Description : Compare carbureted engine with MPFI engine

Last Answer : Sr.  Carbureted fuel system Electronic fuel injection system 1 Mal-distribution of charge.  Uniform distribution of charge.  2 Due to resistance in intake manifold volumetric ... is take place inside the manifold. Fuel being injected into or close to the cylinder. 

Compare carbureted engine fuel supply system with MPFI system.

Description : Compare carbureted engine fuel supply system with MPFI system.

Last Answer : Sr.No. Carbureted fuel supply system MPFI fuel supply system 1 Mal-distribution of charge.  Uniform distribution of charge.  2 Due to resistance in intake manifold volumetric ... is take place inside the manifold. fuel being injected into or close to the cylinder. 

LPG is used as a fuel for petrol engine. Justify your answer.

Description : LPG is used as a fuel for petrol engine. Justify your answer.

Last Answer : LPG is used as a fuel for petrol engine, because of its following advantages  1. It is cheaper than petrol 2. It is highly detonation resistant and does not pre-ignite easily. 3. It gives ... modified. LPG kits are readily available (even for MPFI engines) and the kit cost is mostly affordable. 

Describe the Air Fuel Ratio in CI Engine.

Description : Describe the Air Fuel Ratio in CI Engine.

Last Answer : Air Fuel Ratio in CI Engine: Thermodynamic analysis of the engine cycles has clearly established that operating an engine with a leaner air-fuel ratio always gives a better thermal efficiency but the ... always designed to operate with an excess air of 15 to 40% depending upon the application.

Rated speed of an engine is the speed at which an engine devlopes (A) Maximum crankshaft torque (B) Maximum brake horse power output (C) Maximum thermal efficiency (D) Maximum drawback pull

Description : Rated speed of an engine is the speed at which an engine devlopes (A) Maximum crankshaft torque (B) Maximum brake horse power output (C) Maximum thermal efficiency (D) Maximum drawback pull

Last Answer : (B) Maximum brake horse power output

List two disadvantages and advantages of CNG

Description : List two disadvantages and advantages of CNG

Last Answer : Dis - advantages: 1. Low engine performance. 2. Low engine volumetric efficiency. 3. Need of large pressurized fuel storage tank. 4. Refuelling is a slow process 5. Inconsistent fuel properties ... toxic. 11. CNG is lighter than air and so Dissipates into atmosphere implies less chance of fire

Describe any four methods to improve fuel economy.

Description : Describe any four methods to improve fuel economy. 

Last Answer : Methods to Improve Fuel Economy: 1. Use of multi-functional fuel additives will provide 3 to 4% fuel economy. 2. Good driving habits. 3. Properly maintained fuel supply system. 4. ... computer controlled ignition system. 6. Use of higher voltage automotive electrical system (42 volts system).

State four method to control diesel smoke.

Description : State four method to control diesel smoke.

Last Answer : Methods to Control Diesel Smoke : 1. De-rating:- At lower loads, the air: fuel ratio obtained will be leaner & hence the smoke developed will be less. However this means a loss ... the intake manifold. This shortens the delay period- curbs thermal cracking which is responsible for soot format 

A two stroke engine has a speed of 750 rpm. A four stroke engine having an identical cylinder size runs at 1500 rpm. The theoretical output of the two stroke engine will (a) Be twice that of the four stroke engine (b) Be half that of the four stroke engine (c) Be the same as that of the four stoke (d) Depend upon whether it is a CI or SI engine

Description : A two stroke engine has a speed of 750 rpm. A four stroke engine having an identical cylinder size runs at 1500 rpm. The theoretical output of the two stroke engine will (a) Be twice that of the four stroke ... ) Be the same as that of the four stoke (d) Depend upon whether it is a CI or SI engine

Last Answer : Ans :c

State four properties of SI engine fuel.

Description : State four properties of SI engine fuel.

Last Answer : 1. It should mix readily with air and provide uniform manifold distribution. That is, it should easily vaporize. 2. It must be knock resistant. 3. It should not pre-ignite easily. 4. It should ... not form gum and varnish. OR 1. Volatility2. Knock Resistivity 3. Sulphur Content 4. Gum Content

Describe four properties of gasoline as a fuel for SI engine

Description : Describe four properties of gasoline as a fuel for SI engine

Last Answer : Volatility: volatility depend upon fractinal composition of fuel. Method of measuring volatility has been standardized by ASTM ( American society of Testing Materials) and the graohical representation ... gasoline to improve the gasoline stability during storage by inhibiting the formation of gums.

Explain with sketch working of electronic petrol injection system. State its advantages over carbureted fuel system.

Description : Explain with sketch working of electronic petrol injection system. State its advantages over carbureted fuel system. 

Last Answer : Working of Electronic Fuel injection system: Because mechanical injection systems have limited adjustments to develop the optimal amount of fuel into an engine that needs to operate under a variety of different ... (acceleration). 7. Compact design of fuel supply system. 8. Modular design

The most important drawback of sucralfate in the treatment of duodenal ulcer is: A. Low ulcer healing efficacy B. Poor relief of ulcer pain C. High incidence of side effects D. Need for taking a big tablet four times a day

Description : The most important drawback of sucralfate in the treatment of duodenal ulcer is: A. Low ulcer healing efficacy B. Poor relief of ulcer pain C. High incidence of side effects D. Need for taking a big tablet four times a day

Last Answer : D. Need for taking a big tablet four times a day

Describe the idle speed control function of an electronic control module with neat sketch.

Description : Describe the idle speed control function of an electronic control module with neat sketch.

Last Answer : Idle Speed Control System as Output Function of ECM: While the engine is being started, or operated, the logic module of Electronic Control Module (ECM) will signal the Stepper motor of Idle Speed ... speed control valve stepper motor allows 125 possible valve opening positions. OR

Describe the working of high pressure pump used in CRDI system.

Description : Describe the working of high pressure pump used in CRDI system.

Last Answer : Working of High Pressure Fuel Pump Used In CRDI System: * The fuel inlet to the pump is controlled by the SCV (suction control valve) through the EDC * The rotation of the inner cam pushes ... maintained in the common rail. Figure: Sectional View of High Pressure Pump used in CRDI System

Describe the working of electronic fuel injector with the help of suitable sketch.

Description : Describe the working of electronic fuel injector with the help of suitable sketch.

Last Answer : Working of Electronic Fuel Injector: In MPFI system, Top feed fuel Injector is used. These injectors are solenoid-operated valves that are opened and closed by means of electric pulses from the ECU. The ... Pintle and discharge opening to form a fine spray pattern that has a cone shape.

Describe the working of PCV System.

Description : Describe the working of PCV System.

Last Answer : Working of PCV system:  During normal compression stroke, a small amount of gases in the combustion chamber escapes past the piston. Approximately 70 % of these blow-by' gases ... , crankcase ventilation performance is optimized, while engine performance and drivability remains unaffected. 

Sketch and describe the layout of series hybrid vehicles.

Description : Sketch and describe the layout of series hybrid vehicles. 

Last Answer : Series-Hybrid vehicle  In Series Hybrid vehicles, the Internal Combustion Engine (ICE) drives a generator, which charges the battery and supplies current to the electronically controlled motor. The ... drive have to be rated to the maximum power. It has low overall system efficiency.

Describe the procedure to locate leakage in Compressed Natural Gas Fuel supply system of a car. State relevant precaution.

Description : Describe the procedure to locate leakage in Compressed Natural Gas Fuel supply system of a car. State relevant precaution.

Last Answer : Procedure to locate Leakage in Compressed Natural Gas Fuel Supply System of a Car: 1. The first indicator is the foul smelling agent present in CNG.. 2. The second level of test you can do is to take a ... , incense sticks, etc. 2. Close the CNG regulator and 3. Put the safety cap on the cylinder.

Describe the working of pressure regulation in PFI system with the help of schematic diagram.

Description : Describe the working of pressure regulation in PFI system with the help of schematic diagram.

Last Answer : Working of Pressure Regulator in PFI System: The fuel pump provides more fuel than the maximum required by the engine. Fuel not used by the engine is returned to the fuel tank. The fuel rail supplies all injectors. ... between 2.0 and 3.5 bar and allows excess fuel to return to the fuel tank.

Describe features of Variable Valve Timing Mechanism (VVT)

Description : Describe features of Variable Valve Timing Mechanism (VVT)

Last Answer : Features of VVT: Variable valve timing (VVT) is a system for varying the valve opening of an internal combustion engine. This allows the engine to deliver high power, but also to work tractably ... actually driven by that fast cam. Therefore, fast timing and high lift are obtained in both valves 

Sketch and describe LPG fuel supply system layout.

Description : Sketch and describe LPG fuel supply system layout.

Last Answer : Figure: LPG Fuel Supply System Layout for SI Engine.  The system works by pumping LPG at high pressure from the LPG vehicle tank to the engine inlet manifold via a set of liquid ... intake manifold. The fuel vaporizing in the intake manifold cools and increases the density of the intake air.

Describe operation of CRDI system.

Description : Describe operation of CRDI system.

Last Answer : Operation of CRDI System: High pressure pump provides high pressure fuel to the common rail. The common rail stores the fuel and maintains a constant pressure in the common rail line (approximately 1500 bars ... needle movement.  Figure: Layout of Common Rail Fuel System for Diesel Engine

Illustrate with example of fuel injection as an output control function of ECM.

Description : Illustrate with example of fuel injection as an output control function of ECM.

Last Answer : Fuel Injection as an Output Control Function of ECM: ECM controls fuel injection by calculating A: F ratio needed for engine. Engine requires different air fuel ratios while cranking, warm- up, idle, ... open, allowing enough air into the engine for start and idle (Throttle body valve is closed).

State the function and location of oxygen sensor and mass air flow sensor.

Description : State the function and location of oxygen sensor and mass air flow sensor. 

Last Answer : Name Function Location Oxygen Sensor Measuring quantity of oxygen in exhaust  Located at inlet and outlet side of catalytic convertor Mass Air Flow Sensor It is used to tell ECU the mass of air entering the engine. Mounted between air filter and turbocharger.

State the effect of detonation.

Description : State the effect of detonation.

Last Answer : Effects of Detonation: 1. Noise and roughness: Mild knock is seldom audible and is not harmful. When intensity of knock increases a loud pulsating noise is produced due to development of a ... and combustion chamber wall and this overheating leads to ignite the charge before the passage of spark.

State the general conditions necessary for combustion.

Description : State the general conditions necessary for combustion.

Last Answer : Three things are required in proper combination before ignition and combustion can take place Heat, Oxygen and Fuel. There must be Fuel to burn. There must be Air to supply oxygen. There must be Heat (ignition temperature) to start and continue the combustion process.

What can cause my 1994 Honda prelude si not to crank but the engine turns over?

Description : What can cause my 1994 Honda prelude si not to crank but the engine turns over?

Last Answer : If it turns over slowly it can still be the battery or, lesslikely, the starter. If its turn over is lively it's probably inthe electrical system, maybe the computer.

Ignition timing of a multi-cylinder SI engine can be adjusted by A. rotating the cam shaft B. adjusting the generator pulley C. rotating the distributor D. adjusting the pump pulley

Description : Ignition timing of a multi-cylinder SI engine can be adjusted by A. rotating the cam shaft B. adjusting the generator pulley C. rotating the distributor D. adjusting the pump pulley

Last Answer : ANSWER : C

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

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

The compression ratio in a Spark Ignition (SI) engine is generally in between a. 7 to 10 b. 10 to 14 c. 14 to 18 d. 18 to 22 (Ans:a)

Description : The compression ratio in a Spark Ignition (SI) engine is generally in between a. 7 to 10 b. 10 to 14 c. 14 to 18 d. 18 to 22 (Ans:a)

Last Answer : Which of the following is not true for two stroke engine as compared to four stroke engine? a. Less cooling is required b. Greater lubrication is required c. More uniform torque on crankshaft d. Complete exhaust of products of combustion (Ans:a)

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%

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

In a variable speed SI engine, the maximum torque occurs at the maximum (a) Speed (b) Brake power (c) Indicated power (d) Volumetric efficiency

Description : In a variable speed SI engine, the maximum torque occurs at the maximum (a) Speed (b) Brake power (c) Indicated power (d) Volumetric efficiency

Last Answer : Ans :d

Velocity of flame propagation in SI engine is maximum for a fuel air mixture which is (a) 10% richer than stoichiometric (b) Equal to stoichiometric (c) More than 10% richer than stoichiometric (d) 10% leaner than stoichiometric

Description : Velocity of flame propagation in SI engine is maximum for a fuel air mixture which is (a) 10% richer than stoichiometric (b) Equal to stoichiometric (c) More than 10% richer than stoichiometric (d) 10% leaner than stoichiometric

Last Answer : Ans :a

In a SI engine, which one of the following is the correct order of the fuels with increasing detonation tendency? (a) Paraffins, olefins, naphthenes, aromatics (b) Aromatics, naphthenes, paraffins, olefins (c) Naphthenes, olefins, aromatics, paraffins (d) Aromatics, naphthenes, olefins, paraffins

Description : In a SI engine, which one of the following is the correct order of the fuels with increasing detonation tendency? (a) Paraffins, olefins, naphthenes, aromatics (b) Aromatics, naphthenes, paraffins, olefins (c) Naphthenes, olefins, aromatics, paraffins (d) Aromatics, naphthenes, olefins, paraffins

Last Answer : Ans :d

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

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

Reference fuels for knock rating of SI engine fuels would include (a) Iso octane alpha methyl naphthalene (b) Normal octance and aniline (c) Isooctance and n octane (d) N heptane and iso octane

Description : Reference fuels for knock rating of SI engine fuels would include (a) Iso octane alpha methyl naphthalene (b) Normal octance and aniline (c) Isooctance and n octane (d) N heptane and iso octane

Last Answer : Ans : d

For the same capacity engines, the compression ratio of diesel engine a. is lower than the compression ratio of SI engine b. is higher than the compression ratio of SI engine c. is same as the compression ratio of SI engine d. cannot say

Description : For the same capacity engines, the compression ratio of diesel engine a. is lower than the compression ratio of SI engine b. is higher than the compression ratio of SI engine c. is same as the compression ratio of SI engine d. cannot say

Last Answer : ANSWER b. is higher than the compression ratio of SI engine

How the efficiency of the SI engine is affected by the specific heat ratio (γ) of the working fluid? a. the efficiency of the engine increases with increase in specific heat ratio (γ) of the working fluid b. the efficiency of the engine decreases with increase in specific heat ratio (γ) of the working fluid c. the efficiency of the engine does not affected by change in specific heat ratio (γ) of the working fluid d. none of the above

Description : How the efficiency of the SI engine is affected by the specific heat ratio (γ) of the working fluid? a. the efficiency of the engine increases with increase in specific heat ratio (γ) of the working ... not affected by change in specific heat ratio (γ) of the working fluid d. none of the above

Last Answer : ANSWER a. the efficiency of the engine increases with increase in specific heat ratio (γ) of the working fluid

For operation of power tiller, the power is obtained from the . A. Batteries C. IC engine B. SI engine D. All of the above

Description : For operation of power tiller, the power is obtained from the . A. Batteries C. IC engine B. SI engine D. All of the above

Last Answer : IC engine

What is mean by ignition limit? Give ignition limit for SI engine.

Description : What is mean by ignition limit? Give ignition limit for SI engine.

Last Answer : Ignition Limit corresponds approximately to that mixture ratio, at lean & rich ends of the scale, where the heat released by spark is no longer sufficient to initiate combustion in the neighboring un-burnt mixture. ... 7:1 to 30:1 Actual Ignition limits for hydrocarbon fuels are 9:1 to 21:1

Draw P-Q diagram for stages of combustion in SI engine and write stages of combustion with its explanation.

Description : Draw P-Q diagram for stages of combustion in SI engine and write stages of combustion with its explanation.

Last Answer : The stages of combustion in S.I. engine: Stage I: Ignition Lag or Preparation Phase: It is a chemical process which depends on-nature of fuel, temperature & pressure, ... The rate of combustion reduces due to surface of the flame front becoming smaller and reduction in turbulence.

What is meant by surface ignition in SI engine?

Description : What is meant by surface ignition in SI engine? 

Last Answer : Surface ignition: Surface ignition is the ignition of the fuel-air mixture by a hot spot on the combustion chamber walls such as on overheated valve or spark plug or glowing combustion Chamber ... and start propagates across the chamber in an analogous manner to what occurs in normal knock.