The document is a project presentation on the maintenance and analysis of a two-stroke SI engine, detailing its components, maintenance procedures, and experimental methodologies. It outlines the engine's functioning, tests conducted on the engine, and includes advantages and disadvantages of using a two-stroke engine. Additionally, the document contains specifications for the test rig, observation tables, and precautions for safe operation.

1. PROJECT PRESENTATION ON
MAINTENANCE & ANALYSIS OF TWO-STROKE S.I ENGINE
PRESENTED BY
Group-3rd
Regd. No.- 1101224144 to 4163
Section-A & B
7th Semester
Mechanical Engineering
MAJHIGHARIANI INSTITUTE OF TECHNOLOGY &
SCIENCE

2.  CONTENTS
1. INTRODUCTION
2. COMPONENTS
3. MAINTENANCE OF TWO STROKE SI ENGINE
4. SPARK PLUG
5. HOSE PIPE
6. SILENCER
7. U-TUBE MANOMETER
8. PETROL TANK
9. INLET WATER FLOW FROM PIPE
10.OUTLET WATER FLOW FROM PIPE
11.LOAD ARRENGMENT
12.HOW THE ENGINE WORKS
13.OBSERVATION TABLE
14.ADVANTAGES AND DISADVANTAGES
15.PRECAUTIONS

3.  A two-stroke engine is a type of Internal combustion engine which completes a power
cycle in only one crankshaft revolution and with two stroke, or up down movements of
the piston.
 In two stroke S.I engines the crankcase is a pressurization chamber to force fuel/oil/air
into the cylinder.
 Oil and gas mixture are used as a lubricate internal part.
 A Carburetor is used for mixing of air fuel ratio according to the requirement of the
engine.
 Spark plug is placed at the top of the engine head for ignition purpose.
 INTRODUCTION

4.  Spark plug.
 Crankshaft.
 Connecting rod.
 Transfer port.
 Combustion chamber.
 Air cooling system.
 Piston.
 Intake and exhaust port.
continue…
 COMPONENTS

5.  MAINTENANCE OF TWO STROKE SI ENGINE

6.  SPARK PLUG
 The function of the spark plug is to introduce the
ignition energy into the combustion chamber
and to initiate combustion of the compressed air-fuel
mixture.
 It accomplishes this task by generating a spark
between its electrodes, which then generates the
required heat to ignite a smooth burn of the air/fuel
mixture.
 The spark plug is an important factor in determining
optimal performance and reliable functioning of an
engine.

7.  HOSE PIPE
 Its function is pass the air from surrounding
to carburettor

8.  SILENCER
 The main function of Silencer is to reduce noise & to
transmit exhaust gasses to the atmosphere BUT it also
serves some more function
1. Decrease fuel consumption
2. Exhaust gasses in the Silencer can be used to
produce some power that can charge the Battery of
your vehicle

9.  U-TUBE MANOMETER
 U-tube manometer is made up of two parallel tubes joined
together in the form of the letter “U.”
 The two parallel tubes basically constitute the limbs
of the device. Whether it’s for the measurement of pressure
in a fluid, liquid, or gas.
 U-tube manometer is simply attached as shown in the diagram
below. The liquid level rises by a height h in the tube with the
open end, over the point where the pressure is being measured.
The height h is monitored and calculated such that the pressure
exerted at the point equals the pressure exerted by the column h.
p = ρgh

10.  PETROL TANK
 A Petrol tank is a safe container for flammable
fluid.
 The term is typically applied to part of an engine
system in which fuel is stored and propelled or
released into an engine
 The system must contain a given quantity of fuel and
must avoid leakage and limit evaporative emissions.

11.  INLET WATER FLOW FROM PIPE
 Through this pipe water is circulated inside
the silencer for measuring the inside temperature.

12.  OUTLET WATER FLOW FROM LEVEL PIPE
 Through this pipe a inside circulating water is exist
in drain

13.  LOAD ARRANGEMENT (WATER REHOSTAT ASSEMBLY)
 The Dynamic test rig consists of two stroke petrol
engine coupled to electrical dynamometer.
 A water rehostat is provided to load the engine,
various measurements are provided so that
performance of the engine at various loads and
speed can be estimated.

14.  HOW THE ENGINE WORKS
 The two stroke engine employs the crankcase as
well as the cylinder to achieve all the elements of
the cycle in only two strokes of the piston.
 360 degrees rotation of crankshaft
completes the cycle.

15.  TWO STROKE PETROL ENGINE TEST RIG
(WITH ELECTRICAL DYNAMOMETER)

16.  Petrol engines are widely used for various applications. Two stroke petrol engine are preferred
especially for automobiles, because of their higher power to weight ratio and smooth operation,
The ‘DYNAMIC’ test rig consists of a two stoke petrol coupled to electrical dynamometer. A
water rheostat is provided to load the engine, various measurements are provided so that
performance of the engine at various loads and speed can be estimated
 SPECIFICATIONS
1. Engine- Two stroke, single cylinder, horizontal air cooled engine developing 4.5 HP at 6400
rpm(blower speed), supplied along with the gear box.
2. Dynamometer- 2.5 KVA capacity A.C generator, belt connected to the engine with water
rheostat.

17. 3. Measurement & Controls-
(a) Calibrated burette for fuel intake measurement.
(b) Orifice meter (Dia. 16 mm) with water manometer for air intake measurement.
(c) Exhaust gas calorimeter to measure heat carried away by exhaust gases.
(d) Multichannel digital temperature indicator.
(e) Voltmeter to measure output voltage of A.C. generator.
(f) Measuring flask to measure to water flow rate of engine calorimeter.
 EXPERIMENTAL PROCEDURE
1. Put sufficient petrol along with 2% self mixing 2T oil in the tank.
2. Check oil level in the gear box of the engine. If necessary add up SAE-40 oil. oil level
should always be up to the oil filling hole.
3. Fill up water in water rheostat to a required height and add salt. (approximately 500 gm in
filled water tank.)

18. 4. Conform that the engine is in neutral gear, put off main switch of rheostat and ignition switch
of engine is ‘ON’.
5. Start water supply to calorimeter.
6. Press the choke knob and give a sharp kick, engine will start . As the engine starts, release
the choke knob, pull the clutch lever and put the engine in 4th gear.
7. Slowly increase the accelerator and set the generator speed to 700 rpm.
8. Slowly rotate the loading knob (on panel) in clock wise direction so that the engine gets
loaded. (take sufficient load).
9. Fill the burette with burette filling cock. Note down time for 10 ml fuel consumption,
manometer difference, ammeter and voltmeter reading and calorimeter water flow rate.
10. Note down the temperature from T1 to T4.
11. Increase the load, adjust the engine speed and note down the readings.
12. Repeat the procedure for different speeds

19.  OBSERVATION TABLE
Sr. No. 1 2 3
Engine Speed, N rpm 1395 2860 2650
Ammeter, I amps. 12 5 2
Voltmeter, V volts 110 20 10
Time for 10 ml fuel, tf sec 28 20 67
Manometer diff. --hw, cms. 1.2 0.7 0.3
Time for 1 lit, calorimeter water, sec. 70 70 70
Temperatures
Water inlet to Calorimeter T1 0C 24 30 30
Water outlet from Calorimeter T2 0C 59 45 50
Exhaust gas inlet to Calorimeter T3 0C 180 60 61
Exhaust gas outlet from Calorimeter T4 0C 174 51 55

20. Sr. No. 1 2 3
Brake Power (KW) 0.231 0.408 2.495
Fuel Consumption (kg/hr.) 2.52 1.26 0.9
Specific Fuel Consumption
(kg/kw hr.)
10.9 3.15 0.36
Heat Supplied by Fuel (KJ/hr.) 110602.9 55301.4 39501
Heat equivalent to BP (KJ/hr.) 831.6 4536 8982
Efficiency (%) 60 52 22
Air consumption 103.32 60.27 25.83
Mass flow air (kg/hr.) 24.2389 18.515 12.1195
Air fuel ratio 9.62 14.69 13.466
 CALCULATION TABLE

21.  ADVANTAGES
 Smaller/lighter
 Cheaper
 Less friction
 No oil to change
 Quicker acceleration
 Operate at different angles
simplified construction (no valves)
fire once every revolution for a significant power boost

22.  The engines do not last as long due to poor lubrication.
 You have to mix two cycle engine oil with gasoline.
 The engines do not use fuel efficiently.
 These engines produce a lot of pollution.
 DISADVANTAGES

23.  PRECAUTIONS
1. Check water supply and crankcase oil leave before starting the engine
2. 2% 2T oil must be added to petrol
3. Never stop the engine on load
4. For first some days of engine operation do not increase engine speed above
3500 rpm
5. Do not put hand in water rehostat while in operation
6. Do not close the orifice while engine is in operation
7. Add salt in water rheostat in correct percentage
8. After compilation of experiment drain all water