1. LAB REPORT
INTERNAL COMBUSTION ENGINE
GROUP MEMBERS:
 AMEER NAWAZ (08-HITEC-ME-16)
 ALI RAZA (08-HITEC-ME-14)
 ARSLAN FAZIL (08-HITEC-ME-19)
SECTION: “C”
EXP : “05”
DATED : January 2012
SUBJECT:
Measurements of brake mean effective pressure and brake power of the engine.
.
SUBMITED TO:
SIR KAMRAN KAYANI.

2. APPARATUS:
 Diesel engine analyzer (4-stroke).
THEORY:
In this experiment we measured brake mean effective pressure and brake power of the diesel engine.
Speed of the engine was easily measured with the help of digital tachometer that is attached to the
computer. Brake power of the engine was calculated by dynamometer. We have a relation by which we
easily calculated brake mean effective pressure.
Where
Where
By relation we derived, we calculated brake mean effective pressure.
By increasing speed brake power of the engine increases because we set the torque constant so graph
between speed and brake power is linear. By increasing speed brake mean effective pressure first
increases but after certain level of speed it becomes low relatively to the previous.

3. PROCEDURE:
 First of all turn non engine analyzer.
 Then tachometer was turned on and air tank intake was properly checked.
 Then with coil starter start engine analyzer.
 Noted the reading from analyzing software in computer. At different speeds and
measured Brake power.
 Then calculate brake mean effective pressure.
TABLE:
Serial no. Speed Brake Power Brake Mean
Effective pressure
(rpm) (kwh) (bar)
1 1463 603 2.47
2 2093 1567 4.49
3 2880 2666 5.55
4 2938 2771 5.56
5 2945 2805 5.62
BRAKE POWER GRAPH:
3500
3000
2500
2000
1500 Brake Power
1000
500
0
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4. BRAKE MEAN EFFECTIVE PRESSURE:
500
450
400
350
300
250 Brake Mean Effective
200 pressure
150
100
50
0
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DISCUSSION AND CONCLUSIONS:
In this practical of internal combustion petrol engine lab it is observed that with the increase in speed the
break power of the engine go on increasing and continue to increase up till end, but in case of bmep, the
value of bmep increases with the increase in speed in start and this increase is quite significant but later
on, with further increase in speed will show a very less change or increase in the value of bmep and the
value of break mean effective pressure become almost constant.