Saturday, 20 December 2014

Modification Effect of Volume Silinder Four Stroke Engine to Effective Power

By : Ir. Najamudin, MT
Lecturer of Mechanical Engineering,
Bandar Lampung University

International Conference on Engineering and Technology Development                   (3 rd ICETD 2014). 29 October 2014, Bandar Lampung, Indonesia

Modification Effect of Volume Silinder
Four  Stroke Engine to Effective  Power




Abstract: To improve the ability, power changes (performance) of a motor used for racing most mechanics do modifications to the cylinder volume. When the motor cylinder enlarged, the enlarged combustion volume, so that automatically will increase the compression ratio and compression pressure effect on the combustion pressure rise as well, in order to obtain great power. Bore up is a way to increase the volume of the contents of the cylinder, using a piston that has a larger diameter than the standard. So that the cylinder and piston are enlarged, the fuel and air for combustion in the engine can be more obtainable with high compression ratio that produces greater energy (torque) and a higher engine speed (rpm). In the discussion of this study the author discusses the influence of bore up the engine on the motorcycle supra x-cylinder 125 cc of cylinder diameter 52.4 mm to 54 mm, the things that need to be reviewed in this discussion include: Changes in power (performance), changes in torque before and after the engine in the bore up.
 Keywords : Bore up, power, torque, an increase in the volume of the cylinder.

Parts of Internal Combustion Engine
Figure 1. Parts of Internal Combustion Engine

Figure 2.Otto Cycle (Four Stroke Internal Combustion Engine )

The plunger (piston)
Piston which functions as a tool to suck the fuel, compress the fuel (compression), to accommodate the high-pressure power with higher temperatures. When the piston is replaced with a larger size, automatically measure the cylinder bore must be enlarged also in accordance with the relevant piston diameter and cylinder bore enlarging the term referred to the crankcase.

Figure 3. Cylinder and plunger (piston)

Volume of Cylinder
The total volume (Vt) obtained from the total volume of the piston stroke (V1) and clearence volume (VC). The volume of the piston stroke (V1) obtained from stroke piston is at TDC and BDC. Where large volumes of steps depending on the cylinder diameter (D) and the piston stroke length (L) usually has a unit cubic centimeters (cc). 
Figure 4. The volume of a cylinder


METHODS
Implementation Research
The study was performed using motorbike engines Supra X-125 cc and a standard that has been in the bore up (modified). This test focused on the comparison of the performance of the machines, which are obtained from the comparison between the standard engine with a cylinder diameter of 52.4 mm and  engine that already bore up (modified) with a 54 mm diameter cylinder.
This research is data taken power (power), the torque produced by the engine are not experienced and bore up the change and and a machine that already bore up (modified) with a 54 mm diameter cylinder at engine speed 1500, 2500, 4000, 5500 and 7000 rpm.

Tools and Materials
Tools and materials used in this experiment as follows:
  1. One unit of Honda Supra X-125 cc in 2006.
  2. The standard engine block units and one unit engine block that already bore up (modified) Honda Supra X-125cc.
  3. Dynojet, a tool used to calculate engine torque and maximum power is obtained at engine speed (rpm) specific.
  4. The fuel, in this case, or premium gasoline.
  5. Stop watch, to measure time in the experiment.
  6. Tachometer, to measure the rotation speed of the engine
  7. Feeler gauge, used to measure the valve gap and spark plug gap.
  8. Compression tester, used to measure the compression pressure in the cylinder.
Figure 5. The Cylinders and Pistons are used in testing
Implementation of the experiment
1. Experiment to standard machine conditions :

a. Measure the compression pressure on a standard machine conditions using Compression Tester, by installing a compression tester in the spark plug hole, then the machine at the kick starter a few times.
b. Open a faucet in the fuel line so that the carburetor filled.
c. Pressing the channel igniton switch to "on".
d. Turning the engine by means of a kick starter machine.
e. After the engine, adjust the throttle rev the engine to set up a stationary condition and then left to stand for 3-5 minutes to warm up.
f. After warming the engine for about 3-5 minutes, adjust / rotate the throttle so the initial rotation of 1500 rpm the engine and left for some time so that the rotation is stable.
g. Once the machine has been incited, new vehicles increased to Dynojet or dynotest.
h. At the same time, the data are read. Reading the magnitude of the torque, power or power at engine speed 2500 rpm.
i. Repeating steps i to round (n) = 4000 rpm.
j. The next step is the same as i. Every up 1 stroke, setting the addition of 1500 rpm engine rev up at 7000 rpm rotation and is also accompanied by the reading of the data.

2. Experiment for the condition of the engine that has been modified(bore up) :

a. Install the cylinder block dibore up on the vehicle.
b. After silnder block installed, then do the same test as the standard engine testing above.

c. When finished, operate the throttle control to the idle position round, then turn off the engine.





















Conclusion and Suggestion
Conclusion
Based on the results of research and analysis of data and discussion of the theory of the field is done, it can be concluded as follows:
1. In testing the power and torque of the engine to the standard conditions of cylinders 52.4 mm, 6.15 hp gain maximum power and maximum torque of 8.20 Nm using test equipment Dynojet.
2. Then in a test using a 54 mm cylinder power gain (power) 8.84 maximum hp and maximum torque of 10.01 Nm.
3. Specifications Engine before modified (bore up) :
     Stroke Volume (VL)                     = 124.8 cm3
     Clearence volume (Vc)                 = 15, 03 cm3
     Compression ratio (r)                   = 9.3: 1
     Maximum Effective Power          = 6.15 Hp
     Torque (T)                                                = 8.20 Nm
4. Specifications Engine after modified (bore up) :
     Stroke Volume (VL)                     = 132.54 cm3
     Clearence volume (Vc)                 = 15, 03 cm3
     Compression ratio (r)                   = 9.8: 1
     Maximum Effective Power          = 8.84 Hp
     Torque (T)                                                = 10.01 Nm
5. Judging from the analysis calculation upgrade the engine by means of a bore up stroke affect the volume, cylinder volume, power and greater torque than a standard machine conditions.

Suggestion
1. For motorcycle users who want to increase the power and speed of the bike can bore up the engine.
2. For the motorist who has experienced bore up the engine, you should change it ignition system and the fuel system in order to get a big power anyway.
3. It is recommended if you want to bore up, need to pay attention to the thickness of the cylinder wall, if it is too thin and followed the suggested enlarging the cylinder to replace the cylinder block as desired.

Please read more this article, brita.indo.com :
Ir. Najamudin, MT : Cara Menjadi Blogger yang Proffesional
Ir. Najamudin, MT: Evaluasi Prestasi Mesin Pada Turbin Uap (Steam Turbine)


Thanks

Ir. Najamudin, MT


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