Journal of Mechanical Engineering Science and Technology ISSN 2580-0817
Vol. 6, No. 1, July 2022, pp. 48-55 48
DOI: 10.17977/um016v6i12022p048
Gasohol Engine Performance with Various Ignition Timing
Hendry Y. Nanlohy1*, Suyatno1, Helen Riupassa1, Marthina Mini1, Trismawati2,
Mebin Panithasan3
1Department of Mechanical Engineering, Jayapura University of Science and Technology,
Jayapura, 99351, Indonesia
2Department of Industrial Engineering, Panca Marga University, Probolinggo, 67271, Indonesia
3Department of Mechanical Engineering, King Abdullah University of Science and Technology,
23955, Saudi Arabia
*Corresponding author:hynanlohy@gmail.com
Article history:
Received: 11 June 2022 / Received in revised form: 25 June 2022 / Accepted: 29 June 2022
ABSTRACT
Experimental research has been conducted on the effect of ignition timings on the characteristics and
performance of gasohol engines such as power, torque, specific fuel consumption, and thermal efficiency.
The fuel used in this research is pure gasoline and a mixture of 50% bioethanol (BE50). The results show
that the ignition timing that gives the maximum effect occurs at the top and bottom dead points of 9 degrees
for gasoline and 12 degrees for BE50 fuel. Furthermore, the maximum power is obtained at 6,500 rpm, and
at an ignition time of 12 degrees BTDC the maximum power generated is 4.63 hp, while for an ignition time
of 9 degrees BTDC the power generated is 3.38 hp which occurs at 6500 rpm. These results indicate that
there is an increase in power of 6.4%. Moreover, the results also show that for optimal gasoline conditions,
the amount of energy consumed at an engine speed of 7000 rpm is around 15705.78 kcal/hour, and for BE-
50 it is around 12582.03 kcal/hour, where there is a reduction of about 25.44 %. However, in general, it can
be seen that during optimal ignition, there is a saving in fuel consumption in the gasoline-BE50 mixture,
while at the same time producing a fairly large thermal efficiency. These results indicate that BE50 has the
potential to be used as an alternative fuel in small gasoline engines.
Copyright © 2022. Journal of Mechanical Engineering Science and Technology.
Keywords: Bioethanol, engine power, fuel consumption, ignition timing, thermal efficiency, torque
I. Introduction
The increase in industrial activity and the increasing world population cause fuel
consumption to increase so that it interferes with air quality and causes an energy crisis [1],
[2]–[4]. This makes the need for environmentally friendly alternative fuels very crucial [3],
[5]. Therefore, the researchers conducted many studies and found that bioethanol is one type
of alternative fuel that can be applied to internal combustion engines (ICdisE) and at the
same time to overcome the fuel energy crisis [4], [6], [7]. The raw material for bioethanol
used in this study is sourced from coconut sap water which is processed through natural
fermentation and fractional distillation [8], [9]. Furthermore, the production cost is relatively
cheap because it only requires distillation equipment, unlike the transesterification or
esterification process which is more expensive and need more equipment. Moreover, it
requires a long process with a lot of equipment.Bioethanol is one type of alternative fuel that
is converted from bioenergy plants and biomass [10], and with a high octane number, it has
the opportunity to be used as an alternative to gasoline [11]. In addition, bioethanol has
49 Journal of Mechanical Engineering Science and Technology ISSN 2580-0817
Vol. 6, No. 1, July 2022, pp. 48-55
Nanlohy et al. (Gasohol Engine Performance with Various Ignition Timing)
greenhouse gas emissions and lower production costs, as well as a more profitable future
evolution that makes bioethanol and its mixtures have great potential to be used as renewable
fuels, especially in ICE [12]. On the other hand, a lot of research has been done on the
production of bioethanol and its application to machinery [13], [14] and it was found that
ethanol fuel is suitable for internal combustion engines but is more focused on diesel engines
[15]–[17]. In addition, a recent study on the effect of a mixture of ethanol and gasoline on
NOx emissions [18] and their effect on fuel properties and fuel efficiency for blending
ethanol and gasoline have also been applied to the ICE and resulted in very good
performance improvements [8], [19].
On the other hand, studies on the application of bioethanol (BE5, BE10, BE15, and
BE20) by modifying the ignition timing constant on the ICE have been carried out [20].
From the results of the study, it was found that there was an increase in the octane number
for all variations of gasoline bioethanol mixtures and reduced carbon monoxide and
unburned hydrocarbon gas emissions. Furthermore, for BE30 with different ignition timing
variations, it was also found that emission reduction achieved by increasing the ignition
timing further advanced the ignition timing resulting in a significant reduction in NOx
emissions [21], [22].
However, it is unfortunate because there are no results from the above research that
have revealed the effect of the use of a mixture of bioethanol and gasoline on a stationary SI
engine including combustion characteristics, performance, and exhaust emissions.
Therefore, this study aims to reveal scientific information about the performance of
bioethanol fuel and its mixture with gasoline on the performance of stationary ICE, including
power, torque, SFC, and thermal efficiency (ηth).
II. Material and Methods
This study uses pure gasoline and a mixture of gasoline with 50% Bioethanol (BE50).
The results of testing the fuel properties can be seen in Table 1.
Table 1. Comparison of the main properties of fuel
Properties Gasoline BE-50
Molecular formula C7H18 C2H5OH
Molecular weight 100-105 46.07
Research octane number (RON) 95.5 120-135
Auto-ignition temperature (oC) 257 423
Specific heat (kJ/kg K) 2.4 2.0
Density at 15 oC (g/ml ) 0.739 0.79
Viskosity at 20 oC (mPa) 1.19 0.37-0.44
In addition, this experiment used a variable speed test with a wide-open throttle
accompanied by a load setting on the water brake dynamometer to get the expected engine
speed [10]. The research scheme can be seen in Figure 1. The test begins with checking the
engine performance on the ignition timing BTDC 9 degrees, 12 degrees, and 15 degrees.
The engine is operated with an engine speed of 4000 rpm to 7500 rpm accompanied by
cooling from the fan to avoid overheating. The next step is to increase the engine speed until
a half-open throttle condition is achieved accompanied by loading by adjusting the water
ISSN: 2580-0817 Journal of Mechanical Engineering Science and Technology 50
Vol. 6, No. 1, July 2022, pp. 48-55
Nanlohy et al. (Gasohol Engine Performance with Various Ignition Timing)
flow opening through the water brake dynamometer to 7500 rpm and then observing the
load (N) and time (s). The first test used pure gasoline and after that, it used a BE50 mixture
where the combustion time was increased every 3 degrees.
Fig 1. Experimental scheme
III. Results and Discussions
A study on the comparison of the effect of gasoline-BE50 mixture and variations in
ignition timing on the performance of the ICE has been carried out. The results showed that
there were changes in engine performance parameters, including; torque, effective engine
power, thermal efficiency (ηth), specific fuel consumption, and energy consumption.
Fig 2. Comparison of torque (left) and engine power (right)
Figure 2 shows the maximum torque achieved at 12 degrees BTDC ignition time is 6.05
N.m and for 9 degrees BTDC ignition timing is 5.93 N.m, and these results indicate that
there is an increase in torque of 1.97%. Meanwhile, when compared to gasoline, there was
a decrease in torque from 6.93 N.m to 6.05 N.m, or an average decrease of 7.54%. These
results indicate that more bioethanol content in gasoline causes a decrease in power. This
analysis is possible because the specific energy and heat (see Table 1) contained in the BE50
fuel mixture are very low. Furthermore, the large hydrogen mass content in bioethanol has
51 Journal of Mechanical Engineering Science and Technology ISSN 2580-0817
Vol. 6, No. 1, July 2022, pp. 48-55
Nanlohy et al. (Gasohol Engine Performance with Various Ignition Timing)
the potential to increase the strong attractive force with oxygen so that it has the potential to
produce H2O molecules and become a coolant in the combustion chamber. This is very
reasonable because from Figure 2 it can be seen that the maximum power is obtained at
6,500 rpm, and at an ignition time of 12 degrees BTDC the maximum power generated is
4.63 hp, while for an ignition time of 9 degrees BTDC the power generated is 3.38 hp which
occurs at 6500 rpm. These results indicate that there is an increase in power of 6.4%. On the
other hand, when compared to the power produced by gasoline under standard conditions,
there is a decrease in power from 4.86 hp to 4.63 hp, or an average decrease of 7.55%.
Fig 3. Variations in thermal efficiency (left) and specific fuel consumption (right) at different
engine speeds
On the other hand, thermal efficiency is a parameter of the amount of energy used in
the converted fuel to produce optimal work (N). Figure 3 shows that the highest thermal
efficiency is obtained at 9 degrees, while the smallest is at 15 degrees. This result proves a
phenomenon where the spraying of fuel into the combustion chamber at an ignition time of
9 degrees BTDC becomes more effective for generating power. This is very possible
because, during the compression process and the ignition timing just before reaching the top
dead point, the mass of material that can react in the combustion stage becomes less. This
result is confirmed and indicated by the amount of specific fuel consumption with a low
ignition timing of 9 degrees.
In addition, Figure 3 (right) also shows that the lowest SFC occurs at the ignition timing
of 9 degrees when compared to fuel consumption at other positions. This is what causes the
thermal efficiency to be greater. In addition, the results of the study also found that the
maximum thermal efficiency was achieved at an ignition timing of 12 degrees BTDC
accompanied by the maximum power generated (see Figure 4). While the minimum thermal
efficiency is at 9 degrees BTDC ignition time. On the other hand, it can be seen that although
the ignition time of 9 degrees BTDC is less than that of gasoline, the BE-50 has the highest
thermal efficiency. This phenomenon is influenced by the lower calorific value of BE50
which is around 8427.86 kcal/kg so that energy consumption with BE50 is reduced.
Moreover, this indicates that at the correct ignition timing, the air-fuel ratio is achieved, and
this is triggered by the increased reactivity of the many hydrogen atoms in bioethanol. This
analysis is very possible and is by previous research which states that atomic reactivity has
the potential to increase the reaction speed of the fuel molecules to increase the energy
contained in the fuel [23], [24].
19
20
21
22
23
24
25
26
27
3500 4500 5500 6500 7500 8500
T
h
e
rm
a
l e
ff
ic
ie
n
cy
(
%
)
Engine speed (rpm)
09 BTDC
12 BTDC
15 BTDC
0.240
0.260
0.280
0.300
0.320
0.340
0.360
3500 4500 5500 6500 7500 8500
S
fc
(
kg
/h
p
ja
m
)
Engine speed (rpm)
09 BTDC
12 BTDC
15 BTDC
ISSN: 2580-0817 Journal of Mechanical Engineering Science and Technology 52
Vol. 6, No. 1, July 2022, pp. 48-55
Nanlohy et al. (Gasohol Engine Performance with Various Ignition Timing)
On the other hand, from Figure 4 it can be seen the impact of changing the ignition
timing on the amount of energy consumed (EC). For optimal gasoline conditions, the amount
of energy consumed at engine speed of 7000 rpm is around 15705.78 kcal/hour, and for BE-
50 it is around 12582.03 kcal/hour, where there is a reduction of about 25.44%.
Fig 4. Comparison of thermal efficiency (left) and energy consumption (right) at different
engine speeds
IV. Conclusions
An analysis of the effect of ignition timing of various degrees on the performance of
gasoline-bioethanol-fueled gasoline engines has been carried out, and there are some very
important practical findings. The optimal ignition timing for gasoline engines is 9 degrees,
while for bioethanol the optimal ignition timing is 12 degrees BTDC. Furthermore, the
improved performance of the BE50-petrol mixed fuel engine proves that the BE50 can be
used as an alternative fuel by changing the ignition timing. As for the BE-50, the ignition
timing must be changed to 12 degrees BTDC where the skepticism needle in the carburetor
is in position one from the bottom to produce an optimal power of 4.63 HP at 6500 rpm, and
an optimal torque of 6.05 Nm at 4000 rpm.
To get the maximum benefit from bioethanol, further research is needed using
bioethanol with a higher blend content of 80 to 95% bioethanol (BE80-BE95) or 100%
bioethanol (BE100) on SI engines with engine speeds of around 5000 to 8000 rpm. Several
studies have found that without modification [25], the bioethanol-fueled SI engine produces
different performance [26], so it can be tried to modify the engine with different loading and
compression ratio variations.
Acknowledgment
A big thank you to LPPM Jayapura University of Science and Technology for their
financial assistance and support so that this research can be completed properly. In addition,
thanks also to the Fuel and Combustion Laboratory, Department of Mechanical Engineering,
Jayapura University of Science and Technology for the support of research materials and
equipment.
53 Journal of Mechanical Engineering Science and Technology ISSN 2580-0817
Vol. 6, No. 1, July 2022, pp. 48-55
Nanlohy et al. (Gasohol Engine Performance with Various Ignition Timing)
References
[1] H. Y. Nanlohy, “Performance and Emissions Analysis of BE85-Gasoline Blends on
Spark Ignition Engine,” Automot. Exp., vol. 5, no. 1, pp. 40–48, 2022, doi:
https://doi.org/10316/ae.6116.
[2] M. A. Aktar, M. M. Alam, and A. Q. Al-Amin, “Global economic crisis, energy use,
CO2 emissions, and policy roadmap amid COVID-19,” Sustain. Prod. Consum., vol.
26, pp. 770–781, 2021, doi: 10.1016/j.spc.2020.12.029.
[3] D. Londoño-Pulgarin, G. Cardona-Montoya, J. C. Restrepo, and F. Muñoz-Leiva,
“Fossil or bioenergy? Global fuel market trends,” Renew. Sustain. Energy Rev., vol.
143, February 2021, doi: 10.1016/j.rser.2021.110905.
[4] B. Sayin Kul and M. Ciniviz, “An evaluation based on energy and exergy analyses in
SI engine fueled with waste bread bioethanol-gasoline blends,” Fuel, vol. 286, no.
P2, p. 119375, 2021, doi: 10.1016/j.fuel.2020.119375.
[5] S. Adams, F. Adedoyin, E. Olaniran, and F. V. Bekun, “Energy consumption,
economic policy uncertainty and carbon emissions; causality evidence from resource
rich economies,” Econ. Anal. Policy, vol. 68, pp. 179–190, 2020, doi:
10.1016/j.eap.2020.09.012.
[6] M. Göktaş, M. Kemal Balki, C. Sayin, and M. Canakci, “An evaluation of the use of
alcohol fuels in SI engines in terms of performance, emission and combustion
characteristics: A review,” Fuel, vol. 286, July 2020, 2021, doi:
10.1016/j.fuel.2020.119425.
[7] O. I. Awad, R. Mamat, and O. M. Ali, “Alcohol and ether as alternative fuels in spark
ignition engine: A review,” Renew. Sustain. Energy Rev., vol. 82, pp. 2586–2605,
September 2018, doi: 10.1016/j.rser.2017.09.074.
[8] H. Y. Nanlohy, “Perbandingan Variasi Derajat Pengapian Terhadap Efisiensi
Thermal Dan Konsumsi Bahan Bakar Otto Engine BE50,” Dinamika, vol. 3, no. 2,
pp. 1–4, 2012, doi:10.33772/djitm.v3i2.289.
[9] H. Y. Nanlohy, S. Adiwidodo, M.Yamaguchi, R. Subagyo et al., “The Use of
Bioethanol-Isooctane Blend and the Effect of its Molecular Properties on Si Engine
Performance and Exhaust Emissions,” SSRN Electron. J., 2022, doi:
10.2139/ssrn.4097552.
[10] M. Nibin, J. B. Raj, and V. E. Geo, “Experimental studies to improve the
performance, emission and combustion characteristics of wheat germ oil fuelled CI
engine using bioethanol injection in PCCI mode,” Fuel, vol. 285, p. 119196, 2021,
doi: 10.1016/j.fuel.2020.119196.
[11] S. M. Sarathy, A. Farooq, and G. T. Kalghatgi, “Recent progress in gasoline surrogate
fuels,” Prog. Energy Combust. Sci., vol. 65, pp. 67–108, 2018, doi:
10.1016/j.pecs.2017.09.004.
[12] M. K. Mohammed, H. H. Balla, Z. M. H. Al-Dulaimi, Z. S. Kareem, and M. S. Al-
Zuhairy, “Effect of ethanol-gasoline blends on SI engine performance and
emissions,” Case Stud. Therm. Eng., vol. 25, p. 100891, 2021, doi:
10.1016/j.csite.2021.100891.
[13] H. Taghavifar, B. K. Kaleji, and J. Kheyrollahi, “Application of composite TNA
ISSN: 2580-0817 Journal of Mechanical Engineering Science and Technology 54
Vol. 6, No. 1, July 2022, pp. 48-55
Nanlohy et al. (Gasohol Engine Performance with Various Ignition Timing)
nanoparticle with bio-ethanol blend on gasoline fueled SI engine at different lambda
ratios,” Fuel, vol. 277, p. 118218, May 2020, doi: 10.1016/j.fuel.2020.118218.
[14] B. Sayin Kul and M. Ciniviz, “Assessment of waste bread bioethanol-gasoline blends
in respect to combustion analysis, engine performance and exhaust emissions of a SI
engine,” Fuel, vol. 277, p. 118237, 2020, doi: 10.1016/j.fuel.2020.118237.
[15] Z. Guo, X. Yu, and Dong, “Research on the combustion and emissions of an SI engine
with acetone-butanol-ethanol (ABE) port injection plus gasoline direct injection,”
Fuel, vol. 267, p. 117311, February 2020, doi: 10.1016/j.fuel.2020.117311.
[16] A. K. Thakur, A. K. Kaviti, R. Mehra, and K. K. S. Mer, “Progress in performance
analysis of ethanol-gasoline blends on SI engine,” Renew. Sustain. Energy Rev., vol.
69, pp. 324–340, 2017, doi: 10.1016/j.rser.2016.11.056.
[17] G. Liu, C. Ruan, Z. Li, G. Huang et al., “Investigation of engine performance for
alcohol/kerosene blends as in spark-ignition aviation piston engine,” Appl. Energy,
vol. 268, p. 114959, 2020, doi: 10.1016/j.apenergy.2020.114959.
[18] M. N. A. M. Yusoff, N.W.M. Zulkiflia, H.H. Masjukia, M.H. Harith et al.,
“Comparative assessment of ethanol and isobutanol addition in gasoline on engine
performance and exhaust emissions,” J. Clean. Prod., vol. 190, pp. 483–495, 2018,
doi: 10.1016/j.jclepro.2018.04.183.
[19] P. Chansauria and R. K. Mandloi, “Effects of Ethanol Blends on Performance of
Spark Ignition Engine-A Review,” Mater. Today Proc., vol. 5, no. 2, pp. 4066–4077,
2018, doi: 10.1016/j.matpr.2017.11.668.
[20] D. Y. Dhande, N. Sinaga, and K. B. Dahe, “Study on combustion, performance and
exhaust emissions of bioethanol-gasoline blended spark ignition engine,” Heliyon,
vol. 7, no. 3, p. e06380, 2021, doi: 10.1016/j.heliyon.2021.e06380.
[21] T. Su, C. Ji, S. Wang, L. Shi, and X. Cong, “E ff ect of ignition timing on performance
of a hydrogen-enriched n-butanol rotary engine at lean condition,” Energy Convers.
Manag., vol. 161, pp. 27–34, 2018, doi: 10.1016/j.enconman.2018.01.072.
[22] Y. Şöhret, H. Gürbüz, İ. H. Akçay, “Energy and exergy analyses of a hydrogen fueled
SI engine : Effect of ignition timing and compression ratio,” Energy, vol. 175, pp.
410–422, 2019, doi: 10.1016/j.energy.2019.03.091.
[23] H. Y. Nanlohy, I. N. G. Wardana, N. Hamidi, L. Yuliati, and T. Ueda, “The effect of
Rh3+ catalyst on the combustion characteristics of crude vegetable oil droplets,” Fuel,
vol. 220, 2018, doi: 10.1016/j.fuel.2018.02.001.
[24] H. Y. Nanlohy, I. N. G. Wardana, M. Yamaguchi, and T. Ueda, “The role of rhodium
sulfate on the bond angles of triglyceride molecules and their effect on the combustion
characteristics of crude jatropha oil droplets,” Fuel, vol. 279, p. 118373, Nov. 2020,
doi: 10.1016/J.FUEL.2020.118373.
[25] S. Shirvani, S. Shirvani, A. H. Shamekhi, and R. D. Reitz, “A study of using E10 and
E85 under direct dual fuel stratification (DDFS) strategy: Exploring the effects of the
reactivity-stratification and diffusion-limited injection on emissions and performance
in an E10/diesel DDFS engine,” Fuel, vol. 275, p. 117870, April 2020, doi:
10.1016/j.fuel.2020.117870.
55 Journal of Mechanical Engineering Science and Technology ISSN 2580-0817
Vol. 6, No. 1, July 2022, pp. 48-55
Nanlohy et al. (Gasohol Engine Performance with Various Ignition Timing)
[26] J. R. Varma, S. K. R. Katepalli, M. Sreeja, and B. Hadagali, “Comprehensive studies
on alcohol using port fuel injection facilitated with spark plug engine,” Mater. Today
Proc., vol. 45, pp. 3219–3225, 2021, doi: 10.1016/j.matpr.2020.12.379.