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Developing and designing fuel efficient vehicle for a one gallon of fuel marathon is a challenging task. Engines have to be optimized to achieve maximum fuel efficiency. In this study, we evaluate the optimal compression ratio (CR) and ignition timing that produce the best torque in a custom gasoline-based-motorcycle-engine that use ethanol E100 fuel. In the first experiment, CR was adjusted between 9 and 12 to evaluate its effect on the engine mileage’s record. The experiment was conducted on the test track. In the second experiment, Ignition timing was adjusted by a custom-made engine control unit (ECU) between 15° and 45° before top dead center (BTDC). The engine performance was investigated in terms of best torque and brake specific fuel consumption (BSFC), with variation of engine speed between 1500 and 8000. The test was conducted on dynamometer. The test was also performed in constant compression ratio and stoichiometric air-fuel ratio, 9.

The operation of Diesel engines now days has demanded higher thermal efficiency and lower emission to achieve low cost operation and to comply emission regulation. It is well known that the start of combustion will decide the quality of combustion. The start of combustion can be used to analyze the injection process and also the combustion process. In this work, wavelet analysis is used to determine the start of combustion will be discussed in this paper. The common method to determine the start of combustion is normally using the second order derivation of combustion chamber pressure. This method is used to validate the results from wavelet analysis. The experiments are conducted using several types of Diesel engines operated in several operating conditions. The results show consistently coincidence between start of combustion determined from pressure transducer and determined from the wavelet analysis in any rpm and load.

Through the progress of science and proven technology, the automotive industry has reached a remarkable potential to manufacture and develop fuel efficient cars, utilizing new fuels and new materials, with low exhaust gas emission, all of which constitute safe and friendly vehicles. The development of the automotive industry in Indonesia stimulates innovation and a desire to design.

A noise analysis based on coherence method has been developed and utilized as a diag - nostic tool for defect detection of a gear box. A case study has been carried out on a multiple reduction gear box and the emitted noise is measured during normal working environment thus the signals are subjected to external disturbing noise. Using the coherence method, the original signals are identified and further analysis is carried out using enhanced Campbell as well as Order-ratio diagrams. The results show that the coherence method is a powerful tool in noise analysis.

This paper presents the test results of a research on the use of a detergent additive in gasoline. The main objective was to find out the additive effect on carburettor cleanliness and gasoline consumption. To show this additive effect, three pairs of vehicles of different makes and types were subjected to controlled test on the roads in a fixed route and on the chassis dynamometer at two different constant speeds. Additional tests on a monocylinder engine, each time kept in the same operational conditions for comparison tests, were conducted to show the additive effect in a thermodynamic sense (if there are any). The test distance travelled by each vehicle during the whole test was approx. 10,300 KM The average time needed was approx. 314 hrs. with an average speed of approx. 33 KM/hr. The average fuel consumption for each vehicle was approximately 1,170 litre, while the average fuel saving was approximately 7%. The monocylinder test results were impartial.

Moving vehicle is excited by road waviness. The random dynamic vehicle response is analysed by using frequency analysis. The vehicle transfer function is calculated by using component element method and the random road waviness is characterized by its power spectral density. The power spectral density of several road types in West Java has been measured. Using the measured road power spectral density and the calculated vehicle transfer function, the vehicle responses are analysed. Using this analysis, the vehicle suspension parameters can be found to meet better vehicle running quality.

An experimental study has been carried out on a transmission system which consists of a pair of spur gears mounted using ball bearings on a steel frame and rotated by a frequency controlled A-C electromotor. The vibration sources among the rotating components of the system have been investigated using Campbell diagram technique and its influence on the frequency spectrum at the measuring points located on the frame has been identified. Harmonic as well as random excitation techniques have been conducted to reveal the transfer-function and the frequency spectrum at those measuring points. It is observed, for low frequency range (up to 125 Hz) similar transfer functions are obtained through out the measuring points. On the other hand for high frequency (above 125 Hz) the transfer functions are significantly influenced by the local propagation path.

The higher thermal efficiency of diesel engine over gasoline engine has been known. Recent developments show that more and more compact diesel engines come into the market. Therefore, diesel engines will not only be used for trucks and buses, but also for jeeps and passenger cars. However, concerning the increasing demand of diesel engines in the automotive field, the fuel availability must be considered as one of the very important parameters for engine selection. In the paper the basic consideration will be put forward and the methodology will be developed so that alternative soluctions can be shown.

The International Pacific Conference on Automotive Engineering may be viewed as reflecting the results of concerted and cooperative efforts and should be noted in the annals of the development of professional organizations. It represents a very encouraging event because it obviously reflects a spirit of friendship and provides excellent opportunity for getting acquainted. Many challenges are to be faced by automotive engineers, researchers, and designers.