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This paper presents experimental test results of a diesel engine using additive added bio Diesel oil obtained from palm oil. The test results obtained are brake power, specific fuel consumption (SFC) and exhaust emissions. In addition, anti-wear characteristics of fuel's contaminated lubricants were observed using a tribometer test. A computer control dynamometer-engine test bed was used to measure engine brake power and SFC at half throttle condition with speed range of 1000 rpm to 4000 rpm. The emission test was done with dynamometer fixed load of 50 Nm and constant engine speed of 2250 rpm. A total of three fuels or 100% diesel fuel (B0); 20% palm oil diesel (POD) and 80% B0 (B20); and B20 with X% additive (B20X) were selected for this investigation. The B20X is the additive added bio Diesel oil where X is the percentage (in this investigation X=1% of B20) of additive in B20 fuel.

Nowadays, engine problems such as higher NOx, increase in smoke content and low brake power output due to biofuel fueled engine have been reduced by several improvements by using additives or modifications on engine itself. This paper presents a type of compositions and proper combination of selected chemical components which may be used in palm olein-diesel blends namely “Envo-Diesel”. The blended component was designed as an additive package which was blended with diesel-biofuel at 99:1 up to 95:5 percent ratios. Blended fuels with additive have been used in the single cylinder engine which operated under 2000 rpm for 100 hours. Engine performance and emissions tests were conducted as well as engine deposit analysis was done after 100 hours engine operation time.

This paper presents experimental test results of a new compressed natural gas direct injection (CNG-DI) engine that has been developed from modification of a multi cylinder gasoline port injection (PI) engine. The major modifications done are (1) the injection system has been modified to gas direct injection using new high pressure gas injectors, (2) compression ratio has been changed from 10 to 14 through modification of piston and cylinder head, and (3) new spark plugs with long edge were used to ignite the CNG fuel. The CNG pressure at common rail was kept at 20 bar to be injected into engine cylinder. The engine has been operated with full throttle conditions to compare all the results with original base engine such as gasoline port injection engine and the CNG bi-fuel engine where the base engine has been converted to bi-fuel injection system to be operated with gasoline and CNG fuels.

Air-fuel ratio (AFR) is a crucial parameter for combustion controls in internal combustion engines. An incorrect AFR metering for reciprocating internal combustion engine causes high toxic gases emissions formulation, serious fuel consumption problems and unbearable combustion noise and combustion deterioration. Traditionally, the AFR is obtained by direct measurement of intake air and the fuel either injected into the combustion chamber or pre-mixed at the carburetor. However, the accurate AFR obtained from direct measurement is difficult due to measuring equipments resolution prone to errors. This paper describes a method for accurate determination of air-fuel ratio based on exhaust emission gas analysis as an additional tool used to be validated the conventional direct air fuel flow rates measurement.

This paper presents the results of an experimental work carried out to evaluate the combustion and emission characteristics of ordinary coconut oil (COIL) blended fuel on unmodified indirect injection (IDI) diesel engine. Diesel fuel (DF2) was used for comparison purposes. The test results on coconut oil blended fuel showed that the addition of up to 30% coconut oil with DF2 has significantly increased brake power and net heat release rate with a net reduction in exhaust emissions such as HC, NOx, CO, smoke and poly-cyclic aromatic hydrocarbons (PAH). This means that COIL blended fuel has similar ignition quality as DF2, and indeed better combustion. However, COIL blended fuel increases specific fuel consumption due to higher specific density of coconut oil. When more than 30% of coconut oil is added (40% - 50%), the brake power produced and the net heat release rate are slightly less due to low internal energy, but better combustion still takes place.