This paper presents the comparison of combustion characteristics in a constant volume combustion chamber (CVCC) with alternative fuel biodiesel blends. To achieve this goal, a CVCC experimental was established, and the biodiesel was made from fish oil and was used as test fuel. The combustion process of diesel fuel (B0) and bio-diesel 10% (B10) will be investigated based on doing experiments with two conditions: air-fuel mixed before and after ignition timing. The influence of the oxygen concentration on the burning process is also being investigated. The results of the research show that the heat release rate of B0 is faster and higher than that of B10 in the case of air-fuel mixed before ignition timing. In the case of after ignition timing, these values are almost similar to B0 and B10.
