3.5. Engine tests
The Engine test were performed using water cooled Kirloskar
engine. The engine was run using pure diesel, B10, B20, B50 and
B100 fuels. From the experimental results of the engine tests using
these fuels, the following trends have been observed. Fig. 8 shows
the BSFC of diesel and other blends at different loads. It was
observed that BSFC decreased with increasing load. This was due
to the increase in the brake power of the engine at higher loads
[24]. The blends of biodiesel with conventional diesel have higher
BSFC when compared to pure diesel due to the differences in
calorific value. However, BSFC reaches a minimum value and then
slightly increases with further increase in engine loads with all
kinds of fuel [25]. This is due to the combined effects of the relative
density, viscosity and heating value of the blends. The higher density
of waste cooking oil based biodiesel leads to more discharge of
fuel for the same displacement of the plunger in the fuel injection
pump, thereby increasing the specific fuel consumption. In
addition, the engine also might have become overheated beyond
a certain load and hence a sharp increase in the BSFC value [25].
Thus this trend is due to the combined effects of the relative fuel
density, viscosity and heating value of the blends.