the main motive behind this experimental setup was to find out the effect of temperature and droplet size on ignition delay period of different bio diesel blends. For experimental analysis, the equipment was assembled to carry out different tests for petroleum based Diesel and Bio-Diesel blends. During these tests, the Ignition delay of Diesel, Bio-Diesel and its different blends, in a temperature range of 600 °C to 750 °C and at an atmospheric pressure were studied. In addition fuel droplets of different diameters (750-950 microns) were introduced into the furnace chamber of the experimental set up and Combustion characteristics were measured for the Diesel and Bio-Diesel blends which shows the ignition delay time of diesel and BD blends decreases as the temperature increases. In this investigation, the effect of different combustion variables like the ignition temperature, ignition delay time, droplet diameter in the perspective of various biodiesel blends has been studied, and the effect of these variables on each other have been compared and elaborated in a simultaneous manner with the help of Design expert 3D graphs.