Population growth and lifestyle changes have increased energy demand, while the availability of fossil fuels has decreased. This has led to the development of alternative energy sources, such as biodiesel fuel. Castor biodiesel is capable of being decomposed by biological processes, harmless, beneficial, and replenishable. The transesterification process can be utilized to generate biodiesel from castor oil, yield of production was 92% for the Transesterification. Mixing biodiesel castor with diesel positively affects its physical and chemical properties and also the running, exhaust pollutants, and combustion features, for performance BTE (Brake thermal efficiency) and BSFC (Brake specific fuel consumption). The biodiesel blend has higher BTE and lower BSFC than D100(pure diesel); it is D80TR20(80 vol% pure diesel + 20 vol% transesterification biodiesel), which gives an enhancement of 14.69% and 10%, respectively. Emissions like (CO, NOx, and soot) of biodiesel are better than those of D100; the D80TR20 emits lower emissions than the D100 by factors of 57%, 25%, and 28%, respectively. Also, the EGT(Exhaust gas temperature) of biodiesel is lower than D100, EGT of D80TR20 is lower than D100 than with a percentage equal to 9.76%, all of these values are with respect to D100 and at a load of 100%. It is recommended that the biodiesel blend is better than diesel and may be increasing of its ratio slightly, improving performance and emissions features more and more.