Abstract
In this paper the problem is discussed of supplying high power diesel engines with biofuels in the aspect of consequences which occurr during their operation. Attention was paid to advantages and difficulties associated with application of biofuels to self-ignition engines. A relevant research problem was characterized and research targets were proposed to make it possible to most favourably shape energy merits of the engines. Special attention was given to wear process of such engines and their failures resulting from application of biofuels. The following problems were also considered: calcium carbonate sedimentation, closing graphite platelets in structure of cylider bearing surface and surface defects of piston rings made of aluminium bronze. It was demonstrated that to assess operation of the engines is possible under the assumption that in a valuating approach their operation can be compared to a physical quantity represented numerically and measured with the use of the joule*sec unit. Conclusions resulting from the domestic and foreign investigations on power and reliability of such engines were also presented.