Converting diesel engines to cheaper and cleaner fuels like LPG and CNG, with conventional methods needs a different combustion chamber, which has a lower compression ratio than a diesel engine (≻16:1) due to risk of detonation. This alteration makes the conversion process more expensive and difficult. On the other hand, decreasing a compression ratio leads to lower performance and efficiency compared to those of the original engine.To overcome this disadvantage it is proposed a novel mechanism for mixture formation and combustion, named as "MR-Process." This mechanism is realized in a combustion chamber MR-2 with twin-swirl turbulent flow. This chamber is suitable for operation with diesel fuels as well as with LPG and NG.In this paper are presented theoretical and experimental investigations of engines operating with "MR-Process" combustion mechanism.