The purpose of this study is to simulate combustion, soot and NOx-emissions in the world's largest medium speed diesel V-engine, the W64V, based on simulation results of in line-engine W64L. The simulation tool was the modified KIVA2-CFD code to which the following submodels were added: The Magnussen EDC ( Eddy Dissipation Concept ) turbulent mixing combustion model, the extended Zeldovich NO model and a simple rebounding model for the droplet wall impingement. Further the Tesner&Magnussen soot formation and combustion model was implemented in the code and the modified TAB model was used for the spray.The simulation results, such as the cylinder pressure, the heat release rate and the cumulative heat release were compared with the results of a thermodynamic two zone model because the V-engine is under design and therefore measured quantities are not available. The correctness of the submodels was tested in the case of W64L engine by comparing the predicted cylinder pressure, the heat release and the cumulative heat release with the measured values of this engine.The simulation results show that the CFD combustion simulation tool works quite correctly for the W64L engine and further that this tool can quite safely to apply the power plant V-engine, the W64V. The simulations will reduce design expenses and time by decreasing the required trial and test work using a different construction.