One-dimensional models for internal combustion engines analysis are very useful to simulate its systems through a relatively low computational effort. Based on this idea, this paper presents the simulation of a spark-ignition engine using one-dimensional models implemented in object oriented programming by the authors.The model was adapted to simulate a research four valves, single cylinder, spark ignition, reciprocating internal combustion engine. The gas in the cylinder was described by conservation equations, including the momentum conservation equation, that wasn’t found in the checked literature. For the combustion, a two zones model was implemented, based on combustion wave equations, such that detonation and deflagration are calculated by the same set of equations. The flame propagation geometry was considered to be spherical. The numerical and experimental data to the engine working with commercial ethanol were compared in order to evaluate the quality of the model, which included the analysis of the pressure, temperature, mean effective pressure, apparent heat release, mass burnt fraction, among other aspects. They presented good agreement, showing an interesting potential for the software and some other points which could be refined in the future to make the software even more reliable and practical.