Strict emission regulations and energy security concerns have led to various alternative concepts for the engine operation. Diesel–Methanol dual-fuel combustion solution has gained momentum over the past decade due to the fact that the technology required to convert a pure diesel engine to a dual-fuel one is mature, and methanol is a well-known substance in the industry. However, designing, tuning, and optimizing these engines require fast and reliable simulation models. For this purpose in the present study, a phenomenological combustion model, for a four-stroke port-injected methanol diesel engine, is established. The model is tuned with in-cylinder combustion data. The heat release rate is estimated via a triple-Wiebe function. Ignition delay is modeled with an Arrhenius-type expression, utilizing the methanol and diesel equivalence ratio, among other operational parameters. Other model parameters are obtained from data-driven functions, correlating the basic parameters of the combustion. The data used for model calibration and validation were generated with a computational fluid dynamic numerical model, and it was verified with data provided in the literature.