Direct simulation of the starting process of an electric machine using a three-dimensional (3D) transient finite element analysis (FEA) is very time-consuming. To overcome this difficulty, an interpolative finite element modeling of a large solid pole synchronous motor is presented and its starting process is simulated in this paper. In order to take into account the effects of cooling-ducts and end-turns, three different simplified 3D finite element models are proposed to reduce the computing time and save memory storage. With the proposed algorithm, an appropriate post-process is exploited to deduce an effective core length and an end-turn leakage inductance. Then a two-dimensional (2D) transient finite element model (FEM) with these modified parameters from 3D FEA is used to simulate the starting process. The proposed method is validated by the test results of a 15,000 hp, 13.2 kV, 4-pole solid pole synchronous motor.