Abstract -In internal combustion engines valve events and timings are among the most important parameters which have a major influence on the volumetric efficiency and engine's performance. Variable valve timing (VVT) provides improvements in engine efficiency and performance by changing the valve lift and timing as a function of engine operating conditions. In this paper the obtained results by using the mathematical simulation pattern are presented by Simulating a VVT engine operation and load control through the inlet valve. Different degrees of Freedom for a variable intake profile such as variable intake duration and variable valve lift are considered and evaluated concerning their potential to optimize intake-lift profile for maximum volumetric efficiency over the whole engine speed range. Using camless valvetrain strategy, improvement in fuel economy as well as an increase in intake air charge is found throughout the engine map with the largest benefits arising from low speed operating conditions. The system offers a continuously variable and independent control of virtually all parameters of valve motion. This permits optimization of valve events for each operating condition without any compromise. In this paper we describe a phenomenological model for an unthrottled operation of a camless intake process in a spark-ignited (SI) engine. Initially the cylinder breathing dynamics is modeled and results are validated with experimental data of a conventional engine with a cam-driven valve profile during unthrottled operation. Then we determine the most optimized intake valve profile and timing in order to have the best volumetric efficiency and improved operation for each operating condition based on the existing model through numerical techniques.