The Engine cylinder is one of the major automobile components, which is subjected to high temperature variations and thermal stresses. In order to cool the cylinder, fins are provided on the surface of the cylinder to increase the rate of heat transfer. By doing thermal analysis on the engine cylinder fins, it is helpful to know the heat dissipation inside the cylinder. We know that, by increasing the surface area we can increase the heat dissipation rate. The main aim of the present paper is to analyze the thermal properties by varying geometry, material of cylinder fins using Ansys work bench. Transient thermal analysis determines temperatures and other thermal quantities that vary over time. The variation of temperature distribution over time is of interest in many applications such as in cooling. The accurate thermal simulation could permit critical design parameters to be identified for improved life. Presently Material used for manufacturing fin body is Cast Iron. In this thesis, it is replaced by various types of aluminum alloys. By observing the analysis results, total heat flux is more for aluminum alloys than remaining cast iron, magnesium alloy materials for both condenser and evaporator. So aluminum alloy would be better for cylindrical fins.