Intake manifold is an arrangement of tubing with several intake or outlet passages, through which a gas or liquid is gathered or distributed. The design of intake manifold has significant effect on engine performance characteristics. Volumetric efficiency is a quantitative comparison (typically expressed as a percentage) of physical cylinder volume to the volume of air entering in the cylinder at any given rpm. Current study was conducted to develop a spiral intake manifold model to predict gas flow in the intake system of a single cylinder internal combustion engine. Design of spiral intake manifold was altered with variable intake areas and the intake runners are bent around a common axis. The designed spiral intake manifold was fabricated using Additive Manufacturing (AM) technique. In this work, a Kriloskar single cylinder diesel engine has been used, which is coupled with tachometer and dynamometer. Generally, the intake manifold in use is a straight pipe through which air is sucked inside the engine. For the purpose of this study, the intake manifold was dismounted from the engine and the AM manufactured spiral intake manifold has been fitted. The spiral intake manifold was installed on the test rig and volumetric efficiency was calculated accordingly. Comparison is made with respect to volumetric efficiency using with and without using spiral intake manifolds. To conclude by using the spiral intake manifold, volumetric efficiency of the engine was enhanced at different injection pressures and varying loads.