Wankel rotary engines are found to be useful in unmanned aerial vehicles, powered hang gliders, loitering munition, and other strategic applications. They are also promising candidates for hybrid power trains, due to their high power-to-weight ratio. CSIR-NAL has indigenously developed Wankel engines with different power ratings, such as 65, 55, and 30 hp. Out of these, 30 hp is an air-cooled and single-rotor engine. A detailed study has been undertaken to create a health management framework for this engine. Several parameters, including vibration, temperature, etc., are monitored for health and performance assessment. Typically, compared to their nearest sibling, reciprocating IC engines, Wankel engines have less vibration due to their rotary nature. However, continuous monitoring and trend analysis of vibration data becomes essential to assess the health of the rotating components of the engine. Experimental data was collected during ground testing following specified endurance test cycles. This paper describes the vibration trend monitoring adopted for the 30-hp class Wankel engine. In total, twenty-one frequencies were identified, and variations in amplitude over the period were tracked along with their harmonics. During the testing, all the rotating components were labelled to be healthy based on the established trend. This analysis will help to establish engine endurance and time between overhauls of the indigenous Wankel engine.