Development of a method for assessing the condition of spark-ignition internal combustion engines based on starter cranking current

BACKGROUND: Significant strides are being made in the development of conventional spark-ignition internal combustion engines (SI ICEs), especially with the advent of electric vehicles. However, this leads to an increase in the cost of unit repair due to the emergence of more complex designs, which also require more meticulous condition monitoring. The scientific novelty of the research lies in the development of an engine diagnostic method that requires neither disassembly nor significant intervention into the engine’s structure or its ancillary components. AIM: Development of a method for assessing the condition of a spark-ignition internal combustion engine (SI ICE) based on the starter cranking current, proposing its implementation in a mass-produced vehicle. METHODS: An analysis and evaluation of existing ICE diagnostic methods from open sources was conducted. Based on this analysis, a formula that accounts for the design features of SI ICEs and starters is presented. A series of experimental studies were also carried out to verify the adequacy of the mathematical formula. The mathematical model was adapted based on the data obtained from the experiments. The formula for the calculated relationship was embodied in an xlsx file in Microsoft Office Excel. The method’s algorithm based on the acquired mathematical and experimental data was developed. Based on the interim results, the method was developed and the technique for its implementation on a series-production vehicle was proposed. RESULTS: A correlation between compression values and starter motor inrush current values was established. Experimental studies were conducted on a mass-produced vehicle. The results were obtained using a mathematical formula. A comparison of experimental and calculated data was carried out. CONCLUSION: The developed method for assessing the condition of spark-ignition internal combustion engine has practical value which lies in the potential for implementing this method in a mass-produced vehicle.