As emissions standards become more stringent, OEMs are pushing engines to run on leaner fuel mixtures, which puts increased thermal stress on components, particularly pistons, causing them to operate at higher temperatures. This requires more robust design and rigorous testing of components. Telemetry methods offer accurate and real-time feedback, allowing designers to test components at various operating conditions, providing more flexibility than other traditional methods.
Piston temperature measurement is a critical aspect of engine development because it directly affects engine performance and durability. Among the various techniques available for this purpose, telemetry methods have gained considerable attention in recent years. This method involves integrating temperature sensors and transmitter on the piston, which transmit temperature data wirelessly to a receiver outside the engine.
In this paper, we evaluate the impact of coolant temperatures, valve timing, ignition timing etc. on piston temperature profile under various operating conditions, leveraging the flexibility of a telemetry system. Experiment was conducted on an In-Line 4-cylinder Natural aspirated Dual overhead camshaft (DOHC) bi-fuel engine equipped with a piston with six integrated temperature sensors along with transmitter for real-time temperature measurements. The test was performed on a Dynamometer bench and a Coolant Condition Unit (CCU) was used to vary the coolant temperature, while ignition timing, valve timing & Air-charge ratio was changed using INCA software (provided by ETAS Gmbh). The results demonstrate Linear correlation between Oil pressure and Piston temperature. While advance in ignition timing results in lower piston temperatures and vice-versa. Other parameters impact on piston temperature profile have also been discussed in this paper.