Final answer:
The question pertains to engine restart limitations concerning time, EGT, and N2. While the reference mentions specific temperatures, it lacks precise restart guidelines. Generally, manufacturers provide clear restart limits to prevent engine damage, focusing on EGT thresholds and cooldown times.
Step-by-step explanation:
The question addresses the concern regarding the limitations for restarting an engine, specifically looking for information on time, Exhaust Gas Temperature (EGT), and N2 (which presumably stands for engine spool speed or rotational speed of the high-pressure compressor in a jet engine).
While the provided reference information mentions temperatures of 244°C and 477°C, and a general statement about the efficiency of automobile engines being limited due to overheating, it doesn't give a direct answer to the limitations on restarting an engine.
Typically, in aviation engines, one must consider the EGT and N2 disappearing margin to avoid engine wear or damage during restarts. An EGT that is too high could indicate that the engine is too hot, potentially leading to damage. Manufacturers provide specific guidelines that protect the engine during starting procedures, which include maximum EGT limits and waiting period, to ensure the components have sufficiently cooled down.