What is likely to occur if a reciprocating engine is operated at high power settings before it is properly warmed up?

Operating a reciprocating engine at high power settings before it is properly warmed up can lead to oil starvation of bearings and other critical components. When the engine is cold, the oil is thicker and does not flow as freely as it does when the engine reaches its optimal operating temperature. At high power settings, the engine requires an adequate supply of oil to ensure proper lubrication to prevent metal-to-metal contact. If the oil does not circulate sufficiently due to increased viscosity at low temperatures, it may not reach the bearings and other parts effectively, potentially leading to increased wear and even engine damage.

The other options represent potential outcomes of improper engine use during warm-up but do not directly address the critical issue of lubrication that arises specifically when high power settings are applied too early. For instance, while excessive thinning of engine oil can occur under various conditions, it is not the primary concern during the initial warm-up phase. Similarly, accelerated oil breakdown and oxidation typically result from prolonged high temperatures and can occur later in the engine's operation, but are not immediate risks associated with cold operation. Increased cylinder wear is a consequence of poor lubrication but is a more gradual process and relates less directly to the immediate circumstances of operating at high power without proper warm-up.