What is the minimum allowable lube oil temperature prior to jacking the main engine over?

The correct minimum allowable lube oil temperature prior to jacking the main engine over is 90 degrees Fahrenheit. This temperature is critical because proper lubrication of the engine's components is dependent on the lube oil being warm enough to reduce its viscosity, allowing it to flow properly. If the oil is too cold, it may not adequately lubricate the engine parts, which could increase wear or even lead to engine damage when jacking over the engine.

Maintaining the lube oil within recommended temperature ranges ensures that the oil can effectively perform its function, minimizing friction and enhancing the protection of engine components during operation. Hence, a lube oil temperature of 90 degrees Fahrenheit is established as a minimum to ensure the safety and efficiency of the mechanical processes involved.