An increase in manifold pressure with a constant RPM will cause the bearing load in an engine to...

An increase in manifold pressure while maintaining a constant RPM is indicative of an increase in the amount of air-fuel mixture entering the engine cylinders. This enhances the engine's power output because it allows for more effective combustion and can lead to an increase in the thrust produced by the engine.

As the combustion process becomes more vigorous with the higher manifold pressure, there is more force exerted on the engine's components—specifically the bearings that support the moving parts such as the crankshaft. This results in an increase in the bearing load, which is the force transmitted through the bearings as they support the engine's rotating assembly.

Therefore, the increased manifold pressure directly correlates with the increased combustion force, leading to a subsequent rise in bearings' load, thereby justifying the conclusion that bearing load will increase. Understanding this relationship helps in anticipating the mechanical stress and ensuring that all components are capable of handling the increased loads during operation.