Which type of flywheel is likely to accelerate an engine to top no-load speed more slowly?

A high-inertia flywheel is designed to have a greater mass or moment of inertia, which means that it stores more energy and takes longer to accelerate in response to changes in engine power. When a high-inertia flywheel is used, it resists rapid changes in rotational speed. This resistance means that when the engine is trying to accelerate to its top no-load speed, the flywheel’s added weight will absorb some of the energy, leading to a slower acceleration.

In contrast, low-inertia flywheels are built to be lighter and can respond more quickly to engine power changes, allowing for quicker acceleration. Medium-weight and variable inertia flywheels also have designs that can accommodate faster changes in rotational speed compared to high-inertia types.

Thus, the characteristics of a high-inertia flywheel lead to a situation where it accelerates the engine to top no-load speed more slowly due to its inherent design aimed at maximizing energy storage rather than responsiveness.