How does supercharging affect engine longevity?
That depends on the design of the supercharger system, as well as the manner in which a boat is operated. In general, the two biggest threats to engine longevity are detonation and excessive engine rpm. Detonation may be caused by several factors, but the primary factor is usually excessive heat. Cool intake air (also referred to as charge air) temperatures are the single greatest protection against detonation and engine damage. In fact, every 1° reduction in charge air temperatures typically produces a 1° reduction in exhaust gas temperatures. Cool charge air also produces more power per pound of boost, which means that an engine will make more power with less rpm. This in turn allows the use of a larger prop, which will decrease not only the typical cruising rpm of the motor, but also the average lifetime engine rpm. Decreasing rpm obviously increases engine longevity. Some other supercharger systems, on the other hand, actually raise the factory rev limiter as a standard part of the
