Eliminating Cavitation
Boaters who know a great deal about propellers understand the importance of choosing one that will exhibit as little cavitation as possible. Nissan outboard propellers, like all marine propellers, are not completely immune to cavitation issues. However, when Nissan outboard props are correctly paired with an appropriate choice of motor, cavitation can certainly be minimized. But what exactly is cavitation?
Cavitation: The Basics
Cavitation is a natural consequence of the action of a propeller underwater; the phenomenon has long been understood in a physics context. Cavitation happens when small cavities in water are formed and then are instantly filled in with liquid. It results from rapid alterations to the pressure being exerted on a section of water. Cavities form because pressure is lower for a fraction of a second and they fill in as pressure increases.
Why Excessive Cavitation Should be Avoided
Too much cavitation can cause wear and tear on moving parts of an engine. One common kind of this wear and tear manifests itself as metal fatigue on the surface areas of a propeller. Just as a strong wire can be made to break by bending it back and forth too many times, so can surface areas become damaged as cavitation stresses them.
Marine propellers are tested in a wide variety of contexts during design in order to enhance characteristics that will help to reduce cavitation. Still, the best way to reduce it still further is to make sure that your aftermarket Nissan outboard propellers solution produces a good match with your motor.
Making Sense of Propeller Dimension Figures
When shopping for aftermarket Nissan Boat Propellers for the purpose of improving some aspect of watercraft performance, consumers will probably notice immediately that propellers are often described in terms of dimensions. At first glance, these dimension figures make little sense. For example, a certain class of Nissan props may be listed as having dimensions of 12″x 9″.
While these dimensions are those of a rectangle, they also apply to propellers, which are circular in nature. The educated boating enthusiast knows that the right way to make sense of the dimensions is to know that the two numbers describe two different things. The first number given refers to the diameter of the propeller and the second number refers to its pitch.
Diameter refers not to the size of the central hub, but instead to the size of the circle that the blades make as they rotate. Pitch, in contrast, describes the amount of linear distance that the watercraft will move forward as a result of the propeller blades making one complete rotation. Pitch, however, is an idealized number that treats the propeller as though it were moving through a solid, stable medium such as a soft wood. The actual distance a boat moves forward is less than the pitch stated because “slippage” occurs due to factors related to the nature of moving water.
Nissan propellers with dimensions of 12″x 9″ are therefore 12 inches across and have a maximum pitch of nine inches. The actual distance a boat moves forward with such a prop will depend on variables related to boating conditions.