We met Marco Massola, Suzuki Marine Italia Technical Staff Coordinator, at Nauticstore in Gianola, Italy.
Among the subjects we dealt with and which we’re developing in the next few weeks, we talked about an essential component for outboards: propellers. In particular, we talked about how we must choose the right propeller for our boat.
In other words, which are the factors we have to take into account when purchasing a new propeller?
According to the Suzuki Technical Staff Coordinator, the propeller has, first of all, be able to reach the top of the rev range and express (in that range which goes from 5,800 to 6,200 revolutions) the maximum power, that is that one declared and labelled on the engine.
Of course, only a sea trial can help us to check whether these conditions are respected. However, before getting to sea, we have to consider some other factors.
First of all, the end use of our boat. Do I have (or am I going to buy) a fishing boat or a sportive rib? A small open cruiser or a tender?
Once this point has been established, other questions inevitably raise. For example: what’s better? A three-blade or a four-blade propeller? It’s not a matter of personal tastes.
“The more blades a propeller has – Marco Massola explains – the harder it will be to reach the maximum speed. On the other hand, the more blades there are, the more exuberant the couple is. As a result, planing will be easier and faster”.
So, if we prefer sailing faster, we’ll choose a three-blade propeller. On the contrary, a four-blade propeller will ensure better performances but lower maximum speed.
As regards materials, Suzuki offers two alternatives: aluminium and steel.
An aluminium propeller offers two advantages: greater lightness and lower cost. However, this material is not suitable for heavy powerful boats. When, in fact, power exceeds 100-140 Hp, aluminium blades might deform. This is why, steel propellers are recommended for outboards outputting more than 140 HP. They will certainly be heavier and more expensive but they won’t deform.