Ventilation and Cavitation are two completely different phenomena that are observed, under specific conditions, during the rotation of the propeller and their understanding is often confused. Both the cavitation and ventilation of the propeller (except in certain special cases) have a negative impact on the performance of our boat.
With the memories of the unforgettable moments Corsair 31 gave us against the huge waves of the Atlantic Ocean being fresh, I took my position behind its cockpit. However, this time, the aim was not to travel, but to test the performance of Bravo I FS propellers fitted to the new twin 250hp Optimax which were mounted on its transom.
Revolution is a 4-blade propeller, designed to run close to the sea surface and operate very well even with small amount of water, a fact that makes it perform very well in high engine’s mounting heights as well as in excessively elevated trim settings of the engine.
Sea Quest is one of the best built and seaworthy ribs of the Greek market and is characterized by its particularly comfortable facilities and the impressive soft ride.
Being aware of the performance of the Sea Quest with the propeller of Suzuki, we wanted to see whether the Bravo I FS fits both the hull and the large (numerically) gear ratio of the Suzuki DF 225hp.
The Trophy Plus is one of the most popular propellers of Mercury Marine, due to the very good features of its design.We tested the 23΄΄ pitch Trophy Plus propeller on a Suzuki DF 140hp which was mounted on the transom of the Larsen 4.95m.
The Trophy Plus is a 4-blade stainless steel propeller by Mercury Marine which is available in a diameter of 13 ¾΄΄ and in pitch sizes: 17", 19", 21", 23", 24", 25", 26", 27" and 28 inches.
Shorter pitches (17΄΄ and 19΄΄) are recommended for 75-115 hp outboards while longer pitches (21΄΄- 28΄΄) are recommended for 135-225 hp outboards.
It is a fact that the choice of the right propeller is often quite complicated since it depends on many factors, the understanding of which is often quite difficult.
Usually we have to use a number of rules and theories so as to be able finally to choose the proper propeller.
It is known that the choice of the propeller directly affects the engine’s performance. But how many of us know that the propeller affects the outboard’s longevity apart from the preformance?
It is very well known that every change in propeller’s pitch has a direct effect on the performance of our boat. It is also known that each inch of the pitch «costs» 150-200 rpm for our engine at WOT, a relationship inversely proportional.