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Old 01-05-2014, 11:19 AM   #26
Al
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City: ketchikan, Alaska
Vessel Name: 'SLO'~BELLE
Vessel Model: 1978 Marben-27' Flybridge Trawler(extended to 30 feet) Pilothouse Pocket Cruiser[
Join Date: Apr 2012
Posts: 2,206
Have we come full circle with the information provided by Reiziger,FF,and Rick? The question revolved around a proper "cruising" propeller. The conclusion drawn is to overload the propeller to achieve hull speed or there about, at a 'working' RPM. In other words, free from the dock in a pleasure boat one would not achieve WOT yet at a lower RPM achieve hull speed or there about. The gain is a working engine, higher engine temperature (Not excessive just a tad higher) quieter engine sound (deeper not screaming).
Those factors are involved with a decision to increase the size of our current wheel. The current wheel matches what the conversion formula suggested in the first post to IwillIT. We do achieve WOT running free, (3000 RPM) Hull speed is achieved at 2400 RPM. Engine temp running about 175 degrees. By either increasing diameter or pitch we will lower the RPM, maintain hull speed, and increase operating temperature.
With the knowledge of what increasing diameter and increasing/decreasing pitch can provide the chore of finding a matching wheel begins with confidence.
Been a great thread, thanks to IwillIT and participators.
Al Johnson-Ketchikan (Bridge to Nowhere) Alaska
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