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Old 01-28-2015, 09:42 AM   #17
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Join Date: Oct 2007
Posts: 18,390
OF course if you are content with just cruising as economically as possible , a single engine with deep tranny reduction run at the MFG rated sweet spot (as chosen from his fuel map) will require nothing , but a fairly expensive prop.

As diameter gets bigger the price goes way up. Price a 24 inch and 36 inch to see.

Those seeking the ultimate might work in a 2 blade prop too.

OF course a boat set up this way will never pull max rated RPM on the pin.

Want cheapest ? Do that the big boys do almost full power ( 96 to 105RPM) and accept a slow down in over 30K of breeze.

OF course these boats are so optomized for one speed the engine required modification , and different operating techniques to slow cruise at 85 RPM.

Even the bulbous bow needs modification, but when the fuel burn is in TONS PER HOUR,,,,,

Most boats are fitted with ove rsized engines as they are cheaper to purchase for the stock boat builder.
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