Posted by JimM on September 20, 2002 at 05:32:03:
In Reply to: Gear Ratio posted by Haji on September 20, 2002 at 05:05:09:
I don't have the background or magic formulas, but it does seem to me that prop pitch, boat length (LWL), displacement, and hull speed ought to be part of the consideration. I do know that every displacement hull (which this likely is, with that huge prop) has a maximum speed beyond which no engine on earth can drive it. Perhaps you need to turn the prop at the rpm which could theoretically give you that speed, with an adjustment for slippage.
Boatbuilder magazine did an article on props a couple of years ago. Otherwise, consult a naval architect.