Originally Posted by manyboats
You say ... "diamater should be 32" and 28" pitch".
That would be like your boat w a 500hp engine and a 60" prop.
You can't prop Breadbasket for the engine because she can only use a small fraction of her power. Breadbasket needs to be propped to her hull. No need for more than 20" in diameter as long as enough pitch can be had to propel the boat easily at hull speed and a bit more (7 knots max). Probably will need over 20" dia to have a prop that will advance through the water at about 8 or 9 knots ... with the proper amount of slip and enough thrust to push the boat (15 to 20hp).
Agree... If 40 or 50 hp were used, there would be no need of that diameter to absorb the power and 20 or 22" would be enough. So if the engine were derated to the necessary power + reserve he could run the numbers and get the proper wheel assuming
he is willing to change transmissions. As it stands now, if that smaller wheel were adopted, the engine could
overspeed so needs an unnessarily large and iinefficient (friction) prop. That 50 hp will be developed at less than 1/2 current rpm so pehaps 1.5 or 2:1 transmission would be required.