prop diameter. Need prop advise for a 24' boat

Cptkid570

Ensign
Joined
Oct 18, 2005
Messages
967
I can use a prop calculator to show the probable differences in performance between different pitched props. But what about diameter?

How much difference is there between a 14", 14 1/2" and 15" diameter prop?

My boat is 24' long and weighs about 4000 pounds unloaded (1996 Four Winns 240 Horizon - bowrider). Pushed by a 260hp Mercruiser (not the original engine).

The manufacturer tested the boat with a 14 1/2 x 19 prop and published their specs off of this prop. I've driven the boat with a 15 1/4 x 15 prop and a 14 x 17 prop. And I haven't come close to the manufacturers specs.

I know that the manufacturer probably tested the boat unloaded with 1 person or something..but, still, I'm not close. And, by the prop calculator, I'm getting more slippage with the 14 diameter prop. So, I like the thought of the 15" diameter.

I'm wondering what would be the best prop for me.... and am wondering what the difference would show between a 14", 14 1/2", and 15" diameter. I'm thinking that a 19 pitch may be over-propping the boat and am thinking of trying a 15x17.

Just want to see what everyone thinks.. if you have a similar size, weight and horsepower boat, I'd like to hear about your trials and errors were when finding your right prop.
 

Cptkid570

Ensign
Joined
Oct 18, 2005
Messages
967
Re: prop diameter. Need prop advise for a 24' boat

PS - before anyone asks about WOT, 1. I don't know the accurracy of my tach.. and 2. I'm more concerned about the best prop for cruising speed and getting on a plane...not top end.

But, that said, I believe i was reaching WOT with both props I tried.
 
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