difference between 14' and 15" prop

[diezelducker]

I am wondering what the diameter of a prop does to the ratio? If you have a 15X15 and then go to a 14X17 what happens? More power, less power, better holeshot, or better topend? No matter what drive it goes on it must have the same effect, right? I am only snooping around a bit and am just wondering.

 

[Bondo]

Re: difference between 14' and 15" prop

Ayuh,... Shop for Pitch,...
Diameter is just a function of Blade Design...

 

[hwsiii]

Re: difference between 14' and 15" prop

Diezel, theoretically speaking in the same make and model of prop the 15" produces more low end performance, for pulling skiers for instance, and acceleration with less prop slip. It will carry a heavier load than the 17" and produce more RPM in most cases. The 17" will produce higher speeds if the boat is light enough to not increase the prop slip too much, but if the weight or deep vee design is too high it will lower the RPM a lot and create a lugging condition in the motor thus loading the motor and causing more fuel consumption at almost all speeds. Theoretically it can actually lose speed from the RPM dropping and slip increasing. But if the hull is light enough you can gain good speed. You have to match the prop to the circumstances.

After saying all of that let me tell you that with all of the different blade geometry configurations available today it is not always easy to tell what it will do. You always want to try and match the prop geometry to what type of hull you have and what your particular uses and needs are for that vessel.


H

 

[diezelducker]

Re: difference between 14' and 15" prop

Thanks for the info. I have 3 different props any way. I do have a s.s. 14x19 and it's my favorite. the others are aluminum. Maybe the s.s. is just the right pitch or something, but it saves me alot on fuel. Basicly biggest bang for the buck. The others perform just a tiny bit better but this one performs really good and saves fuel. So I run the s.s. as my main. The other 2 are just for skiing,tubing and the like. Anyhow thanks for the info.

 

[steelespike]

Re: difference between 14' and 15" prop

Be sure your motor is able to operate within its rpm range at wot.
If your picking a prop without a tach a worse case rpm result could cause premature problems with your motor.