Propeller diameter?

[WTR4FUN]

I have been browsing the search funtion trying to get some usefull information in regards to what the benefit's or disadvantge's would be to replacing a prop that has a larger or smaller diameter but the same pitch. Can anyone provide some usefull info on this please?


Thanks

 

[junior1113]

Re: Propeller diameter?

not very noticable, if its 1/4 or 1/2 inch all prop manufactures make different diameter. larger diameter harder to turn less wot rpms. hope this helps

 

[hwsiii]

Re: Propeller diameter?

Fun in most cases you would use a larger diameter prop for heavier boats and a smaller diameter for lighter boats. Prop Slip will tell you which one you normally need, a high percentage of prop slip means you would normally want to have a larger diameter for more surface area on the prop so prop slip percentage will go down and speed will go up.

H

 

[Dhadley]

Re: Propeller diameter?

A lot depends on what style prop we're talking about. If we're talking about a prop for a barge or pontoon it means one thing. Generally that it'll hold better in turbulant water due to different cup angle and position. 4 stroke specific props generally have a larger diameter with less rake. "Offshore" type props usea larger diameter to help hold water in rough / following seas. If we're talking about a performance type prop, diameter means something else. Generally that you can run a higher X dimension.

It has a lot to do with blade design & intended use rather than a simple matter of diameter only.

 

[WTR4FUN]

Re: Propeller diameter?

thanks for the feed back,it sounds like there is not much to be gained for my type of application, and I should focus more on pitch and number of blades.

thanks

 

[Dhadley]

Re: Propeller diameter?

Could be but without knowing what boat / motor you have it's hard to say. Or even guess.

 

[Silvertip]

Re: Propeller diameter?

Look at it this way -- if you look at inexpensive aluminum props for example, you will see that a 17P prop of the same design from the same manufacturer as a 15P, the diameter would be about 1/4 inch less. Same going from a 17 to a 19. Conversely going from a 15 to a 13 would result in 1/4 inch more diameter. So depending on what you are comparing, diameter is not anything you can select -- it is a function of prop design.