theoretical question.

[Wee Hooker]

Assuming the same motor, hull and prop design (basics) what is the expected difference in going to a :

1) Stainless prop of same pitch?
- Should RPM's stay teh same? Go up? down?
- Expected performance change in mid and/or top end?

2) 4 blade prop of same pitch?
-Should RPM's stay teh same? Go up? down?
- Expected performance change in mid and/or top end?


Thanks in advance.

 

[steelespike]

Re: theoretical question.

Assuming the same motor, hull and prop design (basics) what is the expected difference in going to a :

1) Stainless prop of same pitch?
- Should RPM's stay teh same? Go up? down?
- Expected performance change in mid and/or top end?

2) 4 blade prop of same pitch?
-Should RPM's stay teh same? Go up? down?
- Expected performance change in mid and/or top end?


Thanks in advance.

It is difficult to deal in absolutes on what a prop change will do;that said.
1,changing from al. to ss will generally improve overall performance.
The degree would depend on the design of each prop.
There will likely be an rpm change how much and up or down would vary.
depending on design.
2, Generally the 4 blade can improve low -mid range performance with a slight reduction of top end speed and rpm. How much again varies depending on design. If you go to the prop store here and read the prop helps at the top and bottom of the page you'll get the idea of the various designs and their affects.
The experts can explain the finer points of prop design.

 

[Dhadley]

Re: theoretical question.

With todays 4 blade designs it's not unusual to find that the right style 4 blade is faster than a good 3 blade prop.