14 3/8 x 15 vs 15x15 on volvo penta 3.0 sx drive

[aerobat]

hello !

i currently have a stainless turning point 14 1/2 x 17 on my volvo penta 3.0 GS with sx drive but that prop is a little bit to big on my 21ft cabin boat. it tops out at about 28 mph but revs only to about 3900rpm so i think a 15pitch is the way for me.

i looked at the offers at iboats and would like to purchase - i see a apollo xhs in 14 3/8 x 15 or a express ( turning point)
in 15 x15 . both are stainless

am i right that a bigger diameter at a given pitch will tend to give a better hole shot but reduced top speed?

does the stainless props have generally cavitation holes ? ( my current TP has )

any input and hints are very appreciated !

thanks in advance

 

[steelespike]

Re: 14 3/8 x 15 vs 15x15 on volvo penta 3.0 sx drive

Usually larger diameter will help grip but could restrict rpm
But generally diameter is a secondary consideration,unless there is a specific problem
that an increase or decrease may help.
For more predictable results
usually it is suggested to stick with a brand and model of prop if it works for you
Also same material.If your satisfied with the present
prop but for the rpm It would seem the same model in a15" would do well.
Vented props introduce a little exhaust into the the blades allowing the motor to rev easier.
As I understand it They aren't as effective on 4 strokes. No, stainless props aren't all vented.