Volvo Penta 280 Prop selection

[cheechako]

My boat has a 15 x 19 prop on it. It doesnt get to max rpm... far from it. The Previous Owner said it should have the other prop on it. That prop is 16 x 17. (The prop selector for this AQ200 (200 hp) is more in the 15 x 15 range.) here's the question: is the 16 x 17 a prop that will give me more RPM? It's less pitch by 2", but it is an inch bigger diameter...? is there a rule of thumb for dia vs pitch comparison (ie: if i have a 15 x 15 prop and want to use a 16 x ? prop, would a 16 x 14 be equal performance to the 15 x 15? or something like that?)

 

[jestor68]

Re: Volvo Penta 280 Prop selection

The recommended rpm range for your motor is 3800-4200 rpm, with the max being 4400 rpm. You want to prop it to run at or near the top limit with a light load; just one or two people in the boat.

Depending upon how much rpm change you are looking for, it might be best to stick with the same diameter(15) when switching props if you expect the normal 300-400 rpm change.

You can change diameter if you desire to lessen the rpm change between pitch changes. For example, an inch increase in diameter will negate some of the effect of a 2 inch pitch change by roughly half.

Based upon what WOT rpm it's turning now, I'd advise staying with the same diameter(15) unless you have a large, heavy boat. In that case more diameter/less pitch would probably work better.

 

[cheechako]

Re: Volvo Penta 280 Prop selection

OK, thanks for that. I have the 16 x17... so I might just give it a shot, not too hard to change it again. Or maybe I'll find someone to swap a 15 x 17 or so for the 16.