prop size question

[jbauman102]

I have a Volvo Penta 5.7 gxi-e 275HP with dps f2 props on a 26.8 monterey now rider about 5500lbs. It does about 40mph at WOT. I was told I should have f4 props any I would like some advice or opinions please.

 

[steelespike]

Re: prop size question

Not a Volvo expert ,wouldn't know a F2 prop if I fell over it but::
We will need you wot rpm and gps speed to get an accurate indication of your setup.

 

[jbauman102]

Re: prop size question

The RPM is at 5000 wot and the speed is between 38-39 mph

 

[jestor68]

Re: prop size question

You can look up your engine in the Volvo data base; but it appears that the max rpm is 4600 rpm.

It that's the case, it appears that you could step up to the next higher pitch set to reduce your WOT rpm to within recommended limits and gain some speed.

 

[emilsr]

Re: prop size question

Changing from an F2 to an F3 prop set will lower your rpm at WOT by about 200. Changing to an F4 prop set will lower your rpm by about 400.

Bear in mind that in the heat of the summer you'll lose a couple hundred rpm, so see where the revs need to be and prop accordingly. Check the plate on the engine as the rev range (and power output) changed over the years on that particular engine. You'll want to be right at the top of the recommended rev range in cool weather.

 

[jbauman102]

Re: prop size question

What and where is the "plate on the engine"