What pitch SS prop for a 3.0 Volvo

[ss9940]

Hi everyone!<br /><br />I'we got a 17' Caravelle with a 3.0 Volvo. I currently have a 15 X 17 alu prop, but i would like to change it to a SS prop to increase performance. According to IBOATS internet site, the following props can be used:<br /><br />14 3/4 X 17<br />14 7/8 X 15<br />14 1/2 X 19<br />14 1/4 X 21<br />14 1/4 X 23<br /><br />I would like to know if someone has experienced a combination of the above props with a 3.0 and with what results. I know that pitch decreases WOT RPM, but i think those props can be used (as i said, according to IBOATS prop selector). SHARE YOUR EXPERIENCE WITH ME! <br /><br />Thanx,<br /><br />Alex

 

[tommays]

Re: What pitch SS prop for a 3.0 Volvo

if your getting the correct WOT now with the now with the 15 x 17 then your going to have to stick with that size<br /><br />the props may fit but the motor does not make enough HP to turn the bigger ones at the correct RPM<br /><br />i would thing you could use a bigger prop BUT every boat is different and props are very trial and error<br /><br /> and SS props are very costly to pick the worng one <br /><br />in the states we try to borrow one from are nice friend or prop man before we buy it <br /><br />tommays

 

[Swishguy]

Re: What pitch SS prop for a 3.0 Volvo

For running a stainless drop down 2 degrees. Get a 15 X 15 stainless. I have been running different boats for over 20 years & on every boat I have owned dropping 2 degrees on a stainless gets you bang on rpm,s.

 

[ss9940]

Re: What pitch SS prop for a 3.0 Volvo

I agree, but the props suggested on iboats decrease in size and increase in pitch, so that should about cover the RPM (just a thought) - or am i wrong?

 

[tommays]

Re: What pitch SS prop for a 3.0 Volvo

you have to no your current RPM or you cant change props unless you want to throw money away <br /><br />it would also help to no the boat brand and size as a member may have the same boat and already tryed different props and no the results<br /><br />tommays

 

[ss9940]

Re: What pitch SS prop for a 3.0 Volvo

As i said in the 1st post, it's a 17' CARAVELLE bow rider - as a reference

 

[tommays]

Re: What pitch SS prop for a 3.0 Volvo

and your current RPM and speed is ?<br /><br />tommays

 

[ss9940]

Re: What pitch SS prop for a 3.0 Volvo

Hmmm... that one i don't know, cause i installed a brand new 3.0 GM engine and didn't want to max it out yet... I got over 4000 though - i would estimate the max at around 4500 RPM (the recommended RPM are 4200-4600 if i'm not mistaken) and a little over 35 MPH.<br /><br />How much does size affect the max RPM? If i, for instance increase pitch by 2, how much must the size be decreased to achieve the same WOT RPM?

 

[tommays]

Re: What pitch SS prop for a 3.0 Volvo

<br /><br />alex<br /><br />this is my boat its 19 ft with a 3.0 GM motor with a merc outdrive with a 1.98 to 1 final drive ratio <br /><br />the merc verison is rated a 4800 RPM <br /><br />i have tryed a lot of props over the years and i use a 15 x 17 if i am going to pull a tube or have a lot of people on the boat<br /><br />for normal use with 3 people and a full tank of fuel (136 liters)i use a 14 x 19 prop this gives me 42 mph by GPS at about 4800 RPM<br /><br /><br />the bigger prop makes it much harder to get the boat going so i use a homemade PVS (Performance Vent System)this allows the prop to slip at lower speed makeing it easery to get the boat on plane at does not affect the top speed<br /><br />

<br /><br />in my case the next size prop is a 14 x 21 i have tryed it and it results in slower speed and to much load on the motor <br /><br /><br />until your motor is fully broken in and you no the final RPM you cant chose the correct prop<br /><br /> http://www.mercurymarine.com/everything_you_need_to_know_about_propellers5 <br /><br />props are very complex you should enjoy reading this<br /><br />tommays

 

[ss9940]

Re: What pitch SS prop for a 3.0 Volvo

Thanx, tommays! Do u use aluminium or SS props?

 

[tommays]

Re: What pitch SS prop for a 3.0 Volvo

i run in a lot of shallow water so i stick with aluminium props its much easyer on my wallet <br /><br />i dont feel there is a lot to gain in speed in my boat at this point unless i put a V-8 motor in which is not going to happen<br /><br />tommays