Volvo Stainless Duo Prop

mentooriento

Recruit
Joined
Oct 2, 2012
Messages
3
I have a 23' Seacraft Custom Flybridge with a Volvo 200HP and 290 Duo prop. I currently run a A4 duo prop and get 3900 RPMs at wide open throttle. I tried the C3 Stainless and was only able to get about 3200RPMs. Normal trolling speed with the A4's at 2100-2200 RPMs typically average 7.5-8.5 knots. With the C3, I have to push it up to 2500-2600 RPMs to get the same speed. Anyone have any idea what size stainless props should I be using to get the same performance of the A4's?
Thanks in advance,
Darren
 

Maclin

Admiral
Joined
May 27, 2007
Messages
6,761
Re: Volvo Stainless Duo Prop

The charts in here may help show the "overlap" between the A series and the C series.

What engine do you have? 200hp sounds low for a 23 footer unless it is a diesel :)
 

Attachments

  • Volvo_Prop_guide_2005_2006.pdf
    405.4 KB · Views: 0

mentooriento

Recruit
Joined
Oct 2, 2012
Messages
3
Re: Volvo Stainless Duo Prop

The charts in here may help show the "overlap" between the A series and the C series.

What engine do you have? 200hp sounds low for a 23 footer unless it is a diesel :)

Thanks Maclin. It is a diesel and I could definitely use more power especially since the boat is on the heavy side. Wide open with the A4 aluminum props (which I get the recommended max RPMs of 3900) is about 24 knots.
In the link you provided, they don't even show a C3 for the AD41P with 1.95 ratio.
Question, would the max RPMs increase the higher the prop number I choose? If I only get 3400 RPMs @ WOT with the C3 props, should I get more (like 3800 RPMs) with C4s? Sorry for so many questions, just not familiar with how the prop numbers work.
Thanks
 

Maclin

Admiral
Joined
May 27, 2007
Messages
6,761
Re: Volvo Stainless Duo Prop

The lower the number the higher the RPM and the lower the top speed. An A3 set would let your engine rev higher if it can, and if it does then the top speed would be about the same. You mention you can hit the recommended top rpm now, so that is about where you need to be.

If you are getting lower top speed at the same RPM's with the C3 set AND cannot get to top RPM's then I am not sure what to recommend.

I will mention that I have only seen the A series aluminum recommended for diesels. They have thicker construction and that one extra blade on the rear prop to hold up under the diesel's torque.

As you can read in the pre-amble in each prop section for the A and B and C series duoprops in that prop guide, stainless duoprops are recommended for speeds above 35 knots. After reading that in the B series section then reading the A series preamble I'm thinkin' that Volvo is intending the diesels to stay with the A series props to keep from blowing the props out of the water with all that low speed torque.
 

mentooriento

Recruit
Joined
Oct 2, 2012
Messages
3
Re: Volvo Stainless Duo Prop

Thanks Maclin,
Appreciate the feedback. Not sure what to do. I would like to run the stainless props but the A4 pushes the boat with the right max RPMs. Would be ideal to find similar or better performance in the C series.
Thanks for your input.
Mahalo!
 
Top