290 Sundancer Prop Selection advice

Hello. I'm a long time lurker, first time poster, and looking for some prop advice.

I have a 99 290 Sundancer, twin 4.3, 190HP, Alpha drives, and she's been mine since new. The boat came with stainless props, 48-825900-19 (14X19), and she has always accelerated about like a pig. Even when new and with a fresh tune and bottom job, WOT produced only 31MPH (GPS) and indicated 4000-4200 RPM. A recent encounter with a rock resulted in undesired changes to one prop's geometry and has given rise to the opportunity to prop shop.

The boat weighs 10500, add 600 lbs for captain and crew, and another 800 lbs for fuel, water, and gear. My objective is a bit better hole shot to get to plane more easily, cruise at 25-30, and an occasional run at 30+ without WOT.

I'm considering moving to aluminum Solas Amita-4, and based on what I've been reading on this forum and elsewhere, I'm considering 14.5X17 to improve the hole shot and hopefully get me up into the middle of the spec 4400-4800 RPM range at WOT without sacrificing too much top end.

Am I going the right direction? Anyone else with similar experience and/or a few words of advice?

Thanks in advance

Forgetta 'bout it
Canyon Lake, Texas

Re: 290 Sundancer Prop Selection advice

Am I going the right direction?

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Ayuh,... Definitely the Right way... I donno about that particular prop though...

Re: 290 Sundancer Prop Selection advice

forgettaboutit, since you already have 4 blade stainless props on your boat we need to know the blade geometry of these props so we can compare the two sets and see if the Amitas are better for your particular application.

My information shows that you should have a gear ratio of 1.8:1 and your RPM should be between 4,400 and 4,800 RPM at WOT, please Verify this for me.With these numbers I am showing you have a prop slip of right at 25% which is a little bit under normal for a heavy cruiser, which is good.

The blade geometry difference is going to mean more than the difference in pitch, because you could just drop the pitch to 17" and buy new props like the ones you have now and increase your hole shot, lower your prop slip and probably not lose any top speed. And as these are stainless props you have already they theoretically have thinner blade sections and better design elements than most aluminum props.

In my opinion, you need to bring the good prop that you still have to a prop shop and have him tell us what the design elements in these props are. He may do it for free or charge you a small fee, but it is definitely worth it to find the right props in the long run.

The props you have now are not familiar to me and are not in my database, so we need to know whether your current props are fixed pitch, regressive pitch or progressive pitch and if so how much, we also need to know if they are 0 rake, flat rake or progressive rake and how many degrees of rake, as well as whether they have cup on the trailing edge or the blade tips or cup in both areas. THIS IS IMPORTANT.

With this information we can then make a more informed decision about which set of props are better for you.

The boat weighs 10500, add 600 lbs for captain and crew, and another 800 lbs for fuel, water, and gear. My objective is a bit better hole shot to get to plane more easily, cruise at 25-30, and an occasional run at 30+ without WOT.

I'm considering moving to aluminum Solas Amita-4, and based on what I've been reading on this forum and elsewhere, I'm considering 14.5X17 to improve the hole shot and hopefully get me up into the middle of the spec 4400-4800 RPM range at WOT without sacrificing too much top end.

Click to expand...

You are wanting to have a better hole shot AND more top speed, which are usually mutually exclusive of each other, but NOT always. If we are able to raise the stern of your boat higher in the water column and reduce wetted surface area it is a possibility. Also with stern lifting props normally you can plane and hold plane at lower speeds.

Getting your RPM up to manufacturers recommended specs is Definitely a good thing to do.

We definitely can stop you from losing much top end.

I would also appreciate it if you could send me 3 different views of the prop you have now.

I ask for a LOT of information, as always, BUT it is because I want to find a better prop for your boat, and I have found in the past that if I do it systematically I always end up with good results.



H

Re: 290 Sundancer Prop Selection advice

Thanks for the detailed response, hwsiii.

Here's a link to a set of props that match what I currently have (Mercury/Mariner Offshore 4 Blade 19P S.S. Prop):

http://www.sportfishermen.com/board...ner-offshore-4-blade-19p-s-s-prop-484092.html

You're spot on with the gear ratio and recommended WOT RPM.

The reviews I've read indicate the Amita is a decent stern lifting prop, but I don't know how it compares to what I already have. I usually fiddle with the tabs to get on plane as it is, so I'm hoping with a little more lift and a slightly larger diameter wheel I'll be better off all the way around.

Cheers.

Re: 290 Sundancer Prop Selection advice

forgettaboutit, the pictures were very good, if you will just take the prop to a prop shop now, we will know the design elements and can do a good comparison between them, so I will be waiting for that information and we ought to be able to make an informed decision at that time.
I believe the Amitas will be a very good choice, but when we have the elements to analyze we will know much better.



H