Prop selection....Previous Prop Unknown!

[nextboat1]

A good friend of mine came to me with this question, but I am unsure how to answer. Any help will be greatly appreciated!

He purchased a 1989 Sea Ray 220DA Cabin Cruiser. Overall length is 23.8'. It has a rebuilt 5.7 that has right around 300hp. The boat has Gen II transom assembly installed. The boat was purchased without the outdrive (due to theft) and thus no prop. He found a replacement drive and is now in need of a prop. He asked me what a good prop choice might be. The boat will spend most of its time at cruising speed or below and might see top end occasionally. I know that without the specifics it will be hard to determine, but what would be a good starting point as far as pitch and dia. for a boat this size? Sorry that I don't currently have any further info on the boat, and I thank you in advance for you advice.

 

[Bondo]

Re: Prop selection....Previous Prop Unknown!

A good friend of mine came to me with this question, but I am unsure how to answer. Any help will be greatly appreciated!

He purchased a 1989 Sea Ray 220DA Cabin Cruiser. Overall length is 23.8'. It has a rebuilt 5.7 that has right around 300hp. The boat has Gen II transom assembly installed. The boat was purchased without the outdrive (due to theft) and thus no prop. He found a replacement drive and is now in need of a prop. He asked me what a good prop choice might be. The boat will spend most of its time at cruising speed or below and might see top end occasionally. I know that without the specifics it will be hard to determine, but what would be a good starting point as far as pitch and dia. for a boat this size? Sorry that I don't currently have any further info on the boat, and I thank you in advance for you advice.

Ayuh,.... What gear ratio is the drive he found,..??

If it's a 1.50:1, I'd guess an aluminum 17" pitch prop might be a good startin' point,...

If it's a 1.65:1, I'd think a 19" pitch prop,..

With either, even if wrong, they'd still make good back up spare props to get home on,...

 

[steelespike]

Re: Prop selection....Previous Prop Unknown!

A reasonable starting point. If you report back with your results we should be able to tell if your setup is working.

 

[Starcraft5834]

Re: Prop selection....Previous Prop Unknown!

These boys will point you in the right direction with pitch and dia.....almost a 24 boot boat? I would strongly recommend a 4 blade prop in recommended dia and pitch....

 

[nextboat1]

Re: Prop selection....Previous Prop Unknown!

He just got back to me. The drive ratio is 1.47. He is guessing wot will be around 5500-6000 est.

 

[Slip Away]

Re: Prop selection....Previous Prop Unknown!

Estimate for WOT with 260HP 5.7L is way too high. 5,000 would be max. More like 4600-4800. Prop on my buddies 220DA is a 141/2" x 19p 3 blade aluminum.

 

[MikDee]

Re: Prop selection....Previous Prop Unknown!

IMO, a 14 1/2" x 19" sounds about right. I had that prop on my old 24' SeaRay cuddy, with a 260 Mercruiser.

 

[jestor68]

Re: Prop selection....Previous Prop Unknown!

Visit the Mercury(web site) prop selector and start with a dry weight of about 3700 lbs. Put in your estimate for people/gear and gallons of fuel to get the operating weight

Point and click to see a list of different Mercury props they recommend.

The list will include 17, 18,19, and even a 20 pitch, depending on what type of prop is selected(based on the end operating weight).