Help me pick a prop for my Sea Ray (results)

[109jb]

I have a 1988 Sea Ray Seville 16 foot. It is powered by a 1997 115 hp Mariner inline 4-cylinder. Right now I have an aluminum Black Max 12.75" x 21" pitch prop. With the current prop, I see 5,000 rpm WOT and right at 50 mph on the boat speedo. The boat is used for tubing, skiing and fishing. I am looking to upgrade to a stainless prop. I've never had a stainless prop before but have heard that i can improve my holeshot while keeping the top end where its at. Is this true?? Is 5,000 rpm about right for this motor or can it take a little more??? What prop would you prop experts recommend for this boat/motor/use combination?? 3-blade or 4-blade?? I'd rather buy right the first time.

Thanks

 

[109jb]

Re: Help me pick a prop for my Sea Ray

Re: Help me pick a prop for my Sea Ray

Anyone??

I did find out that the 5,000 rpm I'm getting is right where the book says it should be, so the aluminum prop is sized right.

 

[rndn]

Re: Help me pick a prop for my Sea Ray

Re: Help me pick a prop for my Sea Ray

One of the sources I looked at stated your rpm's should be 4750-5250, which means you really could stand to lose 1 inch of pitch. The SS will also bring down the rpm's a little so you may want to try a 20 or a 19 inch SS prop.
As far as a 3 or 4 blade prop it depends on your boat. A 4 blade will provide quite a bit of stern lift and really assist you in pulling the tube or skiers out of the water.

 

[109jb]

Re: Help me pick a prop for my Sea Ray

Re: Help me pick a prop for my Sea Ray

Thanks for the reply. I've also been searching around and it sounds like you gain about 200 rpm for each inch of pitch decrease. Is there a similar rule of thumb for Al vs. SS? Also, does 3 vs. 4 blade affect rpm? I'm thinking about the 4 blade, but can't seem to find an online vendor that has SS 19P 4- blade props.

 

[109jb]

Re: Help me pick a prop for my Sea Ray

Re: Help me pick a prop for my Sea Ray

Well, I ultimately decided to go with a Solas 13 x 19 4 blade prop. Wouldn't you know it would be delivered on a day when it is raining!!!

 

[109jb]

Re: Help me pick a prop for my Sea Ray

Re: Help me pick a prop for my Sea Ray

Well, I was able to get the new prop wet today and all I can say is WOW. The change in the holeshot is incredible. I guess it is in part because of the lower pitch, and also the switch to 4 blade SS from 3 blade AL. I am much closer to my desired rpm of 5250 with the tach showing about 5100 WOT. I actually gained about 2 mph top end too, but can't really use it because I also experienced chinewalk for my first time ever. Trimming it in just a touch solved the chinewalk, and put me at the same top speed I had with my aluminum prop. As a reminder I went from a Mercury Black Max 12.75 x 21P, 3 blade AL to a Solas HR Titan 13 x 19P, 4 blade SS. I am very pleased with the results.

 

[Scorpion 210 LTD]

Re: Help me pick a prop for my Sea Ray (results)

Thanks for the update, it is always nice to hear real world results!!