Changing from Stainless to Aluminum propellor

[mupparpa]

I'm changing my 2005 JC Tritoon 266 with a 5.0 MPI 260hp I/O from a stainless prop to an aluminum because the slip I am in is surrounded by rocks. So I don't want to chance damaging my outdrive if I hit the rocks with the stainless. First is that a real concern with a stainless hitting rocks at an idle rpm that I would damage the outdrive? Second it currently has a Mercury Vengeance 48-16316 19P stainless prop on it. So it's 14 X 19. I'm looking for what might have equivalent performance characteristics in an aluminum prop. I've seen feedback where it says I should drop down 2 to a 17P going to an aluminum.

Also, the slip I am in requires a 90 turn that my Tritoon barge cannot make in on shot. So I have to back it up and finish the turn putting me within feet of the rocks (thus why I'm concerned about damage). Someone told me that if I went to a 4 blade prop it might give me a tighter turning radius. Is this just wishful thinking I'm trying to understand the logic of this as I would think throttle control would be more important than blade count. Thanks for your help.

 

[Texasmark]

Try the Turning Point (brand) Hustler (model) aluminum which iboats sells for a song....hundred bucks range You can pull up their www and see all the goodies it posesses....actually everything you get in a good SS except thin blades due to the material differences but they do use their own processed aluminum, said to be stronger and thinner than most alum in most propellers.

4 blade vs 3 for backing or going forward at the same pitch-RPM obviously more paddles in the water, more water being moved.

I think you are wise in making the change.

 

[mupparpa]

Thank you I will look into their propellers as well.

 

[jimmbo]

Examine the TP prop thoroughly before buying it. I have seen many with one blade of the 3 that 'Doesn't look like the others, one blade that doesn't belong', usually looking like a change in Rake on the rear half of the blade.
A TP blade is considerably thicker than a Merc/Quicksilver AL blade. The are a Price Point Prop.

 

[mupparpa]

Thanks jimmbo I will. I had looked for a four blade from Quicksilver in aluminum but all I found was their Nemesis and that only for lower horsepower configurations.

 

[Sea Rider]

You haven't posted your achieved wot rpm range as usually loaded with current installed prop, so going for the alum prop or even with 2 less pitch will be a wild guess about its water performance. You have the starter prop installed must go from there if wanting maximizing other prop to suit your boating needs.

Happy Boating

 

[QBhoy]

Hi

Firstly can I say that the old “if I hit the bottom with the stainless prop, it will damage my gearbox” thing is a long since gone issue these days.
Most and certainly your prop and drive will have a flo torque sacrificial hub in it. This is designed to give way well before your gearbox will get damaged. Usually if a stainless lightly touches bottom you might get a wee scuff or dink in it at worse. The same incident with an ally prop will wreck it completely sometimes.

Secondly the good news (if you want to go to ally) is that the prop you have just now is basically just a shiny version of a standard black max ally prop. It’s often the case that the same pitch black max will outperform the vengeance. Nothing useful about them other than for show, in my opinion. Keep the same pitch I’d say, if all is well with your numbers just now.

 

[Texasmark]

Hi

Firstly can I say that the old “if I hit the bottom with the stainless prop, it will damage my gearbox” thing is a long since gone issue these days.
Most and certainly your prop and drive will have a flo torque sacrificial hub in it. This is designed to give way well before your gearbox will get damaged. Usually if a stainless lightly touches bottom you might get a wee scuff or dink in it at worse. The same incident with an ally prop will wreck it completely sometimes.

Secondly the good news (if you want to go to ally) is that the prop you have just now is basically just a shiny version of a standard black max ally prop. It’s often the case that the same pitch black max will outperform the vengeance. Nothing useful about them other than for show, in my opinion. Keep the same pitch I’d say, if all is well with your numbers just now.

"Most and certainly your prop and drive will have a flo torque sacrificial hub in it."
Hoorah!!!! Back to the days of the "Drive Pin" props.......er ah "Shear Pin", so named because every time you are in a tight, like on the windward side if rip rap and need your propulsion.....oops, the Shear Pin sheared because the Aluminum (back then were no SS props) prop hit a rock with my trying to save my boat from the rocks.

I'll take the time tested pressed in rubber insert that slips when an obstacle is contacted and self resets when the engine is returned to idle or N gear and then the drive process is continued as before.

Only reason for the new hub is to suit dealers in having a few props on the shelf with different splined drive hubs to fit an array of applications, not to favor the boater!!!!!!!!!!!!!!! BTDT and it ain't fun!!!!!!!!!!!!

 

[Cortes100]

. I had looked for a four blade from Quicksilver in aluminum but all I found was their Nemesis and that only for lower horsepower configurations.

I see adds on line that say these props are for 135hp and less. That seems weird since I have both a Nemesis and Spitfire (Quicksilver and Mercury). Have a 19P and 21P. On the box it clearly states if fits Alpha and Bravo drives with engines up to 300hp.
I only have both since I was trying to find the right pitch/prop for my application. Both handle well, no prop wash, pull very good on the bottom end, and speed isn't an issue. Have hit 45mph on GPS without WOT.