Prop Material Pros and Cons

[wakeup]

I currently have an aluminium prop on my 5.0l Alpha 1. By replacing it with a stainless steel prop will the performance be improved just becasue of a change of material or does having a ss prop allow for a greater degree of blade angle and therefore performance?

I would be interested in your oppinions since an ALu prop seems to be around £120 whereas a SS prop seems to be closer to £250. Would i get better performance but greater fuel consumption. (No S*****N posts please, I think it's been done to death)

What do you think?

 

[hlb]

Yes I also need new props, there wareing away. And no I cant send them to some wonderous mender cos there F**cked, knackererd. Past there sell by date, not bent, but no mettal left in them. Volvo Tamd200's P35. What size props?? Dont guess. Sensible replys only please. And if I hear any more of the Soltron crap, I'll be sick, All over you. Be warned. Oh and where best posible price please as the boats got to be draged out of the water again to fit the f******ing things that should have gone on last time round.

No one can force me to come here-----------
----- I'm a Volunteer!!!

Haydn

 

[lanason]

what happened to that familly on that live-a-board boat. Wasnt that in your marina - ???
Do you know ??
Adrian
p.s. so why if you dont want to talk about s*****n do you mention it - red burgee to a bull and the like. )

Don't call me "Sandra"
Cleopatra - yellow hull called Court Jester. Have you seen her ?

 

[wakeup]

The familly stil seem to be there. Vince seems to have spent the last month painting and doing up the exterior of the boat. For whom he is making it acceptable i don't know, but if he has been singled out because someone doesn't like the aesthetics of his boat I think that is very unfair becasue there are plenty of other livaboards in much worse conditions in the marina. I hope they get to stay.

 

[Guest]

Ally is relatively weak, and so the blades need to be thick to give them sufficient strength compared to stainless. Effectively, if they're not rigid enough, the load on them shortens the pitch. As stainless is much stiffer, the same pitch S/S prop will not deflect so much under load, and so 'retain' its pitch, accounting for some of the performance improvements. Also, because the material is thinner, the leading edges can be sharper, and hence more efficient, and the prop can also be manufactured to a more complex shape.

I've run a variety of stainless props. My personal favourite for the Merc leg was an Attwood Ballistic - very good performance, and almost impossible to induce ventilation in turns...

Now if only someone did stainless duoprops for Volvo outdrives (other than Volvo), I'd be a happy man...

 

[wakeup]

Thanks Graham

 

[Guest]

Hi,
I know I'm a bit late with this reply, but recently we were caught in a similar dilemma.
We were advised to use Stainless Steel props on our new tripper speedboat out in Thailand. The theory being that Stainless Steel will give you 10%-15% percent extra efficiency over Aluminium but at more than twice the price. Being a commercial enterprise, that 10 to 15 percent was worth having at 250+ litres of Petrol a day!!
The 'kick back' is that the inherent extra strength of stainless steel will transmit all the way along the drive train, should you hit any uncharted rocks or obstacles along the way, thus risking taking out the engine, gearbox and shaft as well!!
Aluminium Props are softer so would absorb the impact better at the price of a new prop, but would save you your engine potentially.
Our decision?? in the end, Stainless Steel!!( and a great deal of attention to the navigation of our planned, tried and GPS plotted routes).
Enjoy the season,
Peter.

 

[wakeup]

Thanks Peter,

That's certainly an angle I hadn't heard before with respect to ally props protecting the drive and gear box. Very relevant to my circumstances as the reason I am changing the prop is that I have somehow bashed the ally one but was lucky that I didn't damage the bearings or gear box. Perhaps that's why because I had an ally prop. Have decided to go for an ally replacement as I don't do enough hours to pay back the difference.

Cheers

Shaun