Hatteras 53 MY 1981 Prop question

[Dragonten]

I need some advice on props. The boat currently has four bladed Dyna Quad-X - 28 X 31 (Diameter & Pitch) Nibral propellers. Their is also a spare set of bronze props under the stateroom bed. I don't know their pitch or diameter yet. What is the difference between Nibral and Bronze? How does the size of these props compare to others who have 53 MY? Boat is powered with 8V71Ts. I was advised by the surveyor that they should be rebalanced/conditioned and was wondering about the bronze spares as alternative.

Thanks,

Mark

 

[jim rosenthal]

Most propellers (all I've ever seen) have the pitch and diameter stamped on the hub. Might be the side facing down, though.

As far as material, IIRC Nibral (nickel-aluminum bronze alloy) is stronger than bronze, and costs accordingly.

 

[Scarlett]

Mine are 28 x 31 same as yours. John

 

[SKYCHENEY]

My originals were 28x32. I ended up taking pitch out to get to rated WOT at load. Ended up at 28x28.5

 

[Pascal]

Nibral is stiffer. Less flex at the tip of the blade in high hp applications. When I repowered my 53 the prop shop said it would be an overkill for my boat and recommended bronze. It turned out the set of spare I had was nibral and only an inch of pitch off. They were able to adjust the pitch

 

[Dragonten]

Thanks All. I talked to a prop shop and they said that Nibral is more expense and usually better.

John, just curious can you share your cruise and WOT performance?

Mark

 

[Captain Ralph]

I used to compare Nibral / Bronze like outboard wheels; stainless / aluminum.
The thinner & stronger stainless (nibral) was where to find some performance. The thicker and cheaper aluminum (bronze) was always just a good prop to use and cheap to repair.

I can not afford to run much at performance speeds. I have a set of each material. At hull speed, there is no difference. I can not tell you at wot if there is a difference. Just wack one up,,,,, there is a difference $$..

 

[cww]

My 1981 with 8v71ti's are 28x31 which are the OEM factory size. I am sure the later boats with the "bigger" (smaller, but higher horsepower) engines have larger pitch props, and the boats with the "smaller" (actually same size, but non-turbo) engines have less pitch. With your model year you will have the same engines as me, and the 28x31 are the correct size.

 

[rsmith]

Nibrals because of the alloy is much more susceptible to electrolysis. Major damage cannot be repaired like pure bronze. Also I’ve heard that your most likely to do more damage to driveline and transmission components in a hard grounding because of the stronger props. Both my sets are bronze. I run enough hours that I run the pitch out of them every couple years.