I have been researching engine options for my 53 my. In doing so I was working with a reputable prop shop to determine what props would be suited for each desired power package. My Hatteras build sheet says that my boat came with 23x31 4 blade Michigan props. The prop guy can’t figure out why Hatteras used these and didn’t use a lager diameter. He is telling me that the boat should have 28” props. Thought?
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Thread: Prop size
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10-11-2018 12:35 PM #1Senior Member
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- Dec 2014
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Prop size
Pete. 1980 53 my. #575
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10-11-2018 12:53 PM #2
Re: Prop size
Either theres a misprint or you have a prop that cant exist.
You should have a 28" diameter prop.
2" shafts do not fit 23" props. The diameter and hub size would make it outside of the norm.
I know theres a diameter minimum and maximum for each shaft size.Scott
41C117 "Hattatude"
Port Canaveral
I have no idea what the last poster is saying. I don't think he does either.
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Re: Prop size
According to the Michigan Wheel technical catalog a 23 inch diameter wheels can have a 2" max prop shaft with no problem.
The survey report from my last survey says my props are 22 x 23 and I have 2" shafts.
I can see the 23 diameter wheel but that 31 pitch is bit much for a 53 with 8V71's.
I will check my build sheet tonight and also see what the spares are in the bilge.Tim
1979 53' MY Hull #566
KNOW PRESSURE
Hampton, Virginia
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10-11-2018 03:44 PM #4Senior Member
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- Dec 2014
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- 396
Re: Prop size
Here is a pic of my build sheet
Pete. 1980 53 my. #575
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10-11-2018 04:40 PM #5Senior Member
- Join Date
- Jan 2006
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- 827
Re: Prop size
Prop size will depend on the ratio of the reduction gears that were used.
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10-11-2018 04:48 PM #6
Re: Prop size
Just replaced 2 4 blade 26 x 32 with beams. High speed (35 kt vessel)
Also spoke to the acme guys. Was told the minimum they did for our need was 24 or 26 inch on 2" shafts. It's all part of the hub size and stress based on hp.
Its a science now. Less gut and guessing. They make some nice CBC props.
I'm sure they are far more efficient than older designs.Scott
41C117 "Hattatude"
Port Canaveral
I have no idea what the last poster is saying. I don't think he does either.
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10-11-2018 05:36 PM #7Senior Member
- Join Date
- Apr 2008
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- 494
Re: Prop size
An you don't take those Veem''s and Acme's to the propeller blacksmith shops either.
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10-11-2018 07:24 PM #8
Re: Prop size
F no.
Scott
41C117 "Hattatude"
Port Canaveral
I have no idea what the last poster is saying. I don't think he does either.
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10-11-2018 07:27 PM #9
Re: Prop size
Things of beauty
Scott
41C117 "Hattatude"
Port Canaveral
I have no idea what the last poster is saying. I don't think he does either.
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Re: Prop size
I don't know anything about prop sizes and Hatteras yachts in particular. That said, as stated it is more of a science these days and the prop shop makes a huge difference. I went through 4 of them before I found the holy grail of prop work. I have Acme and Veem and the Veems are a thing of beauty for sure. The diameter is limited by how close to the hull that the tips pass - closer equals more noise. The diameter is dictated by the engine loading so that WOT develops the correct RPM, say 2300. The number of blades is usually a tradeoff between faster (less blades) and smoother/quieter (more blades). You get rpm vs speed data and the WOT numbers for both sides and the distance to the hull and a quality shop/vendor can dial in what you need based on your goals. Not all manufacturers/prop series are equal. Some have cavitation problems for instance where a prop can be destroyed from the impact damage at the blade/hub interface. If you ever find a great prop shop that gets your wheels really dialed in, get them drilled for a propsmith or get a proper puller so that the yard doesn't beat the crap out of them and your transmission thrust bearings. Also make sure that they lap the tapers to the proper contact percentage as well.
GeorgeFlorida
2002 Cabo 47
MAN mechanical 800/8's
"You can avoid reality, but you cannot avoid the consequences of avoiding reality"