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 Post subject: prop information
PostPosted: 21 Oct 2019 07:07 
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Tactictian

Joined: 16 Jan 2019 08:52
Posts: 103
I will be heading south from Cobbs Marina in a few weeks after I attend to the bottom and make preparation for the trip. I am interested in getting a spare prop to replace the Flexofold for the journey which will be ICW mostly so I want to have a fixed prop for performance while motoring. What is a good match for the Westerbeke and does anyone have any suggestions for a good used prop or a supplier in the Norfolk area. I will have a car on my arrival so pick up won't be a problem. I am new to the boat so I don't know all the specs regarding shaft size, pitch and diameter so I could shop here in Canada before I leave.


 
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 Post subject: Re: prop information
PostPosted: 21 Oct 2019 15:24 
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Skipper

Joined: 09 Aug 2017 15:35
Posts: 725
Location: Maine/USVI
I would appreciate a 3 blade fixed as well. This 2 blade folding prop, I dunno. Had one on my Pearson 10M and it worked O.K., but if I'm going down the ICW I want immediate and appreciable bite. I have the W50.


Last edited by Maineiac on 21 Oct 2019 16:46, edited 1 time in total

 
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 Post subject: Re: prop information
PostPosted: 21 Oct 2019 16:23 
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Tactictian

Joined: 16 Jan 2019 08:52
Posts: 103
When I bought the boat in January and took delivery in April the performance of the engine and prop was OK considering it had been in the water at the time of purchase and I was pleasantly surprised by the Flexofold while sailing I found the reverse performance some getting used to. As I need a spare prop anyway I thought it wise to swap it now while on the hardstand and get better grunt for the long motoring trip. I am at a loss though as to a two or three blade fixed prop and the Diam and pitch for the Westie 50. So I am hoping for a few leads from the owners on this forum. I am sure it has been hashed out before.


 
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 Post subject: Re: prop information
PostPosted: 21 Oct 2019 16:47 
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Skipper

Joined: 09 Aug 2017 15:35
Posts: 725
Location: Maine/USVI
Yes yes, W50. I'm so wrapped up with ST 60 instruments and replacing Airmar transducers, etc. I'm making myself confused.


 
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 Post subject: Re: prop information
PostPosted: 24 Oct 2019 09:28 
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Skipper

Joined: 29 Dec 2006 09:38
Posts: 656
Props have been hashed out here before. When I had the W50 with the Campbell Sailor prop from the factory, the system was grossly overpitched. I believe this contributed to the early (4500 hrs) demise of my W50. Impossible to reach max RPM, and lugged at 1800. I moved to an AutoStream (Austrailian, Stainless steel, Sold by Martec here in the US) feathering, externally adjustable three blade which I have used on both the W50 and my 3JH Yanmar replacement. Because the pitch is externally adjustable I have tweaked it with each engine torque and sometimes with loads (I was travelling a lot heavier during my years of cruising in Central America than now and pitch needs change). I probably have 20K miles and 20 years on it and could not be happier. Probably costs less than the Max Prop (which I did not like due to fragile, complex construction of more malleable, bendable bronze) and maybe a bit more than than Flexofold which I did not see as an alternative at the time. But the key, to me is to be able to externally adjust the pitch to “tune” prop bite to the actual torque of your engine and the drive characteristics of your loaded boat. No one is going to be able to actually compute this with much accuracy off the boat—so to get it right can be costly if you have to haul the boat, remove the prop, re pitch it and splash the boat again. I am a former delivery skipper and my experience is that most auxiliary drive systems are overpitched or underpitched—while running this way will not bother most folks, it can be a long term problem for the longevity of your engine.


 
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 Post subject: Re: prop information
PostPosted: 26 Oct 2019 07:45 
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Tactictian

Joined: 16 Jan 2019 08:52
Posts: 103
Thanks for the info. I had seen reference to the improper recommendations leading to engine fatigue in past posts as well as numerous other discussions. I am happy enough with the Flexofold that came with the boat but I have limited experience with it as I only took delivery and steamed the boat two days up to Cobbs for a haul out and am only returning to take the boat down the ICW. I wanted a fixed prop for the trip south for maximum motoring performance and will swap back to the Flexo when I haul for the summer in Florida to begin sailing next winter. I was interested in a general consensus as to diam,pitch, shaft size, three or two blade etc. from the forum general populous.


 
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 Post subject: Re: prop information
PostPosted: 26 Oct 2019 20:45 
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Skipper

Joined: 14 Jul 2012 20:36
Posts: 495
Location: Norfolk, Va
With the W50 I was running a 17-13-2B-RH Flexofold. The tranny 1:2.14, shaft 1" SAE. It was slightly over pitched, which I liked. I did replace the motor to a Beta 35 with same tranny. New prop is a Flexofold 17-11-3B, jury still out. Only have two hours on it.

_________________
Hull #208, Puff Card
Southern Chesapeake Bay


 
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 Post subject: Re: prop information
PostPosted: 27 Oct 2019 18:33 
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Tactictian

Joined: 16 Jan 2019 08:52
Posts: 103
Mine is the flexfold 3 blade so I guess I'll just stick with that and see how I make out. I am planning on launching around the fifteenth of November to head south.


 
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 Post subject: Re: prop information
PostPosted: 27 Oct 2019 19:21 
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Skipper

Joined: 14 Jul 2012 20:36
Posts: 495
Location: Norfolk, Va
Keep a lookout for Puff Card we'll be leaving near the same time from Norfolk.

You can try this calculator and see what you get. Do you know what you got?
https://www.vicprop.com/displacement_size.php

_________________
Hull #208, Puff Card
Southern Chesapeake Bay


 
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 Post subject: Re: prop information
PostPosted: 05 Mar 2020 21:25 
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Skipper

Joined: 29 Dec 2006 09:38
Posts: 656
If you are hitting hull speed at 2500 on a 3000 max rpm engine, the books say you are over pitched and lugging your engine that is why added rpm does not give you more speed. In flat water, max rpm of the engine should equal hull speed. Otherwise the engine is slightly lugging at 2500. Diesels (according to research at Yanmar) should run most of the time at 75%-80% of max rpm which would generally be somewhere around that percent of hull speed. Reaching hull speed at lower rpm with save fuel and not be good for the long term life of your diesel. I believe this is covered in several books: Nigel Calder is one of them. FWIW.
Ray Durkee
T37 #373


 
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