Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 24-01-2018, 15:56   #1
Registered User

Join Date: May 2015
Location: Sydney
Boat: Folk boat M26
Posts: 13
Propeller advice

Hi, I have a 26’ Folkboat with an 8hp yanmar and offset shaft.
It has a fixed 12” two bladed prop at the moment. I have just seen a Hydralign three bladed feathering prop for sale at a reasonable price.
My question is would this be a suitable change over ?
Cheers Tom
Windward mark is offline   Reply With Quote
Old 24-01-2018, 16:14   #2
Moderator and Certifiable Refitter
 
Wotname's Avatar

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: C.L.O.D.
Posts: 20,301
Re: Propeller advice

The Hydralign three bladed feathering prop will most likely give you better motoring and better sailing performance compared to your existing 2 blade fixed prop ASSUMING
1. The diameter of the Hydralign prop is suitable for your prop aperture (and engine).
2. The rotation is suitable. I guessing your existing Yanmar is either a Y or an S series engine and these require a LH prop while most later engines use a RH prop.

The two main advantages of the Hydralign will be better pitch control (i.e. adjustable pitch) and lower drag when sailing.
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is offline   Reply With Quote
Old 24-01-2018, 16:33   #3
Marine Service Provider

Join Date: Sep 2014
Location: Auckland, NZ
Boat: Compass 790 , 7.9 metres or 26 ft
Posts: 2,803
Re: Propeller advice

Quote:
Originally Posted by Windward mark View Post
Hi, I have a 26’ Folkboat with an 8hp yanmar and offset shaft.
It has a fixed 12” two bladed prop at the moment. I have just seen a Hydralign three bladed feathering prop for sale at a reasonable price.
My question is would this be a suitable change over ?
Cheers Tom
First off I'm not a propellor expert but you need to find out a few things. Is the shaft size & taper the same? Also the the pitch & diameter if it's not an adjustable pitch. The pitch & diameter can be altered by a prop shop but you need to price it first. Small differences in diameter/pitch make a big difference to a Yanmar 8hp. I'm going thru the same process with our Yanmar YSM8. Have already changed props ( it was a gift) but we are over-propped.I am soon to try re-pitching it myself. You know yours is a left hand prop I assume? They are less common. Our replacement is a r/h prop but we are using reverse as fwd. Yanmar rep said that was ok. Our 26ft fin keeler calls for a 12" dia x 7" pitch L/H prop according to the free Vicprop online calculator ( Google it). We have a 1" prop shaft, dont know what the taper & keyway size is but you should measure yor shaft for a start. Hope that points you in the right direction anyway.
Compass790 is offline   Reply With Quote
Old 24-01-2018, 16:56   #4
Moderator and Certifiable Refitter
 
Wotname's Avatar

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: C.L.O.D.
Posts: 20,301
Re: Propeller advice

I should add that like Compass790, I also am not propeller expert and he made some good observations.

After looking at the Hydralign website, it seems their props might work as either LH or RH but it would be good to get confirmation on this aspect.
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is offline   Reply With Quote
Old 25-01-2018, 20:41   #5
Registered User

Join Date: May 2015
Location: Sydney
Boat: Folk boat M26
Posts: 13
Re: Propeller advice

Thanks for the advice, interesting about running the engine in reverse for a right handed prop. Can this be done as a permanent solution with no repercussions?
Windward mark is offline   Reply With Quote
Old 25-01-2018, 20:50   #6
Moderator and Certifiable Refitter
 
Wotname's Avatar

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: C.L.O.D.
Posts: 20,301
Re: Propeller advice

Quote:
Originally Posted by Windward mark View Post
Thanks for the advice, interesting about running the engine in reverse for a right handed prop. Can this be done as a permanent solution with no repercussions?
Generally speaking - no, most gearboxes won't like it.

However occasionally it is possible, see this recent thread
http://www.cruisersforum.com/forums/...on-195457.html
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is offline   Reply With Quote
Old 26-01-2018, 00:09   #7
Marine Service Provider

Join Date: Sep 2014
Location: Auckland, NZ
Boat: Compass 790 , 7.9 metres or 26 ft
Posts: 2,803
Re: Propeller advice

Well the Yanmar rep said I can run using reverse but I'm basing my use of it by examination of the gearbox & clutch drawings & my memory of it ( not to be relied on! ) when I had it apart. This only applies to the Kanzaki gearbox supplied with the YSM8. Re the prop u wanna buy as Wotname has said it's variable pitch so that can compensate for diameter somewhat.Also his suggestion to contact the manufacturer is good as some of the variable pitch props have inserts that can compensate for differing shaft sizes & tapers. Personally I'd love a variable pitch prop, best of all is one you can change whilst in motion. Dreams are free :-)
Compass790 is offline   Reply With Quote
Reply

Tags
propeller, rope

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Advice on Propeller Pitch Adjustment to Match Cruise HP at 3,000 RPM HighFly_27 Propellers & Drive Systems 8 13-05-2015 17:37
Propeller Advice If You Please ! captainzack Propellers & Drive Systems 12 12-09-2012 07:45
Propeller Advice timbenner Propellers & Drive Systems 9 29-09-2010 08:20
New Propeller Advice Alex128 Propellers & Drive Systems 3 27-11-2009 19:07
Who invented the Screw Propeller? GordMay Electrical: Batteries, Generators & Solar 6 13-01-2006 15:15

Advertise Here


All times are GMT -7. The time now is 06:14.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.