Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 01-03-2020, 16:15   #1
Bailing as fast as I can.
 
GILow's Avatar

Join Date: Sep 2008
Location: Adelaide, South Australia
Boat: Swanson 42
Posts: 6,531
Engine to shaft coupling, different sizes

Hi all,

My new engine has a smaller diameter on the output flange than the original engine.

The current Polyflex coupling is very old, so I was intending to replace it anyway.

Polyflex can make a custom adapter to attach to the new coupling to match the sizes, it I thought I should see if there are any products that people know of that address this particular issue.

Current shaft flange has a 4.25 inch bolt circle diameter, the new engine has a an 82.5 mm bolt circle diameter.

I have HEAPS of room thanks to the much smaller engine, so the adapter can be as thick as needed (within reason).

Any recommendations?
__________________

__________________
Count-down has commenced.
GILow is online now   Reply With Quote
Old 01-03-2020, 19:02   #2
Moderator
 
JPA Cate's Avatar

Join Date: Nov 2011
Location: aboard, cruising in Australia
Boat: Sayer 46' Solent rig sloop
Posts: 18,734
Re: Engine to shaft coupling, different sizes

If they can make the custom adapter for you, go for it! Make the installation as simple as possible and finish it up and tell us all how it went! No over-thinking!

Ann
__________________

__________________
Who scorns the calm has forgotten the storm.
JPA Cate is offline   Reply With Quote
Old 01-03-2020, 20:10   #3
Bailing as fast as I can.
 
GILow's Avatar

Join Date: Sep 2008
Location: Adelaide, South Australia
Boat: Swanson 42
Posts: 6,531
Re: Engine to shaft coupling, different sizes

Quote:
Originally Posted by JPA Cate View Post
If they can make the custom adapter for you, go for it! Make the installation as simple as possible and finish it up and tell us all how it went! No over-thinking!



Ann


Overthinking...? Me?

Let me think about that and Iíll get back to you.

But, Beta Marine Australia are very happy about the Polyflex couplings and recommend them and one other sort to clients.
__________________
Count-down has commenced.
GILow is online now   Reply With Quote
Old 01-03-2020, 21:28   #4
Registered User

Join Date: Nov 2013
Location: Nice, France
Boat: Hunter Marine 38
Posts: 875
Re: Engine to shaft coupling, different sizes

If you have the money to spend on a Sigma drive the this is the moment. They will compensate for +- 3į and transmit thrust.
sailormed is offline   Reply With Quote
Old 01-03-2020, 21:36   #5
Registered User
 
Fore and Aft's Avatar

Join Date: Jan 2015
Location: Gympie
Boat: Volkscruiser
Posts: 1,185
Re: Engine to shaft coupling, different sizes

GiLow Polyflex is the best. You can go to their workshop in Redcliffe and actually speak to the guys making the mounts and adapter. They are so good a few years ago I was passing through Redcliffe very early in the morning and although the office was closed the workshop had my mounts waiting for me.
Cheers
Fore and Aft is offline   Reply With Quote
Old 01-03-2020, 22:11   #6
Bailing as fast as I can.
 
GILow's Avatar

Join Date: Sep 2008
Location: Adelaide, South Australia
Boat: Swanson 42
Posts: 6,531
Re: Engine to shaft coupling, different sizes

Quote:
Originally Posted by sailormed View Post
If you have the money to spend on a Sigma drive the this is the moment. They will compensate for +- 3į and transmit thrust.


Thatís a good point. I did seriously consider it, and it would be easy to fit, but in the end I felt that the install and alignment are so simple in my boat that adding such a drive would be adding potential problems rather than solving them. (Though I believe they are very reliable.)
__________________
Count-down has commenced.
GILow is online now   Reply With Quote
Old 01-03-2020, 22:12   #7
Bailing as fast as I can.
 
GILow's Avatar

Join Date: Sep 2008
Location: Adelaide, South Australia
Boat: Swanson 42
Posts: 6,531
Re: Engine to shaft coupling, different sizes

Quote:
Originally Posted by Fore and Aft View Post
GiLow Polyflex is the best. You can go to their workshop in Redcliffe and actually speak to the guys making the mounts and adapter. They are so good a few years ago I was passing through Redcliffe very early in the morning and although the office was closed the workshop had my mounts waiting for me.

Cheers


Thatís good to know, thank you. I have always suspected that they are good, but itís good to hear it from a trade pro.
__________________
Count-down has commenced.
GILow is online now   Reply With Quote
Old 02-03-2020, 19:58   #8
Registered User

Join Date: May 2009
Location: Belfast, Maine
Boat: Morgan, OI, 33'
Posts: 94
Re: Engine to shaft coupling, different sizes

Here's a thought: Remove the rubber from the old coupling & duplicate it from a section of old tire!
Disailor is offline   Reply With Quote
Old 02-03-2020, 20:34   #9
Bailing as fast as I can.
 
GILow's Avatar

Join Date: Sep 2008
Location: Adelaide, South Australia
Boat: Swanson 42
Posts: 6,531
Re: Engine to shaft coupling, different sizes

Quote:
Originally Posted by Disailor View Post
Here's a thought: Remove the rubber from the old coupling & duplicate it from a section of old tire!


Very... um... cost effective.

Iíve just been having a laugh with the Polyflex rep after I realised my tired old prop shaft flange was troubling his sense of the aesthetic more than any particular engineering concern.

I think Iíll forward your tyre idea to him and see how much of a reaction I can get.
__________________

__________________
Count-down has commenced.
GILow is online now   Reply With Quote
Reply

Tags
engine, size

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
flexible shaft coupling for short shaft melemakani Propellers & Drive Systems 6 22-12-2015 06:16
can I mix different rudder angle indicator and different autopilots awab Marine Electronics 11 24-04-2013 14:25
Cable Sizes: Different for +ve and -ve? Tday01 Electrical: Batteries, Generators & Solar 9 27-10-2012 19:53
Different Wire Sizes In Bilge Pump Circuit cburger Construction, Maintenance & Refit 37 03-02-2012 06:36
Joining two greatly different wire sizes Roy M Electrical: Batteries, Generators & Solar 34 01-08-2007 10:32

Advertise Here


All times are GMT -7. The time now is 04:06.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.