Cruisers Forum

Join CruisersForum Today

Thread Tools Rate Thread Display Modes
Old 25-06-2015, 20:58   #1
Registered User
Sailorman Ed's Avatar

Join Date: Jun 2010
Boat: Polynesia 40/42
Posts: 664
Images: 15
Send a message via Skype™ to Sailorman Ed
3 blade props on SD20?

My 12,000 lb cat came with 3 blade props on the SD20 powered by 2GM20FC engines. The spare prop is a 15 x 12 so I expect the ones on there are the same. While motorsailing, no problem but when motoring only, one engine is working too hard and when sailing, the 3 blades seems to be slowing me down. I noticed that originally the SD20 came with 16 x 11 or 18 x 12 2 blades. We will be hauling out later this summer, should I consider switching back to 2 blades in preparation for full time cruising?
Attached Thumbnails
Click image for larger version

Name:	3 blade.jpg
Views:	75
Size:	154.3 KB
ID:	104252  
Sailorman Ed is online now   Reply With Quote
Old 26-06-2015, 03:27   #2
Registered User
Dulcesuenos's Avatar

Join Date: Dec 2010
Location: Florida Keys, Bahamas Bound
Boat: 38' French Cat
Posts: 2,652
Images: 4
Re: 3 blade props on SD20?

Not sure why or what you mean about one engine is working too hard? We have same eng and drives w the two bladed props.
What is your performance and consumption like motoring? And any comparative data to other cats like yours w 2 bladed set ups?
Our 38 Athena motors in calm conditions 6 knots at 2500 we avg 2/3 gal per hour at this cruise . 4.8 on 1 eng. Going to 3000 rpm we gain maybe a knot but consumption doubles.
Not sure where you are but it seems we tend to motor more then sail. If motoring perf is great. Id keep the 3 blades unless they are killing your sailing.
Another fyi we gain half a knot when sailing w drives in neutral. They do hum a bit more and if it's lobster or crab season we keep them locked in gear to prevent snags. Folders may be your best bet.

Sent from my LG-LS980 using Cruisers Sailing Forum mobile app
Dulcesuenos is offline   Reply With Quote

3 blade

Thread Tools
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
Will these 2 different props fit Yanmar SD20? Wanderlust Propellers & Drive Systems 6 30-10-2015 13:18
For Sale: Volvo 2 blade folding props (2 of them) Rodney Classifieds Archive 0 05-08-2012 10:44
For Sale: Two Max Props for SD20 carpe vita Classifieds Archive 5 24-11-2011 14:40
Yanmar 30, SD20 and Props imagine2frolic Propellers & Drive Systems 5 01-01-2011 09:45
WTB: Stock 3-Blade Props for Yanmar SD30 quartersplash Classifieds Archive 0 27-07-2009 20:19

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 20:35.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.