Reply
 
Thread Tools Display Modes
 
Old 03-30-2015, 04:09 AM   #1
Member
 
Chubasco88's Avatar
 
City: Melbourne, Victoria
Country: Australia
Vessel Name: Gypsy
Vessel Model: Island Gypsy, Hull #56
Join Date: Mar 2014
Posts: 8
Island Gypsy 32 Propellor Size

Greetings from DownUnder.

I have a 32 Island Gypsy and need some help with a propellor size for my vessel. Running a Ford Lehman SP135 so I have bags of power but cannot get past 7 knots at WOT at 1900 RPM.
.
Does anyone know of a suitable prop size that will help me reach 8 knots?

Those in the know say I need larger diameter prop. Current unit is 22" in diameter. Gearbox is a Borg Warner velvet drive unit at 2.01:1 reduction.

Your help would be appreciated

Cheers
Chub88
__________________
Advertisement

Chubasco88 is offline   Reply With Quote
Old 03-30-2015, 07:14 AM   #2
Hospitality Officer
 
Andy G's Avatar
 
City: Pittwater
Country: Australia
Vessel Name: Sarawana
Vessel Model: IG 36 Quad Cabin
Join Date: Sep 2010
Posts: 1,557
Hi & welcome to the forum.

I am no expert on this however I think a bit more information would help.

Is it a three or four blade prop, and do you know the pitch.

If the boats WOT is 1900rpm something is not right. The Lehman's are usually rated to about 2500+ rpm.

You need to ascertain why your WOT is so low , IMHO.
__________________

Andy G is offline   Reply With Quote
Old 03-30-2015, 10:54 PM   #3
Veteran Member
 
overgill's Avatar
 
City: boston
Country: us
Vessel Name: Altair
Vessel Model: Island Gypsy
Join Date: Oct 2013
Posts: 45
Chub

I also have a 32 IG and just had to go through the pain of selecting a new prop
all 1700 $ worth of pain. My set up other than the same boat is quite different I am running a 360 Cummings with I believe a 1.1 to 1 gear. The prop is 4 blade 23x23. I run 7-8 at 1400 and if I run it up to the max 2600 it will do about 14.
I realize this is not apples to apples but like Andy points out without more info its hard to make any assesment. Your max rpm of 1900 would say you are over pitched but your max speed of 7 is saying your under pitched. Verify the ratio of the gear and double check the prop diameter and pitch.
__________________
overgill
overgill is offline   Reply With Quote
Old 04-01-2015, 12:12 AM   #4
Veteran Member
 
overgill's Avatar
 
City: boston
Country: us
Vessel Name: Altair
Vessel Model: Island Gypsy
Join Date: Oct 2013
Posts: 45
sorry thats a 260
__________________
overgill
overgill is offline   Reply With Quote
Old 04-01-2015, 12:54 AM   #5
Veteran Member
 
islandgypsy's Avatar
 
City: Fort Pierce, FL
Country: USA
Vessel Name: Dot Calm
Vessel Model: 1982 32 Foot Island Gypsy Sedan
Join Date: Feb 2015
Posts: 59
Send a message via Skype™ to islandgypsy
What year is your IG? Looks very similar to mine which is a 1982 Sedan model.
I am using a Stainless steel prop which is 1.5 '' diameter. My cruising speed at no current is 7.5 knots powered by a single Ford Lehman V-6 120 horse engine.

Wish I could be more help but would love to learn more about your IG.
Rick
islandgypsy is offline   Reply With Quote
Old 04-01-2015, 12:57 AM   #6
Veteran Member
 
islandgypsy's Avatar
 
City: Fort Pierce, FL
Country: USA
Vessel Name: Dot Calm
Vessel Model: 1982 32 Foot Island Gypsy Sedan
Join Date: Feb 2015
Posts: 59
Send a message via Skype™ to islandgypsy
Forgot to mention that my prop is a THREE blade.
islandgypsy is offline   Reply With Quote
Old 04-01-2015, 07:44 AM   #7
TF Site Team
 
dwhatty's Avatar
 
City: Home Port: Buck's Harbor, Maine
Country: USA
Vessel Name: "Emily Anne"
Vessel Model: 2001 Island Gypsy 32 Europa (Hull #146)
Join Date: Sep 2008
Posts: 2,730
FWIW, the prop that was OEM on our boat with a 330 Cummins is a four blade 25" X 19". Uses a bronze reducer bushing as the prop is for a 2" shaft and our IG has a 1 3/4" shaft. There is a four blade spare on the boat that is 24 X 20 with a 1 3/4 shaft dia.
__________________
David Hawkins
Deer Isle, Maine
dwhatty is online now   Reply With Quote
Old 04-01-2015, 02:26 PM   #8
Veteran Member
 
overgill's Avatar
 
City: boston
Country: us
Vessel Name: Altair
Vessel Model: Island Gypsy
Join Date: Oct 2013
Posts: 45
It is amazing the variables from boat to boat, three blade four blade,diameter and pitch all over the place. I don't even want to know what a SS prop that size would cost. I have 1 1/2 inch shaft it seems the newer IGs went to a 1 3/4 have to assume that was to accommodate the 220 Cummings in the newer 32 IGs I have a 260 Cummings in my 1990 its not original it was installed in 2000. You would think with the same hull that there would be some consistency. Gear ratio would be the only game changer. If you are talking about cruising at hull speed even horse power should not significantly change prop dimensions.

Just babbling but it is interesting to note the differences.
__________________
overgill
overgill is offline   Reply With Quote
Old 04-21-2015, 09:12 PM   #9
Member
 
Chubasco88's Avatar
 
City: Melbourne, Victoria
Country: Australia
Vessel Name: Gypsy
Vessel Model: Island Gypsy, Hull #56
Join Date: Mar 2014
Posts: 8
IG 32 Prop Size.

Hi All,

Just to bring you up to speed on the prop issue.

1. Prop removed and checked by the experts. It is a 22 x 16 3 blade unit on a 1.5" shaft. This is the same size quoted to me by several Aussie prop re-sellers.

2. The governors on the Lehmann were checked and found to be ok.

3. Oil change carried out on the BW Velvet drive.

4. Prop re-installed and coated with Propspeed.

5. Hull antifouled and returned to water.

6. Fuel filters checked and all ok. No water and no black death in the fuel.

Three days after returning to the pen I had an opportunity to do a test run. Conditions were ideal, very little wind and calm seas off the marina.
The results :

1700 RPM = 6knts
2000 RPM = 7knts
2200 RPM = 8.1 knots
2350 RPM = 9 knots
2500 RPM = 9.5 knots (WOT)

All readings were taken from the Chartplotter as SOG.

So watch this space.

Cheers and thank you all for the input.

Chub88
Chubasco88 is offline   Reply With Quote
Old 04-21-2015, 10:04 PM   #10
Guru
 
BruceK's Avatar
 
Join Date: Oct 2011
Posts: 7,556
Malcolm/Chubasco88, it sounds like you are making good progress. Could you post your hull number, it`s on the makers plate, mine is located above the windscreen if that helps.
__________________

__________________
BruceK
Island Gypsy 36 Europa "Doriana"
Sydney Australia
BruceK is offline   Reply With Quote
Reply

Thread Tools
Display Modes

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





All times are GMT -5. The time now is 08:31 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012