Reply
 
Thread Tools Display Modes
 
Old 04-22-2016, 03:47 PM   #1
Senior Member
 
Capstan's Avatar
 
City: Exumas
Country: Bahamas
Vessel Name: Bad Monkey
Vessel Model: Gulf Star 43
Join Date: Jul 2015
Posts: 134
Fuel usage

Anyone have any burn rates for a pair of 6-354's in the Gulfstar 43?
Would be interested to see how mine compares.

Capstan
__________________
Advertisement

Capstan is offline   Reply With Quote
Old 08-16-2016, 11:48 AM   #2
Newbie
 
City: Jacksonville FL
Country: USA
Join Date: Aug 2016
Posts: 1
Diesel burn

I have a 73 Gulfstar 43 with twin Perkins 135s. Running one screw at 1500 I'll get 6-8 kts and burn 3.5 gph.
HOWEVER, running two screws, each at 1500, I'll get 8-10 kts and burn 2.5 gph.
Yes, I burn less diesel on two screws than I do one...
I gave up trying to figure out torque curves and angle of the rudders and just accept that Lucky wants to run on two screws
__________________

riverfrontauthor is offline   Reply With Quote
Old 08-16-2016, 08:27 PM   #3
Senior Member
 
Lobstah's Avatar
 
City: Dunedin, Fl
Country: USA
Vessel Name: T/T Whistful
Vessel Model: Boat US 12' Inflatable
Join Date: Jul 2011
Posts: 216
So you're getting 4kts out of 1 to 1.25 gal of fuel... sounds pretty good.
Lobstah is offline   Reply With Quote
Old 12-31-2016, 07:04 PM   #4
Senior Member
 
Capstan's Avatar
 
City: Exumas
Country: Bahamas
Vessel Name: Bad Monkey
Vessel Model: Gulf Star 43
Join Date: Jul 2015
Posts: 134
Quote:
Originally Posted by riverfrontauthor View Post
I have a 73 Gulfstar 43 with twin Perkins 135s. Running one screw at 1500 I'll get 6-8 kts and burn 3.5 gph.
HOWEVER, running two screws, each at 1500, I'll get 8-10 kts and burn 2.5 gph.
Yes, I burn less diesel on two screws than I do one...
I gave up trying to figure out torque curves and angle of the rudders and just accept that Lucky wants to run on two screws

Sorry it's been a while but:
When I took the boat to Florida. Very rough conditions. 12' + in the Gulf Stream but the worst was from New providence to Chubb 4' to 8' 3 points off the Stbd bow. Wet wet wet
Anyway the fuel usage for 24hours (this was over a 3 day cruise. Roughly 8 hrs running a day) came out to approx. 180g. (dirty Bum and props)
We were running hard. The engines did not miss a beat. Considering the boat probably hasn't done anything like that in the last 15 years. It was impressive.
In Lauderdale I had the Fuel pumps professionally overhauled. Props and bottom done.
On the run back conditions were a lot smoother to say the least and the fuel burn:
running at 1,600 for most 2/3 of the way and 1,800 for the other 1/3
Approx. 83g
So that is pretty well spot on what you are getting.
Very happy indeed!
__________________
Capstan


"Eagles may soar, but monkeys don't get sucked into jet engines!"
Capstan is offline   Reply With Quote
Old 01-04-2017, 11:33 PM   #5
Member
 
Join Date: Oct 2011
Posts: 5
Capstan,
I'm buying a 1973 Gulfstar 43 MKI and was wondering if you know for certain the capacity of the fuel tank? I've heard 200 and 300 gallons. Just wondering if you knew for sure. Prior owner of my boat says it get 2.2 GPH both engines at 1800 rpm (9 Knots) and genny running.
Thanks
mkh8911 is offline   Reply With Quote
Old 01-05-2017, 09:10 AM   #6
Veteran Member
 
City: Chicago
Country: United States
Vessel Name: Sea Jay
Vessel Model: Non Trawler ;-) Ask me if it matters LOL
Join Date: Jun 2016
Posts: 81
If you can get a clean measurement of the tanks to determine approximate square inches, you can narrow that down. 231 cubic inches - 1 gal US. Let's hope for rectangular tanks!
Gmarr is offline   Reply With Quote
Old 01-05-2017, 09:43 AM   #7
Guru
 
BandB's Avatar
 
City: Fort Lauderdale
Country: USA
Join Date: Jan 2014
Posts: 9,058
Quote:
Originally Posted by mkh8911 View Post
Capstan,
I'm buying a 1973 Gulfstar 43 MKI and was wondering if you know for certain the capacity of the fuel tank? I've heard 200 and 300 gallons. Just wondering if you knew for sure. Prior owner of my boat says it get 2.2 GPH both engines at 1800 rpm (9 Knots) and genny running.
Thanks
You can't go by what anyone says. You have a couple of ways of approximating or measuring depending on how precise you want to get. One is to measure the physical dimensions. Another is to empty into some other tank or system and see what it takes to fill it. You can't be sure what was initially put in the boat and, even if you were, it may well no longer be the original tank.

For approximation you might use the guages and sight glasses if there are any and get it to half empty/full and that would probably let you know if it's closer to 200 or 300. You have another issue too and that is usable capacity based on pickup location and type and based on condition of tank and any issues inside the tank, such as debris or sludge or water, all which would become issues if you tried to use it all. I know someone who recently made a purchase in your situation and his solution was to have a fuel company come polish his fuel and clean the tank and at the same time tell him exactly how much fuel it took to fill the tank. It was an odd number but actually greater than the stated capacity as apparently the builder had been conservative in stating the capacity. Some are and will call a 312 gallon tank 300, but then others work on the "close enough" principle and call 285 gallons 300.
BandB is online now   Reply With Quote
Old 01-05-2017, 10:07 AM   #8
Guru
 
City: East Coast
Country: USA
Join Date: Dec 2013
Posts: 1,955
Most fuel tanks will have a label on them stating the capacity. That's one way of knowing.


Unless you have a fuel management system, it's pretty hard to know your accurate fuel burn unless you keep records over a long period. It's really hard to fill your tanks to the same level each time you fuel.


Speed makes all the difference in the world, especially once you exceed "hull speed". Jus a knot or two can double your fuel burn.
WesK is offline   Reply With Quote
Old 01-05-2017, 11:14 AM   #9
Guru
 
City: Carefree, Arizona
Country: usa
Vessel Name: sunchaser V
Vessel Model: DeFever 48
Join Date: Apr 2008
Posts: 5,570
Quote:
Originally Posted by Gmarr View Post
Let's hope for rectangular tanks!
Uh uh. Lets hope for tanks that conform to the hull sides thus optimizing volume drawn vs dead bottom space. Measure the tank's volume when fueling by marking a stick or sight rube at various gallons when filling from empty to full.
sunchaser is offline   Reply With Quote
Old 01-07-2017, 10:49 AM   #10
Senior Member
 
Gulfstar 36's Avatar
 
City: Kent Island
Country: USA
Vessel Name: Sundowner
Vessel Model: Gulfstar 36 MrkII
Join Date: Jul 2012
Posts: 226
The tank on my 36' MrkII trawler conform to the hull as demonstrated in these sounding measurements.

235 topped
225 30
200 29
150 25
100 22
50 16


Quote:
Originally Posted by sunchaser View Post
Uh uh. Lets hope for tanks that conform to the hull sides thus optimizing volume drawn vs dead bottom space. Measure the tank's volume when fueling by marking a stick or sight rube at various gallons when filling from empty to full.
Gulfstar 36 is offline   Reply With Quote
Old 01-07-2017, 11:31 AM   #11
Senior Member
 
Capstan's Avatar
 
City: Exumas
Country: Bahamas
Vessel Name: Bad Monkey
Vessel Model: Gulf Star 43
Join Date: Jul 2015
Posts: 134
Quote:
Originally Posted by mkh8911 View Post
Capstan,
I'm buying a 1973 Gulfstar 43 MKI and was wondering if you know for certain the capacity of the fuel tank? I've heard 200 and 300 gallons. Just wondering if you knew for sure. Prior owner of my boat says it get 2.2 GPH both engines at 1800 rpm (9 Knots) and genny running.
Thanks
Think I posted on your other thread.
300g but no dipstick.
__________________
Capstan


"Eagles may soar, but monkeys don't get sucked into jet engines!"
Capstan is offline   Reply With Quote
Old 01-07-2017, 08:01 PM   #12
Guru
 
Capt.Bill11's Avatar
 
City: Sarasota/Ft. Lauderdale
Country: USA
Join Date: Apr 2014
Posts: 4,994
Quote:
Originally Posted by WesK View Post
Most fuel tanks will have a label on them stating the capacity. That's one way of knowing.
I wish that was true.
__________________

Capt.Bill11 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 03:08 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