Reply
 
Thread Tools Search this Thread
 
Old 16 April 2014, 09:52   #11
Member
 
Country: UK - Scotland
Town: Argyll
Make: Tornado
Length: 5m +
Join Date: Sep 2011
Posts: 91
Quote:
Originally Posted by Pikey Dave View Post
inline fuel flow sensors are notoriously inaccurate, especially at low speeds.
They are sufficiently precise (consistent) at high flow rates/speeds for determining efficient boat running setup - for example obtaining optimum engine trim and rev range for fuel economy. They can also highlight problems with the engine or hull that would otherwise go unnoticed.
I had a seam on my tubes that was coming unglued and billowing out at planing speeds but not at rest. I first knew something was not right as the fuel consumption rate was 20% higher for the same cruising speed and load than I was used to.

Depending on the purpose of your boat, I could imagine one burns well under 10% of fuel at low speeds; the rest at high speeds, therefore the accuracy at low speeds is mostly irrelevant.

I wouldn't rely on one for a calculated tank level reading if you are the type of boater to start a trip with anything other than a full tank. If you only ever add the odd few litres here and there, and you are down to the last 1/10th of a tank on the 'gauge', I wouldn't presume there was any fuel left at all!

Having said this, my EP-60r after calibration returns an error of +-1 litre of fuel on 70 litres of use from a 90litre tank through a 100HP outboard. This is an accuracy of +-1.5% and has been within this margin of error over 40 or so trips to the pump. When fuelling the boat on the water I can't judge when the tank is 'full' to within this margin of error anyway. so with proper trip planning and safety margins, the range/duration remaining value calculated using one of these fuel sensors could be useful. I still rely on my Mk1 eyeball fuel level sensor before setting off as I can see inside my tank, and would get level sensor if not, in order to verify tank level.

As with all these gadgets, if you know their limitations, then they can still give useful information, just not perhaps the full picture that you desire.
__________________

__________________
steve-ribnet is offline   Reply With Quote
Old 16 April 2014, 12:50   #12
RIBnet admin team
 
Nos4r2's Avatar
 
Country: UK - England
Town: The wilds of Wiltshire
Boat name: WhiteNoise/Dominator
Make: Ballistic 7.8/SR5.4
Length: 7m +
Engine: Opti 225/Yam 85
MMSI: 235090687/235055163
Join Date: Jul 2005
Posts: 12,645
RIBase
Quote:
Originally Posted by steve-ribnet View Post
They are sufficiently precise (consistent) at high flow rates/speeds for determining efficient boat running setup - for example obtaining optimum engine trim and rev range for fuel economy. They can also highlight problems with the engine or hull that would otherwise go unnoticed.
Same kit on mine-EP60R sender via NMEA 2k network and displayed on an HDS7.

I agree-it's good enough to tell me if I'm cruising at the optimum speed. I've got mine set to miles per litre.
I've also got the (US) GPH figures on Smartcraft and they aren't that far removed when I've bothered to work it out.

It only becomes obviously wrong at WOT and displacement speeds.
__________________
Need spares,consoles,consumables,hire,training or even a new boat?

Please click HERE and HERE and support our Trade Members.

Join up as a Trade member or Supporter HERE
Nos4r2 is offline   Reply With Quote
Old 16 April 2014, 15:47   #13
Member
 
Country: UK - England
Town: Margate / Ramsgate
Boat name: Ballistic
Make: Ballistic
Length: 7m +
Engine: Yam HPDI 250
Join Date: Feb 2002
Posts: 2,835
Quote:
Originally Posted by Nos4r2 View Post
I've got mine set to miles per litre.

Who you kidding... Litres per mile.

Got the ballistic out of the field yet?
__________________
Daniel is offline   Reply With Quote
Old 20 April 2014, 05:32   #14
RIBnet admin team
 
Nos4r2's Avatar
 
Country: UK - England
Town: The wilds of Wiltshire
Boat name: WhiteNoise/Dominator
Make: Ballistic 7.8/SR5.4
Length: 7m +
Engine: Opti 225/Yam 85
MMSI: 235090687/235055163
Join Date: Jul 2005
Posts: 12,645
RIBase
Not yet, though I don't think it's far off. The ground is now 'soft' rather than 'liquid under grass'.

I make about 0.73 miles per litre cruising at 35 knots. I can burn more in my Searider if I get enthusiastic. Worst I've seen at a steady throttle opening was 0.5 mile/litre, though oddly that's not at WOT.
__________________
Need spares,consoles,consumables,hire,training or even a new boat?

Please click HERE and HERE and support our Trade Members.

Join up as a Trade member or Supporter HERE
Nos4r2 is offline   Reply With Quote
Old 20 April 2014, 05:35   #15
Member
 
Country: UK - England
Town: Margate / Ramsgate
Boat name: Ballistic
Make: Ballistic
Length: 7m +
Engine: Yam HPDI 250
Join Date: Feb 2002
Posts: 2,835
Interestingly good for the big block opti.

My big block hpdi on a shorter boat (it's a 3.3li tho, yours is 3.0) is constantly over 1li / nm and at WOT the floscan is off the gauge which reads to 90li/hr so in excess of 2li/nm.
__________________
Daniel is offline   Reply With Quote
Old 20 April 2014, 06:06   #16
RIBnet admin team
 
Nos4r2's Avatar
 
Country: UK - England
Town: The wilds of Wiltshire
Boat name: WhiteNoise/Dominator
Make: Ballistic 7.8/SR5.4
Length: 7m +
Engine: Opti 225/Yam 85
MMSI: 235090687/235055163
Join Date: Jul 2005
Posts: 12,645
RIBase
I should add that at WOT I don't quite believe the flow meter as the Smartcraft is telling me 22 US GPH/hour which works out at 0.52nm/L, but it says 0.6 mile/litre on the EP60R
__________________
Need spares,consoles,consumables,hire,training or even a new boat?

Please click HERE and HERE and support our Trade Members.

Join up as a Trade member or Supporter HERE
Nos4r2 is offline   Reply With Quote
Old 20 April 2014, 11:10   #17
RIBnet supporter
 
Pikey Dave's Avatar
 
Country: UK - England
Town: South Yorks
Boat name: Black Pig
Make: Ribcraft
Length: 5m +
Engine: DF140a
MMSI: 235111389
Join Date: Feb 2008
Posts: 7,590
RIBase
Quote:
Originally Posted by Nos4r2 View Post

I make about 0.73 miles per litre cruising at 35 knots...................... Worst I've seen at a steady throttle opening was 0.5 mile/litre, though oddly that's not at WOT.
That's just what I get, 0.7-0.75nm/l, but at 25kn not 35 That seems to be the sweet spot for the engines, slower actually uses more fuel. I use the fuel info from the engine emm & it's surprisingly accurate.
__________________
Rule#2: Never argue with an idiot. He'll drag you down to his level & then beat you with experience.
Rule#3: Tha' can't educate pork.
Rule#4: See rule#5
Pikey Dave is offline   Reply With Quote
Old 20 April 2014, 12:25   #18
Member
 
Country: UK - England
Town: Gloucestershire
Boat name: Osprey
Make: Osprey Vipermax
Length: 5m +
Engine: E-tec 300 G2
MMSI: TBC
Join Date: Dec 2006
Posts: 4,013
We were at about 1.2 litres per nm at 30knots on the Etec which seemed reasonable for the big 3.4 litre lump...
__________________
---------------------------------------------------
Chris Stevens

Born fiddler
Chris is offline   Reply With Quote
Old 20 April 2014, 13:02   #19
RIBnet supporter
 
Pikey Dave's Avatar
 
Country: UK - England
Town: South Yorks
Boat name: Black Pig
Make: Ribcraft
Length: 5m +
Engine: DF140a
MMSI: 235111389
Join Date: Feb 2008
Posts: 7,590
RIBase
Quote:
Originally Posted by Chris View Post
We were at about 1.2 litres per nm at 30knots on the Etec which seemed reasonable for the big 3.4 litre lump...
Which sounds about right, I'm doing 1.3l/nm with twin 1700cc v4s=3.4l + extra drag & losses.
__________________
Rule#2: Never argue with an idiot. He'll drag you down to his level & then beat you with experience.
Rule#3: Tha' can't educate pork.
Rule#4: See rule#5
Pikey Dave is offline   Reply With Quote
Old 20 April 2014, 14:15   #20
RIBnet admin team
 
Nos4r2's Avatar
 
Country: UK - England
Town: The wilds of Wiltshire
Boat name: WhiteNoise/Dominator
Make: Ballistic 7.8/SR5.4
Length: 7m +
Engine: Opti 225/Yam 85
MMSI: 235090687/235055163
Join Date: Jul 2005
Posts: 12,645
RIBase
Quote:
Originally Posted by Chris View Post
We were at about 1.2 litres per nm at 30knots on the Etec which seemed reasonable for the big 3.4 litre lump...
Just woke up-what's that in NM/L? Guesstimating says it's about the same as I get.
__________________
Need spares,consoles,consumables,hire,training or even a new boat?

Please click HERE and HERE and support our Trade Members.

Join up as a Trade member or Supporter HERE
Nos4r2 is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 22:02.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.