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29-08-2009, 15:53
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#1
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Registered User
Join Date: Mar 2009
Location: Pittwater, Sydney, Australia
Boat: Swanson 38" 'SWANSONG 1'
Posts: 46
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Diesel Consumption - Volvo D2 - 55hp
I am having a new 220 litres tank installed as well as a new Volvo D2 55 on my 38' sailboat.
Would someone please clarify to me what's the approximate fuel consumption of a Volvo D2-55 shaft propeller drive no more than 2,200 rpm, max speed 6 knots?
The way I read the fuel consumption curve on the Volvo pamphlet at
http://www.marinedieseldirect.com/re...d2_55_55hp.pdf
indicates over 5 litres per hour.
The mechanic insists it is more like 2 litres per hour
Thank you!
Paolo
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29-08-2009, 16:16
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#2
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Registered User
Join Date: May 2008
Location: Sandspit, New Zealand
Boat: Farr 46
Posts: 134
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here are some consumption figures for an HR40/56 hp yanmar. You can expect something similar. It all comes down to waterline lenght, disp and the load on the engine, in particular correct prop sizing. You will note at full power consumption will be around 10 lph
go to
http://www.hallberg-rassy.com/yachts/hallberg-rassy40,
scroll down to documents and select fuel consumption
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29-08-2009, 17:16
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#3
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Registered User
Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 20,420
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200 grams per horse power, probably less for D2 if run at optimum ("economy") rpms
go into the hp/rpm table with the rpms, read the power generated, multiply
they also give the exact data in the leaflet (available online)
b.
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29-08-2009, 18:16
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#4
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Registered User
Join Date: Mar 2009
Location: Pittwater, Sydney, Australia
Boat: Swanson 38" 'SWANSONG 1'
Posts: 46
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Thank you, barnakiel.
This is where I get confused. I have the Volvo Penta D2-55 pamphlet with Fuel Consumption offered in two graphs, At Full Load and At Calculated Propeller Load exp.3 (?).
At 2200 rpm the lower graph shows 5 liters/h. The upper graph shows 9 liters/h. The notes offer no clues.
Regards
Paolo
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29-08-2009, 19:19
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#5
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Registered User
Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 20,420
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At full load and 2200 rpm = 8 liters per hour. But imagine now that you unload the engine (put the gear into neutral) and then rev it up to 2200 rpm. Will it burn more / less? Imagine you are running at 120 steps per minute and then you do the same but fully loaded up say with a heavy rucksack. When will you burn more energy (use more fuel)?
Hence the second curve which allows for this phenomenon. From this curve you learn 5 liters is what you might expect, say in flat water, while under more load the consumption may go all the way until 8 liters. Even more load and the engine will get 'overloaded' and start to smoke!
b.
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29-08-2009, 20:29
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#6
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Registered User
Join Date: Mar 2009
Location: Pittwater, Sydney, Australia
Boat: Swanson 38" 'SWANSONG 1'
Posts: 46
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Fuel consumption
Quote:
Originally Posted by barnakiel
At full load and 2200 rpm = 8 liters per hour. But imagine now that you unload the engine (put the gear into neutral) and then rev it up to 2200 rpm. Will it burn more / less? Imagine you are running at 120 steps per minute and then you do the same but fully loaded up say with a heavy rucksack. When will you burn more energy (use more fuel)?
Hence the second curve which allows for this phenomenon. From this curve you learn 5 liters is what you might expect, say in flat water, while under more load the consumption may go all the way until 8 liters. Even more load and the engine will get 'overloaded' and start to smoke!
b.
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This is quite clear.
Because the new tank is 220 litres, under average load I can expect only ~36 hrs autonomy.
Many thanks again.
Paolo
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30-08-2009, 10:05
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#7
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Registered User
Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 20,420
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To some extent it depends on the hull of your 38 footer.
A modern 41 will displace some 7-8 metric tonnes, an older design easily twice this amount. You need roughly 2 hp / t to drive the hull at econo speed (where consumption per mile is lowest) this would mean some 15-20 hp times 200 grams say 3.5 liters per hour and probably at around 5.5-6.5 knots. This makes possibly 60+ hours on a tank = 350-400 Nautical miles on one tank.
Now the heavier boat will burn twice the amount and end up with half the range. Since you have a 53hp engine in a 38 footer I am lead to imagine that your boat is mid- or heavy displacement.
To extend you range you can be looking for the rpm / speed where consumption per mile is lowest - sometimes it is actually rather slow and many skippers decide to shorten the range but go at slightly higher speed / spend less time on the passage. If this is the case then your engine is matched well and it will be properly loaded which is always good for the longevity of the engine (diesels hate to be run under light loads).
b.
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30-08-2009, 16:01
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#8
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Registered User
Join Date: Mar 2009
Location: Pittwater, Sydney, Australia
Boat: Swanson 38" 'SWANSONG 1'
Posts: 46
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Fuel consumption
Well, you have a tremendous knowledge, and in this case quite reassuring.
Should we go for longer cruises across areas without possibility of refuelling, there will always be the portable, soft tank option.
Will let you know, in any case, as soon as I get my boat back, what's the actual consumption in diverse conditions of use.
Thank you again.
Paolo
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30-08-2009, 17:24
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#9
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Registered User
Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 20,420
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I only have the knowledge that I read from the leaflets and some general books (Calder is good on engines and things electrical).
Happy sailing!
b.
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02-10-2015, 18:04
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#10
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Registered User
Join Date: Apr 2010
Location: Tasmania
Boat: Swanson 36 in Australia Bavaria 42 in Med
Posts: 340
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Re: Diesel Consumption - Volvo D2 - 55hp
My Bavaria 42 is in Greece. It too has a Volvo D2 55.
In the Ionian Sea area there is very little wind so each summer we do about 150 hours of motoring. Distances to travel are short so we snoozle along at about 1800 RPM and 5 knots. We are using little more than one LPH. Very surprising. Some of those hours were for charging batteries.
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19-06-2017, 10:51
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#11
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Registered User
Join Date: Feb 2007
Location: Gig Harbor, WA
Boat: Tayana Vancouver 42ac
Posts: 1,196
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Re: Diesel Consumption - Volvo D2 - 55hp
I have a Volvo Penta D2-55B in my Tayana Vancouver 42. I have owned the boat since 2007 and now have just over 1,000 hours on the engine. I keep very detailed records of my fuel consumption and have averaged 1.2 US gals. per hour at cruse speed, 2300RPM.
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20-06-2017, 22:46
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#12
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Registered User
Join Date: Jun 2017
Location: BRISBANE
Boat: PERRY 43 PASSAGEMAKER
Posts: 76
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Re: Diesel Consumption - Volvo D2 - 55hp
All displacement boats have a maximum hull speed which is 1.34 times the square root of the waterline. This also can be be determined by looking at the wave action as the boat moves through the water, when the distance between the bow wave and stern wave equal the length of the boat, that is considered the boats hull speed. Pushing the boat pass that speed will consume a disportionate amount of fuel.
Cheers
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20-06-2017, 23:39
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#13
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Registered User
Join Date: Jul 2005
Location: Bellingham
Boat: Outbound 44
Posts: 9,319
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Re: Diesel Consumption - Volvo D2 - 55hp
Quote:
Originally Posted by Marinheiro
here are some consumption figures for an HR40/56 hp yanmar. You can expect something similar. It all comes down to waterline lenght, disp and the load on the engine, in particular correct prop sizing. You will note at full power consumption will be around 10 lph
go to
Page not found,
scroll down to documents and select fuel consumption
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Direct link to PDF
http://www.hallberg-rassy.com/filead...rFlexofold.pdf
__________________
Paul
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