Bejasus
New member
anyone got fuel curves for a Ford Lehman(Dorset) 2712E 80hp.
Fuel Consumption
- Thread starter Bejasus
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A
Anonymous
Guest
The specific fuel consumption is much the same for all diesel engines provided they are adjusted correctly and not smoking. I have converted the usual figure quoted (gm per hp-hr) into something more useful...... For each horsepower you are 'using' you will burn 0.15 litres per hour.
For example, if you have a 50hp engine and you are running at half power (NOTE, power, not revs) then you are using 25hp and your fuel consumption will be 3.75 litres per hour. You will not better that figure and if you are running much worse, you will see a cloud of smoke behind you.
What you now need is the curve of RPM vs shaft hp for your engine/gearbox/prop assembly,which should be much easier to find than the fuel consumption curve per se.
For example, if you have a 50hp engine and you are running at half power (NOTE, power, not revs) then you are using 25hp and your fuel consumption will be 3.75 litres per hour. You will not better that figure and if you are running much worse, you will see a cloud of smoke behind you.
What you now need is the curve of RPM vs shaft hp for your engine/gearbox/prop assembly,which should be much easier to find than the fuel consumption curve per se.
reeac
Well-known member
[ QUOTE ]
The specific fuel consumption is much the same for all diesel engines provided they are adjusted correctly and not smoking. I have converted the usual figure quoted (gm per hp-hr) into something more useful...... For each horsepower you are 'using' you will burn 0.15 litres per hour.
For example, if you have a 50hp engine and you are running at half power (NOTE, power, not revs) then you are using 25hp and your fuel consumption will be 3.75 litres per hour. You will not better that figure and if you are running much worse, you will see a cloud of smoke behind you.
What you now need is the curve of RPM vs shaft hp for your engine/gearbox/prop assembly,which should be much easier to find than the fuel consumption curve per se.
[/ QUOTE ]
Not sure about your numbers. Taking the traditional 20 bhp.hrs per gallon of diesel I make that 0.227 litres per bhp hour.
The specific fuel consumption is much the same for all diesel engines provided they are adjusted correctly and not smoking. I have converted the usual figure quoted (gm per hp-hr) into something more useful...... For each horsepower you are 'using' you will burn 0.15 litres per hour.
For example, if you have a 50hp engine and you are running at half power (NOTE, power, not revs) then you are using 25hp and your fuel consumption will be 3.75 litres per hour. You will not better that figure and if you are running much worse, you will see a cloud of smoke behind you.
What you now need is the curve of RPM vs shaft hp for your engine/gearbox/prop assembly,which should be much easier to find than the fuel consumption curve per se.
[/ QUOTE ]
Not sure about your numbers. Taking the traditional 20 bhp.hrs per gallon of diesel I make that 0.227 litres per bhp hour.
A
Anonymous
Guest
[ QUOTE ]
Not sure about your numbers. Taking the traditional 20 bhp.hrs per gallon of diesel I make that 0.227 litres per bhp hour.
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The figure in my Yanmar manual (4LH series) gives 170 gr/hp-h and I checked it a couple of years ago to agree with other engines. I can't remember where I put my calculations but you have to convert mass to volume, of course.
Is your figure UK or US gallons?
Not sure about your numbers. Taking the traditional 20 bhp.hrs per gallon of diesel I make that 0.227 litres per bhp hour.
[/ QUOTE ]
The figure in my Yanmar manual (4LH series) gives 170 gr/hp-h and I checked it a couple of years ago to agree with other engines. I can't remember where I put my calculations but you have to convert mass to volume, of course.
Is your figure UK or US gallons?
npf1
Active member
FYI - I've just applied both the 0.15 and the 0.227 to my set-up, using Perkin's curves to guestimate the actual power at different RPM. The 0.15 number was pretty much bang on what I have used per trip over the past few years (approx 800 hours).
PCUK
Well-known member
These are the figures I have always worked with using UK gallons:-
20hp naturally aspirated diesel
23 hp turbo diesel
20hp naturally aspirated diesel
23 hp turbo diesel
A
Anonymous
Guest
Where did the figures come from, or how did you derive them?
reeac
Well-known member
[ QUOTE ]
Where did the figures come from, or how did you derive them?
[/ QUOTE ]
The figures of 20 and 23 bhp.hours per gallon are frequently quoted as broad brush values. Specific engine manufacturers often give fuel consumption vs. speed [rpm] in their brochures - in grammes per bhp.hour if I recall correctly. Nanni and Vetus brochures give data at mid-range speeds that agree with the above broad brush values.
Where did the figures come from, or how did you derive them?
[/ QUOTE ]
The figures of 20 and 23 bhp.hours per gallon are frequently quoted as broad brush values. Specific engine manufacturers often give fuel consumption vs. speed [rpm] in their brochures - in grammes per bhp.hour if I recall correctly. Nanni and Vetus brochures give data at mid-range speeds that agree with the above broad brush values.
A
Anonymous
Guest
[ QUOTE ]
The figures of 20 and 23 bhp.hours per gallon are frequently quoted as broad brush values. Specific engine manufacturers often give fuel consumption vs. speed [rpm] in their brochures - in grammes per bhp.hour if I recall correctly. Nanni and Vetus brochures give data at mid-range speeds that agree with the above broad brush values.
[/ QUOTE ]That's a massive range - 10%. I wouldn't feel comfortable relying on those numbers without a bit more checking and confirmation. My figure comes straight from the Yanmar curve in the workshop manual.
The figures of 20 and 23 bhp.hours per gallon are frequently quoted as broad brush values. Specific engine manufacturers often give fuel consumption vs. speed [rpm] in their brochures - in grammes per bhp.hour if I recall correctly. Nanni and Vetus brochures give data at mid-range speeds that agree with the above broad brush values.
[/ QUOTE ]That's a massive range - 10%. I wouldn't feel comfortable relying on those numbers without a bit more checking and confirmation. My figure comes straight from the Yanmar curve in the workshop manual.
reeac
Well-known member
[ QUOTE ]
[ QUOTE ]
The figures of 20 and 23 bhp.hours per gallon are frequently quoted as broad brush values. Specific engine manufacturers often give fuel consumption vs. speed [rpm] in their brochures - in grammes per bhp.hour if I recall correctly. Nanni and Vetus brochures give data at mid-range speeds that agree with the above broad brush values.
[/ QUOTE ]That's a massive range - 10%. I wouldn't feel comfortable relying on those numbers without a bit more checking and confirmation. My figure comes straight from the Yanmar curve in the workshop manual.
[/ QUOTE ]
The 20 and 23 do not represent a range - the 20 is for naturally aspirated and the 23 is for turbocharged diesel engines.
[ QUOTE ]
The figures of 20 and 23 bhp.hours per gallon are frequently quoted as broad brush values. Specific engine manufacturers often give fuel consumption vs. speed [rpm] in their brochures - in grammes per bhp.hour if I recall correctly. Nanni and Vetus brochures give data at mid-range speeds that agree with the above broad brush values.
[/ QUOTE ]That's a massive range - 10%. I wouldn't feel comfortable relying on those numbers without a bit more checking and confirmation. My figure comes straight from the Yanmar curve in the workshop manual.
[/ QUOTE ]
The 20 and 23 do not represent a range - the 20 is for naturally aspirated and the 23 is for turbocharged diesel engines.
A
Anonymous
Guest
[ QUOTE ]
[The 20 and 23 do not represent a range - the 20 is for naturally aspirated and the 23 is for turbocharged diesel engines.
[/ QUOTE ]
OK but where do these figures come from and/or how have you been able to verify them as accurate?
Edit:- Sorry, you had said earlier that they agreed with Nanni etc. data. Well, I am puzzled that there should be such a large difference in the inherent economy of similar diesel engines. I cannot explain it but for the time being I shall work with my figures as I have a hard copy of where they come from. "Broad brush" as a description of a piece of data does not fill me with any confidence.
[The 20 and 23 do not represent a range - the 20 is for naturally aspirated and the 23 is for turbocharged diesel engines.
[/ QUOTE ]
OK but where do these figures come from and/or how have you been able to verify them as accurate?
Edit:- Sorry, you had said earlier that they agreed with Nanni etc. data. Well, I am puzzled that there should be such a large difference in the inherent economy of similar diesel engines. I cannot explain it but for the time being I shall work with my figures as I have a hard copy of where they come from. "Broad brush" as a description of a piece of data does not fill me with any confidence.
reeac
Well-known member
[ QUOTE ]
[ QUOTE ]
[The 20 and 23 do not represent a range - the 20 is for naturally aspirated and the 23 is for turbocharged diesel engines.
[/ QUOTE ]
OK but where do these figures come from and/or how have you been able to verify them as accurate?
[/ QUOTE ]
As I said earlier, I've seen graphs for Nanni and Vetus engines. I have no way of checking their accuracy and I can't see how any boat owner could do so as he'd have to know how many bhp it took to drive his boat along at any given speed. Alternatively he'd need to know the particular form of the "prop. law" that applied to his set up eg. is it the 2.8 exponent or cube of rpm etc.
[ QUOTE ]
[The 20 and 23 do not represent a range - the 20 is for naturally aspirated and the 23 is for turbocharged diesel engines.
[/ QUOTE ]
OK but where do these figures come from and/or how have you been able to verify them as accurate?
[/ QUOTE ]
As I said earlier, I've seen graphs for Nanni and Vetus engines. I have no way of checking their accuracy and I can't see how any boat owner could do so as he'd have to know how many bhp it took to drive his boat along at any given speed. Alternatively he'd need to know the particular form of the "prop. law" that applied to his set up eg. is it the 2.8 exponent or cube of rpm etc.
Chris_Robb
Well-known member
Very interesting - my experiance is
My last boat - Long Keel Victory 40 - engine Perkins 4236 (72bhp). Motoring in flat to F3 - 4 - about 4.5 ltrs per hour(approx 7knts). Motoring long distance into f6 - 7s, (7 knots) consumotion appeared to double - same revs - but obviously using twice the power.
New boat (Westerly Ocean Lord) Volvo 2003Turbo (43bhp) uses almost exactly the same in light to mod conditions - not checked heavier conditions, as 7 knots would not be acheivable. A bit surpised at this, as I would have expected her to be an easier driven hull and use about 3 ltr per hour. - or is the Turbo the difference?
Her indoors can't understand why we now have to sail to windward, as its now faster than motoring! I suppose I am not a gentleman any more!
My last boat - Long Keel Victory 40 - engine Perkins 4236 (72bhp). Motoring in flat to F3 - 4 - about 4.5 ltrs per hour(approx 7knts). Motoring long distance into f6 - 7s, (7 knots) consumotion appeared to double - same revs - but obviously using twice the power.
New boat (Westerly Ocean Lord) Volvo 2003Turbo (43bhp) uses almost exactly the same in light to mod conditions - not checked heavier conditions, as 7 knots would not be acheivable. A bit surpised at this, as I would have expected her to be an easier driven hull and use about 3 ltr per hour. - or is the Turbo the difference?
Her indoors can't understand why we now have to sail to windward, as its now faster than motoring! I suppose I am not a gentleman any more!
Bejasus
New member
[ QUOTE ]
anyone got fuel curves for a Ford Lehman(Dorset) 2712E 80hp.
[/ QUOTE ]
Ok, ok......................let's approach this from a different angle.
I currently own a cruising saiboat boat with the above engine. I do not trust my current fuel gauge set up and I am planning to sail across the Atlantic, around next May. Given that my tankage is 180 usg, how much additional fuel should I look at setting off with. Planned route is not to stop in Bermuda unless we really have to, but a stop in the Azores is definitely planned.
Incidentally, I am planning to fit a Floscan fuel monitoring system and mechanical gauges to the tanks.
anyone got fuel curves for a Ford Lehman(Dorset) 2712E 80hp.
[/ QUOTE ]
Ok, ok......................let's approach this from a different angle.
I currently own a cruising saiboat boat with the above engine. I do not trust my current fuel gauge set up and I am planning to sail across the Atlantic, around next May. Given that my tankage is 180 usg, how much additional fuel should I look at setting off with. Planned route is not to stop in Bermuda unless we really have to, but a stop in the Azores is definitely planned.
Incidentally, I am planning to fit a Floscan fuel monitoring system and mechanical gauges to the tanks.
A
Anonymous
Guest
The theoretical fuel consumption is only one (fairly small) part of the story when it comes to passage planning. There is no practical way you can set a diesel to a fixed power output unless there is no sea as the governor tries to hold shaft speed constant regardless of load (power).
As for how much fuel you will need, surely this is a matter of luck and personal choice - you could sail the whole way, with only enough fuel for entering harbours and power generation. On the other hand, you could motor whenever your speed drops below 6 kts.
As for how much fuel you will need, surely this is a matter of luck and personal choice - you could sail the whole way, with only enough fuel for entering harbours and power generation. On the other hand, you could motor whenever your speed drops below 6 kts.
Bejasus
New member
Yawn.......................zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
Mudplugger
New member
Might be worth giving Lancing Marine a call, speak to Mark or Mike Bellamy, both exceeding knowledgeable in matters relating to Ford!, Have similar size 2.4. FSD and consumption figures are projected @ 10 bhp per litre, so projected @ full revs about 8.5l per hour, 18Ton Ferro Smack has similar engine, and consumption over the last 6 years appears to average out @ 5l per hour... Max revs in region of 4200, but rarely used above 3000. Swinging a 21" 3 blade prop. HTH
A
Anonymous
Guest
[ QUOTE ]
Yawn.......................zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
[/ QUOTE ]
Shame the reply was too technical for you but it's your own fault - you did ask for the curves.
Yawn.......................zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
[/ QUOTE ]
Shame the reply was too technical for you but it's your own fault - you did ask for the curves.
Bejasus
New member
[ QUOTE ]
Shame the reply was too technical for you but it's your own fault - you did ask for the curves.
[/ QUOTE ]
somehow I don't think the reply was too technical, since I am a fully trained mechanic in a past life. Your right, I did ask for the curves, but that was all I asked for. I am fully capable of working out all the other stuff for myself. So a simple yes or no would have done instead of all the other 'technical' stuff I didn't ask for. I simply have all my info on my boat which happens to be in Savannah in the US, whilst I am currently at work in Denmark, and unable to access it at this time.
Shame the reply was too technical for you but it's your own fault - you did ask for the curves.
[/ QUOTE ]
somehow I don't think the reply was too technical, since I am a fully trained mechanic in a past life. Your right, I did ask for the curves, but that was all I asked for. I am fully capable of working out all the other stuff for myself. So a simple yes or no would have done instead of all the other 'technical' stuff I didn't ask for. I simply have all my info on my boat which happens to be in Savannah in the US, whilst I am currently at work in Denmark, and unable to access it at this time.
Bejasus
New member
Thanks Mudplugger. I have spoken with both Mark & Mike in the past, when I re-engined another boat. It may well be that they have a copy of the curves and can email it to me.
