Fuel Flow Meter

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Papasmurf

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Having spent many a happy year chugging around in my Tamar Enterprise 2000 with a 35HP engine where fuel usage was a twice a year fill up I have now got an SD hull, trim tabs and a Yanmar 230HP engine to deal with. I'd like to fit a fuel flow meter to work out optimum settings/speed and avoid overly excessive fuel costs. Any advice on diesel flow meters suitable for the Yanmar engine and fitting tips would be much appreciated.
 
The key to this conundrum flow measurement accuracy and this means something like the Floscan unit, and that is uber expensive.

Be aware that because you have to measure accurately both flow and spill return. With the variable volume being returned to the tank, even very minor sensor inaccuracies can multiply to make the readings so unreliable to mean the metering becomes useless. Accurate measurement of low flow rates is very difficult to achieve with moderately priced sensors. Even fuel temperature and hence viscosity will affect the results to such an effect that at best 10 or even 20% accuracy is as good as you will measure, and the accuracy will vary.

At ~ £1,200 for one meter you might be better simply running a log of distance, speed and fuel added over time.
 
How old is the Yanmar, it may have J1939 BUS in which case the info could already be on the BUS and in such cases a converter can often turn your MFD into a fuel computer cheaper than a dedicated gauge.

It seems that Yanmar RY, SY, GLYS Series motors are N2K so you wouldn't even need a converter if the PGNs are present, and it seems unlikely that they would not be.
 
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Do these work with fairly good accuracy? Superheat6k seemed to suggest the cheaper units were useless? Anyone had experience with one of these units, I'm happy to pay that sort of money if they work. Also are they easy(ish) to fit, I consider myself fairly competent but I'm no marine engineer.
 
Papasmurf said:
Do these work with fairly good accuracy? Superheat6k seemed to suggest the cheaper units were useless? Anyone had experience with one of these units, I'm happy to pay that sort of money if they work. Also are they easy(ish) to fit, I consider myself fairly competent but I'm no marine engineer.
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The problem with all of these kind of fuel flow meters is the device that measures the actual flow of fuel and at low flow rates they are very inaccurate . The flowfcan and the navman I have but not fitted will not work an most marine engines that are used on sail boats and low power power boats.

The one posted does not show very well the type of sender used and moat types are a paddle wheel type that send pulsed to a micro that does the calculations.

I also looked at making a unit like Nigel and came to the same conclusion that it was not worth it with the current types of senders due to its inherent inaccuracies .

I do not believe the unit posted can give good accurate results from a 20 HP engine but it may with higher power engines but how are you going to tell.
 
Although this is an old thread, I understand that Flowtrecs now have a diesel version available. Did you also know that Floscan have ceased production as the owner retired and decided to close the business!
Scintex in Australia are another contender but I'm looking at the Flowtrecs at the moment as their prices are very good. Whether the products are is another story although they have in business for some years with their petrol versions.
 
I'm not sure whether this is applicable as not sure whether your engine has an interface and if so what kind but I wanted to see my fuel flow as well and after lots of research I got this engine gateway for my KAD 44 which includes fuel flow readings.

http://www.yachtd.com/

I connected this to my raymarine mfd and it even provides "estimated" fuel remaining readings however I've been using mine for around a year and have found it accurate within a litre or so which I think is pretty impressive.

Regards
 
The problem with fuel flow meters on small diesel engines as in sail boats is the most covenesion fuel flow measuring sensors are not sensitive enough to measure the small flow accuracy enough.

I did start to look at venturi flow measuring sensors using the new solid state differential pressure transducers but the size of the venturi was very small and I could not fine one off the shelf small enough.
 
I am a sailboat owner and am very interested in this thread. I have a 44’ sailboat with a 54 hp engine, consuming anywhere between 3 - 5 litres per hour or so depending on revs. So far this year, with little wind, I have been motoring a lot, used over 600 litres. :(

The fitted fuel tank gauge is useless, and so I have been making regular log records of engine hours and revs (yanmar engine hour meter is also intermittent). Fuel tank is large plastic tank under aft cabin berth, black so cannot see fuel level.

I could look at a new fuel gauge but am reluctant to cut holes in the fuel tank with the worry of making the seal at the gauge fitting work properly. A fuel flow gauge would potentially be better, so am l looking seriously into this. Some of the kit made by flowtrecs looks ideal (if a little expensive) - has anyone actually fitted one of these and can report back?
 
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