Flowmeters

AKDoug · Apr 10, 2013

I have always had a gas engine, it drank lots of fuel so the flowmeter worked well and had a totalizer for gallons consumed. Kind of a double safety for not running out of fuel. My new boat has a Yanmar 4JH3E and the fuel consumption should be in the liters per hour range. The question would be Is There a Flowmeter that will read flows that low? What does everyone with a small engine do to compute fuel consumption? Do you just measure your tankage and shoot for an average? I understand the diesel engine also bypasses a quantity of fuel back into the tank as part of the process. Wanting to know before I get there...

Codger2 · Apr 10, 2013

AKDoug said:
My new boat has a Yanmar 4JH3E and the fuel consumption should be in the liters per hour range. The question would be Is There a Flowmeter that will read flows that low?

Floscan Instrument Co. Inc.

AKDoug · Apr 10, 2013

I didn't see one for flows that low, I have my second FloScan in my Bayliner now. The issue with the return line remains. Do you have one installed in a diesel installation?

Codger2 · Apr 10, 2013

AKDoug said:
Do you have one installed in a diesel installation?

Yes and it works great! Did you check all the models? How many litres /hr do you want to monitor?

AKDoug · Apr 10, 2013

Sweet! Thank you very much, my Internet search didn't turn up this one. I am guessing 4-6 liters per hour or the equivalent. I read a couple of articles while searching and the return line question was stated. Got to love Google, sometimes...

Tom.B · Apr 10, 2013

I would consider holding off. It's a big expense for a diesel version, and will it be accurate enough to do you significant good? I don't know how you are cruising or what your engine burns, but on Skinny Dippin', we are at or near cruising speed or stopped. Would saving a few tenth of a gallon be legible on a meter like that? Would a few tenth of a gallon make a difference? In the LONG run, sure, but I was in the flowmeter camp when we first started, but now, I know we get 2.0 gph and have marks on my sight tubes.

YMMV :rofl:

AKDoug · Apr 10, 2013

New boat, many things to upgrade. Of course the first inclination is to try to replicate what you did on your last boat, but I was rather just seeking information for the future. My favorite function on the one on the Bayliner is the totalizer. It is so reassuring to see the gallons going in closely approximate what is read as going out. When you always know what you started with, it is nice to read down to the point where it is time to be looking for fuel.

markpierce · Apr 10, 2013

There are choices of scales. Mine is up to 10 GPH but only half is needed. And then there is Walt's which needs several times the range...

Mine: top right-hand meter, above the rudder indicator:

Codger2 · Apr 10, 2013

markpierce said:
There are choices of scales. Mine is up to 10 GPH but only half is needed.

Damn... you did it again! Quit posting that panel! I love it!

markpierce · Apr 10, 2013

SeaHorse II said:
Damn... you did it again! Quit posting that panel! I love it!

Walt, it helps to have a cooperative boat builder. ... It started with this mock-up from the project manager (presumably radar and depth finder display would be in upper right):

Then to this based on my insistence:

Tank-scale was moved to a bulkhead, and displays/controls relevant to a lookout were moved toward the boat's center while those primarily of the helmsman's interest were moved to the opposite side.

Tom.B · Apr 10, 2013

markpierce said:
There are choices of scales. Mine is up to 10 GPH but only half is needed. And then there is Walt's which needs several times the range...

Mine: top right-hand meter, above the rudder indicator:

I totally understand that (and that is a cool dash BTW), but would it be accurate, or even needed, at 2 gph or less?

Al · Apr 10, 2013

Mark, As always, your photos are impressive and timely. Now, for total envy purposes, go twin screw and really impress us with THAT dash, this one is a beaut.
Thanks for all the photos you submit.
A Johnson-Ketchikan (Bridge to Nowhere) Alaska

CPseudonym · Apr 10, 2013

Tom.B said:
I totally understand that (and that is a cool dash BTW), but would it be accurate, or even needed, at 2 gph or less?

My take away on flow meters ROI has been ten GPH or more, twenty IMO is closer to reality for a true cost savings. Justifying the expense on much less GPH based on fuel savings is an exercise in futility. JMO

markpierce · Apr 11, 2013

CPseudonym said:
My take away on flow meters ROI has been ten GPH or more, twenty IMO is closer to reality for a true cost savings. Justifying the expense on much less GPH based on fuel savings is an exercise in futility. JMO

That point of view is relevant for any GPH as it is all relative. If you want to be economical, run your boat slow at 2 GPH. If you know the RPM required for that rate of consumption, you might not need a flow meter. And if you aren't concerned about your fuel consumption, you don't need a meter either. But I like to know what's happening "now" as well as what amount of fuel has been cumatively consumed.

MurrayM · Apr 11, 2013

The suggested retail price of a Floscan for a Yanmar 4JH2-UTE 100hp engine is $1,010.00

Egad!

Any other alternatives for those of a more frugal nature?

Codger2 · Apr 11, 2013

Tom.B said:
I totally understand that (and that is a cool dash BTW), but would it be accurate, or even needed, at 2 gph or less?

Tom: I understand your take and if all the Floscan tells you is what your burning (gph) and what you've used (totalizer) you have a point. I've tried to explain the other advantages of the FloScan, in past posts, but apparently haven't done a very good job at it. It also tells you if you have a fuel leak by showing a marked increase in the gph. A dirty bottom or a fouled prop also can be seen with a slight increase of fuel usage at a known rpm. It's main advantage, however, is an accurate accounting of fuel burned, fuel remaining & distance remaining at a particular throttle setting. (gps) Dick Rutan had FloScans onboard Challenger on his epic round the world, non stop flight. They actually saved his bacon when leaving Africa and heading for South America.

Newer electronic engines also show your fuel info but those systems are based on a calculation of what the engine should be burning at various throttle settings. FloScan actually measures the actual fuel being used. It's not a calculation.

markpierce · Apr 11, 2013

MurrayM said:
The suggested retail price of a Floscan for a Yanmar 4JH2-UTE 100hp engine is $1,010.00

Egad!

"Small potatoes" when one considers most boats in the TF internet neighborhood have two propulsion engines and duplicate helms.

CPseudonym · Apr 11, 2013

I completely see your point Mark but as the devices big selling point, to me anyway, is the ability to pay for themselves in fuel saved. I would require quite a large number of hours to see it pay for itself at 2 GPH.

I do not deny that they are nice to have or that they can pay for themselves in fuel offsets. I just see fuel as a small expense in the grand scheme of things. If we cruised distances like Larry or had hungry large engines like George's Hatteras we probably wouldn't be without them.

Edit: Just saw your post Walt and great points I've never considered.

markpierce · Apr 11, 2013

Craig, I never considered a Flowscan as a cost-savings device, anymore than having flag halyards. By avoiding the costs of a second engine, second helm position, and teak-covered decks, there was money for other good stuff, like an outrageously-expensive yet loud-and-beautifuuly-sounding air horn!

FF · Apr 11, 2013

"It's a big expense for a diesel version, and will it be accurate enough to do you significant good? "

The first time you are cruising and KNOW you will take 60 gal and the fuel dock sez 75gal pumped for fill up will easily pay for the gauge and its installation.

CaptTom · Apr 11, 2013

Knowing how much fuel I burned, how much I have left, and how far I can go on that fuel at all times is the real value of a FloScan. I would never try to justify it on fuel savings alone. Still, it's not on the short list of "must haves" when I consider the price for two engines and two helm stations! I think there's a real opportunity for another company to compete on price here.

westwinds · Apr 11, 2013

maretron.com/products/ffm100.php
$395 Fuel Flow Monitor. When you divide speed over ground determined from GPS by gallons per hour, you get miles per gallon. If you have wind and current influences, try different power settings to find best miles per gallon. Note how accurate this meter is!

Brooksie · Apr 11, 2013

westwinds said:
maretron.com/products/ffm100.php
$395 Fuel Flow Monitor. When you divide speed over ground determined from GPS by gallons per hour, you get miles per gallon. If you have wind and current influences, try different power settings to find best miles per gallon. Note how accurate this meter is!

Nice looking quality stuff indeed. These oval gear meters are one of the most accurate methods of liquid measurement from my experience with lubricant meters. However this is a VERY expensive system the $395. price is for just the "brain" box. You must add two meters, display, filters, cables, and so on.

Conrad · Apr 11, 2013

Mine doesn't do well below about two gallons a hour, but to answer parrot of your question, there are sensors that measure the total flow and the return flow, so the readout is the calculated flow that actually goes to the engine.

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