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#454740 - 03/10/09 02:31 PM To Sensor or Not, That is the Question - Fuel Flow Meter  
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Titanium Offline
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I'm a little confused on fuel flow meters. Why would someone get a Floscan type of meter, which requires a sensor, rather than a Mercury or Faria SmartCraft gauge that doesn't appear to need a sensor? Plus the Mercury and Faria gauges do a lot more than just show fuel flow.

Are the dedicated fuel flow meters such as Floscan more accurate than the SmartCraft gauges? I assume the SmartCraft gauges get only an estimated fuel flow from the engine ECM.

I'm trying to understand the pro's and con's of the different technologies a little better. Thanks for any help.


In theory, there is no difference between theory and practice. In practice, there is.

07 Cobalt 240 w/ Merc 496 Mag MPI V8 Bravo 3
05 Dodge Ram 1500 QuadCab 5.7L V8 Hemi
07 SeaDoo Wake 215, 1996 SeaDoo GTX, 05 HD Dyna SuperGlide
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#454741 - 03/10/09 03:00 PM Re: To Sensor or Not, That is the Question - Fuel Flow Meter [Re: Titanium]  
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Al Offline
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One issue, at least the one I am struggling with, is that older engines do not provide fuel flow information from the engine. I think only engines made since around 2006 or later provide that kind of information, which includes Mercury (Smartcraft), Volvo (NMEA2000), Yanmar (NMEA2000), Crusader (NMEA2000), and several others that do NMEA2000. Some engines will do J-1939, which a interface can be had by Maretron to convert to NMEA2000, but those engines are generally late model versions as well.

Another issue is if you have a Mercury engine, it will not do NMEA2000, which is the current industry standard. Smartcraft is properitary and will not interface with NMEA2000.

While this may not be an issue for engine monitoring, a typical NMEA2000 network processes much more information than engine parameters, and its common to see Multi-Function displays used. For instance, should you interface NMEA2000 fuel flow data to a MFD with GPS input, you can get not only GPH, but also MPG, Miles to Empty, and so on.

While its true that you can do this with a Mercury engine and a NorthStar MFDs, they are the only ones that I am aware of that can provide a Smartcraft interface (because they are owned by Brunswick).

This leaves out RayMarine, Garmin, Lowrance, and all of the other MFD/GPS/Radar manufacturers.

As far as accuracy, I do not know which is better, but the typical aftermarket fuel flow setup is done with paddlewheels, and can be accurate to within 1%. I don't know if the engine-mounted versions use paddlewheels, vaccum, or what, or what their typical accuracy is.


President and CEO - Napmoor and Doolittle.


2004 Mercury 270 Dinghy.
2016 Grand Design Reflection 29RS 5th Wheel
2016 GMC Sierra 2500HD SLT 6.6L Diesel

previous boats:
1995 Carver 325
1999 Four Winns 268
1999 Four Winns 225
1996 Rinker 180
#454743 - 03/10/09 03:08 PM Re: To Sensor or Not, That is the Question - Fuel Flow Meter [Re: Al]  
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Titanium,
I don't know about the other brands you mentioned, but I have a Floscan system for my engines. Yes, it requires the flow meter (sensor) attached to the engines, but that's a piece of cake to install.

After using the Floscans for a few years I find it rely on it to let me know when I'm cruising at the most efficient speed/rpm.

As the load on my boat changes due to more/fewer passengers, fuel and water loads, etc., I have to change my cruise rpm's. As I change throttle positions I can monitor the flow of fuel and find a sweet spot to cruise at.

The upside of a fuel monitoring system is that it lets you know how much fuel you're burning. The downside is that it lets you know how much fuel you're burning. laugh laugh


"Beachcomber" 1995 Sea Ray 550 Sedan Bridge


Anchor's down......Bottoms Up!
#454746 - 03/10/09 03:31 PM Re: To Sensor or Not, That is the Question - Fuel Flow Meter [Re: GoFirstClass]  
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Al Offline
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After reading GFC's post, I should have stated that not all aftermarket fuel flow systems are NMEA2000 capable. Many are stand-alone instruments.

With those, you get a GPH reading and you must supply your own speed information, such as from a GPS, and then do the math to get MPG.

So it should be stated that the aftermarket ones vary from stand alone to those fully integraged into a nav system. It just depends on how much money you want to spend.


President and CEO - Napmoor and Doolittle.


2004 Mercury 270 Dinghy.
2016 Grand Design Reflection 29RS 5th Wheel
2016 GMC Sierra 2500HD SLT 6.6L Diesel

previous boats:
1995 Carver 325
1999 Four Winns 268
1999 Four Winns 225
1996 Rinker 180
#454785 - 03/11/09 12:13 AM Re: To Sensor or Not, That is the Question - Fuel Flow Meter [Re: Al]  
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Titanium

A few years back we installed a Smartcraft SC1000 System Tachometer/Speedometer in our 2002 Cobalt with the Mercruiser 5.0 MPI engine. The Smartcraft system harness has a NMEA 0183 v1.5 or v2.0 connection for an external GPS; facilitating the acquisition of speed data and system time. The Smartcraft system may operate on a proprietary network, I don't know, but it does at least have an older NMEA standard interface it can translate.

I have experienced fuel flow accuracy to be within a gallon, when filling our 50 gallon tank. (For the record, I would think a quality flow meter would be more accurate.)

http://www.mercurymarine.com/otherproducts/smartcraft/smartcraftataglance/components/gauges.php

Hope this helps.


'02 Cobalt 206 - Classic Navy - 5.0 MPI Bravo III

“The heart of the wise inclines to the right, but the heart of the fool to the left.”
Ecclesiastes 10:2 (NIV)
#454787 - 03/11/09 01:24 AM Re: To Sensor or Not, That is the Question - Fuel Flow Meter [Re: Al]  
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Al and GFC,

Thanks for the replies.

Al: I can see how the age of your engine (i.e prior to the time of Mercury adding in SmartCraft capability to their gas engines, although I assume you have diesel power) would naturally lead you down the NMEA2000 pathway. Especially since you have a much larger boat with many more systems that you want to tie into the NMEA2000 network. I would have done the same as you.

Here is an interesting thread on "SmartCraft Compared to NMEA-2000" from another boating forum. (If linking to other boat forums is a BABC breach of etiquette, please let me know and I will fix the problem immediately)

My [perceived] needs are merely 1) fuel flow info and 2) a more accurate gas gauge 3) access to the engine ECM data such as engine hours and water pressure (to roughly track the health of the seapump impeller), 4) low cost, and 5) easy installation. It appears that the Mercury SmartCraft system may meet all of these criteria for me.

Regarding the accuracy of the fuel flow that Mercury provides from the engine ECM (and even how that is accomplished physically), I will try and find out tomorrow by calling Mercury Marine Consumer Line at (405) 743-6566.

GFC: Yes, I agree with you that having access to fuel flow data and then using that info to run at the most cost-effective cruising speed is a great thing to have. Does your Floscan system show gal/hr and gallons used? Or does it show miles/gal? Which specific data do you find most useful? And why?

Last edited by Titanium; 03/11/09 04:36 AM. Reason: added link to "SmartCraft Compared to NMEA-2000" thread, asked GFC about Floscan

In theory, there is no difference between theory and practice. In practice, there is.

07 Cobalt 240 w/ Merc 496 Mag MPI V8 Bravo 3
05 Dodge Ram 1500 QuadCab 5.7L V8 Hemi
07 SeaDoo Wake 215, 1996 SeaDoo GTX, 05 HD Dyna SuperGlide
#454788 - 03/11/09 01:38 AM Re: To Sensor or Not, That is the Question - Fuel Flow Meter [Re: Margin_Call]  
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Margin_Call,

Thanks for sharing your experience with your SmartCraft system gauges. Did you install these yourself (and take pictures - hint hint !!) or did you have the dealer do this?

Also, when you calibrated the gauge for your 50 gallon gas tank (same size as ours) how did you start out with an empty tank? Did you actually 1) pump or siphon the fuel out until empty, or 2) did you just run the boat down to the last gallon or two and set that as "Zero Gallons" during the calibration? I guess if you did the latter, then when the SmartCraft gauge says you are at empty, then you still have that gallon or two as reserve.

I am thinking of using the SmartCraft system monitor here (the white round gauge at the right).

This shows a good price on a SC1000 System Monitor at eBay for $150 ($163 delivered).

After more reading, it appears all I need for this installation is the SmartCraft SC1000 System Monitor and the appropriate length of data harness. I will know for sure after consulting with Mercury Marine tomorrow.


In theory, there is no difference between theory and practice. In practice, there is.

07 Cobalt 240 w/ Merc 496 Mag MPI V8 Bravo 3
05 Dodge Ram 1500 QuadCab 5.7L V8 Hemi
07 SeaDoo Wake 215, 1996 SeaDoo GTX, 05 HD Dyna SuperGlide
#454789 - 03/11/09 05:52 AM Re: To Sensor or Not, That is the Question - Fuel Flow Meter [Re: Titanium]  
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Titanium;

Sounds as the Smartcraft system may meet your needs, so there is no need to re-invent the wheel, as it were. I'd go with that.

My engines are Gas not Diesel; however, they employ a return-line-to-tank fuel system, which is similar to diesel engines, in that not all of the gas pumped into the engine is used, but some is returned to the tank.

For that reason, the fuel flow system must have a sensor on both the supply and return lines, so that the return reading can be subtracted from the supply reading.

I have run across three solutions for this. One made by Albatross Systems, is a NMEA2000 system that connects to both sensors and does the subtraction. Unfortunately, I am having a hard time in finding an importer, as they are made in Spain.

The second solution is from FloScan. They make an analog gauge, probably not unlike the one GFC has, however, the version I need will also do the return-line subtraction. But since this is an uncommon setup, the gauges are special order from the factory, and I need two of them for $600 each, and no networking capability exists. The single sensor gauges for engines without a return line is normally half that cost.

The third solution is also from FloScan, and they have a NMEA2000 Diesel system. I have confirmed with FloScan that they will work with my Gas setup as well. These are normally about $1,200 each and I need two of them, so I have not been too keen to install the system.

But we want to use the boat significantly more this year, as we'll be in retirement and can spend a lot of time aboard. I have found prevously that just a couple hundred RPM change in the engines can result in a 50% difference in burn rate. Last year, if I went at 3,000RPM, I was getting a paltry 0.5MPG, and if I upped to 3,400RPM, I got about 1MPG. One MPG seems terrible, until compared to 0.5MPG, I guess.

This is crazy drastic, so I don't dare go too far at today's fuel prices without getting the best fuel economy. This is one reason we have not taken a long trip with the boat yet.

Since I am committed to install a system this year, I contacted FloScan last week, and got a pretty good discount on the NMEA2000 system , and it ended up costing not much more than the analog gauges. So I ordered them last week, and since they are special order as well, they have about 2 weeks lead time, so I will get them in time for boating season.

I have to state one huge issue between between Smartcraft and NMEA2000. Smartcraft is a properitary system, while NMEA2000 is an open system. Other manufacturers in other industries have tried this, and its my opinion that while they may be successful in the short term, they eventually all lose. Its happened countless times before.

As only one manufacturer produces SmartCraft, and literally dozens of manufacturers work with the NMEA2000 standard, its not hard to see the final outcome.

Its yet again the old BetaMax/VHS scenario.

But if you already have a SmartCraft system, or SmartCraft capable, I would not rip it out, as it makes sense economically to stay with what you already have.


President and CEO - Napmoor and Doolittle.


2004 Mercury 270 Dinghy.
2016 Grand Design Reflection 29RS 5th Wheel
2016 GMC Sierra 2500HD SLT 6.6L Diesel

previous boats:
1995 Carver 325
1999 Four Winns 268
1999 Four Winns 225
1996 Rinker 180
#454807 - 03/11/09 11:42 AM Re: To Sensor or Not, That is the Question - Fuel Flow Meter [Re: Al]  
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Al,

Congratulations on your impending retirement. When is the blessed event?

The return-line-to-tank system, which require two sensors, sounds like an expensive nightmare. What kind of output are the individual sensors? Is the sensor output something that you could manipulate yourself and do the substraction, and then feed that result into the normal fuel flow monitoring system?

And I wonder what the diesel engine guys do to solve this fuel flow problem? Or are they just resigned to forking over $1200 per engine?
Quote:
at 3,000RPM, I was getting a paltry 0.5MPG, and if I upped to 3,400RPM, I got about 1MPG. One MPG seems terrible, until compared to 0.5MPG, I guess.


That is an outrageous difference in miles per gallon. No wonder you don't travel very far. Although you certainly will do better this summer than last summer, given that gas prices appear to be much more reasonable this year.

Quote:
I contacted FloScan last week, and got a pretty good discount on the NMEA2000 system , and it ended up costing not much more than the analog gauges.


Way to go on the Floscan discount! Are they just slow like everyone else in today's economy, and thus willing to cut deals? Or are they hoping to get good reviews on an upcoming article? nono laugh

Quote:
Smartcraft is a properitary system, while NMEA2000 is an open system. Other manufacturers in other industries have tried this, and its my opinion that while they may be successful in the short term, they eventually all lose. Its happened countless times before.

As only one manufacturer produces SmartCraft, and literally dozens of manufacturers work with the NMEA2000 standard, its not hard to see the final outcome.


I fully agree with you regarding eventual outcome of SmartCraft versus NMEA2000. Mercury is indeed being short-sighted.

Although, if I was Mercury, I would have an end-game such that future versions of SmartCraft would become NMEA2000 compliant. At this point, Mercury's SmartCraft systems appeared to have beat NMEA2000 to the market by around 4-6 years, and while limiting to the end-user, at least allowed Mercury to grab some sales and [temporary] marketshare.

On a separate note, let me ask you the same questions I asked GFC: Will you use gal/hr and total gallons used? Or will you use miles/gallon?

On future research last night, it appears that the SmartCraft SC1000 System Monitor can only Fuel Used, Gal/Hr, and Range, while the SmartCraft Tach/Speedo dual gauges can do true Miles/Gal. So I may have to drop $400 on the two gauge system as versus $150 just the single System Monitor gauge (not counting the crazy expensive system harnesses at $40-$70 depending on length). But it may still be Ok in that the Tach/Speedo combo really do look a lot better than the System Monitor (round white item at right) .

Last edited by Titanium; 03/11/09 11:50 AM. Reason: MPG question; more info on SmartCraft options

In theory, there is no difference between theory and practice. In practice, there is.

07 Cobalt 240 w/ Merc 496 Mag MPI V8 Bravo 3
05 Dodge Ram 1500 QuadCab 5.7L V8 Hemi
07 SeaDoo Wake 215, 1996 SeaDoo GTX, 05 HD Dyna SuperGlide
#454810 - 03/11/09 12:29 PM Re: To Sensor or Not, That is the Question - Fuel Flow Meter [Re: Titanium]  
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Titanium - just a side note to your question of where to start fuel-tank wise once you've installed your system of choice. You don't start with an empty tank, you start with a full tank, run for an afternoon or so, then refill and compare what you physically pump in to what the flow meter reads as used. This is usually the calibration method that most (if not all) fuel flow sensors use.

I agree with GFC on the usefullness of the meter. I tend to look at MPG when cruising. I can't remember my sweet spot off hand, but it does vary some depending on your load that day. I went so far as to take a ride after I filled up one day and mark the MPG and GPH on a piece of paper at 500 rpm intervals. I'd run for maybe 5 minutes at each rpm level so it had time to get a more accurate reading. That'll show you your best cruise rpm and maybe open your eyes about consumption vs. rpm's.

Just a couple thoughts...


2005 Monterey 302
#454821 - 03/11/09 02:53 PM Re: To Sensor or Not, That is the Question - Fuel Flow Meter [Re: Duke]  
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Al Offline
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Titanium;

Retirement: June 30, 09 is the official date, but I am going to use up some of my vacation time in May and June, so I'll be at work for 3 days a week beginning the first of May, until the end.

I am sure I will use the MPG calculated feature.

Yep, diesel guys got to spend more money.

One of my dock mates bought a 2007 holdover 44ft SeaRay express cruiser last year, with diesel engines. I can't remember the engine brand, but it did have a SmartCraft system on board. He also had a MFD with a Maptech radar - I didn't know they even made one. I think it was a SeaRay Navigator system or something like that. The thing that struck me odd is that the MFD was a Microsoft Windows application, and had embedded XP in the MFD. Took about 3 minutes to boot.

I believe the Flowscan fuel flow sensors are pulsed, not unlike a tachometer. If they produced a proportional voltage, it would be easy, I think, to subtract one voltage from the other. But since it is a number count, I think there will need to be some logic to do this.

Duke! where you been, man!


President and CEO - Napmoor and Doolittle.


2004 Mercury 270 Dinghy.
2016 Grand Design Reflection 29RS 5th Wheel
2016 GMC Sierra 2500HD SLT 6.6L Diesel

previous boats:
1995 Carver 325
1999 Four Winns 268
1999 Four Winns 225
1996 Rinker 180
#454833 - 03/11/09 04:54 PM Re: To Sensor or Not, That is the Question - Fuel Flow Meter [Re: Al]  
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Al,

So you are definitely a short-timer at work then.

Quote:
I believe the Flowscan fuel flow sensors are pulsed, not unlike a tachometer. If they produced a proportional voltage, it would be easy, I think, to subtract one voltage from the other. But since it is a number count, I think there will need to be some logic to do this.


I did some quick searching and it looks like these might do the trick. These look like the same item, but the second source may be less expensive.

http://www.laurels.com/totalizer.htm

http://www.electronumerics.com/micro/micro_totalizer.htm


In theory, there is no difference between theory and practice. In practice, there is.

07 Cobalt 240 w/ Merc 496 Mag MPI V8 Bravo 3
05 Dodge Ram 1500 QuadCab 5.7L V8 Hemi
07 SeaDoo Wake 215, 1996 SeaDoo GTX, 05 HD Dyna SuperGlide
#454855 - 03/11/09 08:44 PM Re: To Sensor or Not, That is the Question - Fuel Flow Meter [Re: Titanium]  
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Originally Posted By: titanium
GFC: Yes, I agree with you that having access to fuel flow data and then using that info to run at the most cost-effective cruising speed is a great thing to have. Does your Floscan system show gal/hr and gallons used? Or does it show miles/gal? Which specific data do you find most useful? And why?

My boat has gas engines and I have this Floscan gauge (in white). It gives me an instant readout on GPH per engine and also totalizes the fuel consumption. It's VERY accurate on total consumption--when I fill up and take on 200~ gallons the Floscan is always within a gallon of total consumption. There's that much error from one fillup to the next so I figure it's dead on.


It shows gph but does not show mpg. I came up with an Excel spreadsheet (Shown Below) where I input the speed at every 200 rpm's from idle speed up to 5,000 rpm's. I also input the gallons per hour on each engine. As you can see on the spreadsheet I made this spreadsheet for river use. I made one run upstream and a second run downstream and entered the data. The spreadsheet averages the two speeds and uses that calculation (along with gph) to compute MPG.

The spreadsheet then graphs the MPG at various rpm's and also the average MPH at each of those rpm's. (the spreadsheet is shown below as two pages. It's all one one page but was too long to post here)




If anyone wants a copy of the spreadsheet, please submit $15,000 to the president of Nigeria. He will cash your check, send you the Excel file and return to you a sum of $250,000,000 because he needs your help moving large sums of money out of Nigeria. thumb wink

Actually, if anyone wants a copy of the spreadsheet just let me know your email address. It's pretty simple to figure out and fun to use.

By the way, I found I'm getting right at 1mpg (+/- .05) at idle speed, slightly above idle, then all the way from about 3200-4000 rpm's. Between those ranges the boat is transitioning from being at displacement speed to being on plane. Above that 4,000 rpm number the secondaries are starting to open on the carb and fuel economy goes down.

Originally Posted By: Al
But we want to use the boat significantly more this year, as we'll be in retirement and can spend a lot of time aboard. I have found prevously that just a couple hundred RPM change in the engines can result in a 50% difference in burn rate. Last year, if I went at 3,000RPM, I was getting a paltry 0.5MPG, and if I upped to 3,400RPM, I got about 1MPG. One MPG seems terrible, until compared to 0.5MPG, I guess.

Al, above displacement speed and below the speed where your boat is on plane it is plowing through the water and burning a lot of fuel. Once it gets on plane your fuel consumption will be fairly constant until you get up into high rpm's (4,000-4,500 and up).


"Beachcomber" 1995 Sea Ray 550 Sedan Bridge


Anchor's down......Bottoms Up!
#454865 - 03/11/09 10:03 PM Re: To Sensor or Not, That is the Question - Fuel Flow Meter [Re: GoFirstClass]  
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GFC - you were nice enough to email that to me 3-4 years ago and I still use it. Thanks!


2005 Monterey 302
#454868 - 03/11/09 10:28 PM Re: To Sensor or Not, That is the Question - Fuel Flow Meter [Re: GoFirstClass]  
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GFC,

Very nice job on the spreadsheet. I gather that you put this spreadsheet together to be able to calculate an MPG curve. But isn't this data only good for only one load configuration?

Quote:
As the load on my boat changes due to more/fewer passengers, fuel and water loads, etc., I have to change my cruise rpm's. As I change throttle positions I can monitor the flow of fuel and find a sweet spot to cruise at.


I'm still unclear (my fault - not yours) on how you use the Floscan to decide where to move your throttle that 200-300 RPM (I'm guessing on the amount) away from your spreadsheet calculated "sweet spot" RPM.


Duke,
I'm fairly new here only having found my boat in Feb 2007. In fact, the gang here at BABC helped walk me through the options and prices on my boat before we even bought it. I haven't seen you around until just recently? Kidnapped by aliens? laugh

Thanks for sharing how you calibrated your fuel flow meter. From the SmartCraft directions, it appeared that the calibration was only done at four points - 0%, 25%, 50%, and 100%. It sounds like your fuel flow meter calibration was able to use more calibration points (since you could add any amount of fuel)?


In theory, there is no difference between theory and practice. In practice, there is.

07 Cobalt 240 w/ Merc 496 Mag MPI V8 Bravo 3
05 Dodge Ram 1500 QuadCab 5.7L V8 Hemi
07 SeaDoo Wake 215, 1996 SeaDoo GTX, 05 HD Dyna SuperGlide
#454874 - 03/11/09 11:28 PM Re: To Sensor or Not, That is the Question - Fuel Flow Meter [Re: Titanium]  
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Pasco, WA
Originally Posted By: Titanium
GFC, Very nice job on the spreadsheet. I gather that you put this spreadsheet together to be able to calculate an MPG curve. But isn't this data only good for only one load configuration?

Yes, but load factors won't change your throttle settings that much. For my boat, if I'm running empty (low on fuel and water, no passengers, etc.) I can easily plane at 3200 rpm's. When I'm running with full fuel and water, a few passengers, food, etc., I have to run about 3800-4000 to stay on plane.

Once you really learn your boat you will be able to feel the sweet spot even as your load changes. If your rpm's are too low the stern starts to squat in the water, the engine sounds different and the boat will feel sluggish. When that happens move the throttle up a bit (200~ rpm's) and it should improve. If it's still squatting, up the rpm's again until you feel the boat smooth out.

Originally Posted By: GFC
As the load on my boat changes due to more/fewer passengers, fuel and water loads, etc., I have to change my cruise rpm's. As I change throttle positions I can monitor the flow of fuel and find a sweet spot to cruise at.

When my boat gets smoothly on plane I check the Floscan gauge. If it seems on the high side I'll back the throttles off a bit. If the boat still is easily on plane I'll watch the gauges and see if I'm having any effect on the GPH. If I back off the throttles too far I'll see the bow rise as the stern settles and I'll give it a bit more gas.

Originally Posted By: titanium
I'm still unclear (my fault - not yours) on how you use the Floscan to decide where to move your throttle that 200-300 RPM (I'm guessing on the amount) away from your spreadsheet calculated "sweet spot" RPM.

Again, that will come to you when you get to learn the feel of the boat. When you have an I/O you will get the feel for trimming it. Most likely the trim will be all the way down when you put it in gear and take off. As it transitions from being "IN" the water (at displacement speed) to being "ON" the water (at planing speeds) you will learn to simultaneously raise the trim and back off the throttle. As it settles nicely on plane you can bring up the trim a bit more and back off on the throttle to get to that real sweet spot. You will learn to recognize that sweet spot by the sound of the engine. When it's properly trimmed the engine pics up rpm's, the speed picks up and the boat is really running nicely.

When you master that you will become one with your boat and it all becomes clear. You only get to that point through lots of time spent on your boat practicing those things.

What a horrible thing to have to look forward to..."Honey, I really need to take the boat out this afternoon so I can get more practice with the throttle and trim." laugh laugh laugh

Originally Posted By: Duke
GFC - you were nice enough to email that to me 3-4 years ago and I still use it. Thanks!

thumb You are most welcome Duke. Glad to be of help!! thumb


"Beachcomber" 1995 Sea Ray 550 Sedan Bridge


Anchor's down......Bottoms Up!
#454881 - 03/12/09 02:41 AM Re: To Sensor or Not, That is the Question - Fuel Flow Meter [Re: GoFirstClass]  
Joined: Jan 2003
Posts: 15,089
Al Offline
Nautical Alchemist
Al  Offline
Nautical Alchemist
Grand Poobah

Joined: Jan 2003
Posts: 15,089
Vagabond Wanderer from Mich.
GFC;

I had a fuel flow meter on my last boat, and I know what you mean about pre-planing, as the worst fuel mileage was just before the boat broke plane. And as you state, it was rather constant under plane, until reaching higher speeds. This seems to be the normal characteristic, and what I had expected with the Carver.

However, at both 3,000 RPM (0.5MPG) and 3,400 RPM (1.0MPG), the boat is well under plane. The boat breaks plane at about 12 MPH, and at 3,000 RPM, the boat is doing about 17 MPH, and at 3,400 RPM, I am doing about 21MPH.

I am not sure what is causing the huge difference, other than the boat has inboards, and there seems to be a rather large difference in angle-of-attack, depending on the RPM, and the boat may be rather sensitive to the trim tabs as well, as they are quite large.

I know that you have inboards as well, so maybe its due to the fat hull design, because the boat seems real sensitive to changes in RPM.

Anyway, something is going on that I am not able to explain, as this boat seems to defy the normal characteristics you experience on your boat, and I experienced with my last boat. So I figure to find a rather significant change in economy with the use of the meters. I'll be darned interested to find out what the characteristics are.

Regardless, it seems fuel flow meters for this boat will be well worth their cost.

By the way, I cannot use the same FloScan gauge you are using, as that one will not do fuel-return type engines. I would have needed two of these, and I was struggling with finding dash space, as they are 3" gauges:



(they look like model 5500, but are in reality model 5800, for fuel-return systems)

So I ended up ordering the NMEA2000 interfaces from FloScan. As I like pictures, here is what the FloScan NMEA2000 devices look like:


While you can read the data directly from the display, its intent is to read from a NMEA2000 display unit of your own choosing.

I have three displays I can use; a RayMarine C-80 MFD, my Garmin GMI-10 data display, or my Lowrance LMF200 display unit. GPS data gets pumped into each gauge via the NMEA2000 network, so I can read fuel data from either display, either simultaneously, or independently, simply be selecting that function for each unit.

But due to the almost standard nature of NMEA2000, FloScan tells me that the RayMarine can only display combined fuel flow data, while the Garmin and Lowrance units can display fuel flow data for each engine independently.

The Garmin manual indicates it can display:

Fuel Flow Rate (I assume GPH)
Cruising Range
Fuel Economy (I assume MPG)




Garmin GMI-10 NMEA0183/NMEA2000 general purpose display unit. Can display a dozen or so pages of NMEA data. The gauge is a 4" unit.



RayMarine C-80 MultiFunction Display. Displays GPS, Chartplotter, Radar, Sonar, and Engine parameters on pages or split-screens. The screen is 8" diagonal, so a lot of data can be shown.


Lowrance LMF200, low cost NMEA2000 display. Displays speed, depth, fuel, trim tabs, temperature, and other data from the NMEA 2000 network on a dozen or so pages. Similar in function to the Garmin unit, but is monochrome, and a smaller 2" gauge (and a lot cheaper).

Titanium;

If you are looking into a separate fuel flow gauge, the two cheapest methods I know of are;

1. Lowrance LMF-200 gauge and fuel flow probe.
2. NorthStar F210 fuel flow gauge.

Both are suitable for carb or EFI engines that have a single fuel line to the tank, which I believe includes most MerCruiser and Volvo gas engines. Both will set you back about $150 or so, so its probably the lowest cost option.

On my last boat, I had a Standard Horizon fuel flow gauge, which essentially was a clone to the NorthStar fuel flow gauge, and it provided GPH, but there was no NMEA0183 or NMEA2000 interface. NorthStar used to be known as NavMan.

The Lowrance gauge on the other hand is a bonafide NMEA2000 system, and you can buy a package deal with the fuel flow probe that also contains all of the cabling to setup a basic NMEA2000 network. If you want to get into NMEA2000, this is by far the cheapest method to do so.

If you pump GPS information into the NMEA2000 network, I believe (but would have to confirm), that the LMF200 would display GPH as well. But for sure, the LMF200 will display other NMEA2000 data, such as Bennett trim tab position, fuel tank levels, speed, depth, and several other parameters, providing you have the appropriate sensor.

I have a LMF200 on my boat as one of three different NMEA2000 displays, and for the price of the unit, there is a lot of value.

One caveat though, the NorthStar and Lowrance transducers, compared to FloScan's, are rather cheap looking. The FloScan unit is made of metal, with metal fuel barbs, whereas the NorthStar and Lowrance versions have cheap looking nylon fuel barbs. However, to my surprise, I never had any fuel leak problems with the unit on my old boat.

If you have not noticed, this is an area that I have a lot of interest in...


President and CEO - Napmoor and Doolittle.


2004 Mercury 270 Dinghy.
2016 Grand Design Reflection 29RS 5th Wheel
2016 GMC Sierra 2500HD SLT 6.6L Diesel

previous boats:
1995 Carver 325
1999 Four Winns 268
1999 Four Winns 225
1996 Rinker 180
#455020 - 03/14/09 10:57 AM Re: To Sensor or Not, That is the Question - Fuel Flow Meter [Re: Al]  
Joined: Apr 2007
Posts: 618
lorenbennett Offline
Admiral
lorenbennett  Offline
Admiral

Joined: Apr 2007
Posts: 618
Golden Valley, AZ
My 03 searay has smartcraft enabled but no display and they are very expensive. I already wanted gps, chart, and radar so I bought lowrance and just added the the sensor for $90. The only reason I added it is for the offshore fishing trips. I it really gives me peace of mind knowing what I have used and what I have left. thumb


2003 Searay 260 Sundancer
"Entertaining Angels"
2000 Ford f350 Dually with 7.3L
#455053 - 03/15/09 03:11 AM Re: To Sensor or Not, That is the Question - Fuel Flow Meter [Re: Al]  
Joined: Feb 2007
Posts: 971
Titanium Offline
Admiral
Titanium  Offline
Admiral

Joined: Feb 2007
Posts: 971
Northern California
Al,

I kept thinking about statements regarding Mercury SmartCraft being a proprietary protocol, and the resulting probable negative future. What about a gauge that talks both SmartCraft and NMEA-2000? d And for good measure, these Faria MG2000 gauges also speak J1939, J-1708 and K-line.



http://www.faria-instruments.com/marine/mg2000.php

The image above is kind of goofy with the red outline in the bezel, but I believe that Faria makes a variety of gauge bezels for the MG2000 line. It is not exactly clear from the Faria website.

I have a call into Faria to see if they are able to match the helm analog gauges that Faria made for Cobalt for my 240, and incorporate that bezel into the MG2000 line. Or at least get something close that will match my existing gauges.

Here are pictures of my present gauges. The gauges are made by Faria, have silver lettering on a black background with a chrome trim ring. The big three gauges in the center are, from left to right:

a) 0-65 MPH speedometer
b) electronic compass
c) tachometer




I must admit that I like the look of the gauges (shown below) that Cobalt used for 2002-?? better than the gauges on our 2007. frown





In theory, there is no difference between theory and practice. In practice, there is.

07 Cobalt 240 w/ Merc 496 Mag MPI V8 Bravo 3
05 Dodge Ram 1500 QuadCab 5.7L V8 Hemi
07 SeaDoo Wake 215, 1996 SeaDoo GTX, 05 HD Dyna SuperGlide
#455056 - 03/15/09 05:15 AM Re: To Sensor or Not, That is the Question - Fuel Flow Meter [Re: Titanium]  
Joined: Jan 2003
Posts: 15,089
Al Offline
Nautical Alchemist
Al  Offline
Nautical Alchemist
Grand Poobah

Joined: Jan 2003
Posts: 15,089
Vagabond Wanderer from Mich.
My guess is that Faria has licensed Smartcraft from Mercury (or maybe they are a Brunswick company?).

At any rate, I see they do several kinds of standard protocols, including ALDL and J-1939, which might be SAE?

I saw that they did NMEA2000 but I am guessing it is limited to engine data. I guess maybe that might be one big difference between NMEA2000 and SmartCraft in that engine monitoring is only a small part of NMEA2000, while (and I might be incorrect), I always thought that SmartCraft was mostly engine data.

I have seen earler versons of those gauges before, on one of the marine electronics blogs, and thought they were pretty neat.


President and CEO - Napmoor and Doolittle.


2004 Mercury 270 Dinghy.
2016 Grand Design Reflection 29RS 5th Wheel
2016 GMC Sierra 2500HD SLT 6.6L Diesel

previous boats:
1995 Carver 325
1999 Four Winns 268
1999 Four Winns 225
1996 Rinker 180
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