Fuel Flow Guages

LandVF36 · Post by **LandVF36** » Tue Sep 02, 2008 11:35 pm

Has anybody installed fuel flow guages. I purchase a Lowrance LMS-520c GPS/finder this spring which can mointor their EP-60 fuel flow guages.

I installed two last weekend. Starboard seemed fine at .8 GPH at idle. At 1500 RPM, about 1.7 GPH. At 3300 RPM, about 14 GPH when trimmed out and moving at about 27 MPH. The port guage was nuts. Sometimes showing 5-6 GPH at idle. Once over 1500 RPM, seemed to track with Starboard engine. Then over 2500, we crazy showing 25+ GPH!

I know the readings were not right on the port or that gas tank would drain at 2-3x of the other. I think I'll take out the flakey one and return it for a warranty exchange.

Just wondering if anyone else has tried these or other brands.

Stripermann2 · Post by **Stripermann2** » Wed Sep 03, 2008 8:10 am

I have Flowscans but have not installed yet.

We'll see when I get around to installing. Keep us updated on your progress, good luck.

jakevr · Post by **jakevr** » Wed Sep 03, 2008 12:10 pm

what do you have for motors? im thinking about installing these

Stripermann2 · Post by **Stripermann2** » Wed Sep 03, 2008 1:28 pm

jakevr wrote:what do you have for motors? im thinking about installing these

Who are you asking???

I have Crusader 270s (small block Chevy, 350 CID)

Safari · Post by **Safari** » Wed Sep 03, 2008 3:13 pm

Due to the amount of labor involved with this type of installation, I would have to recommend Floscans - it is a bit more expensive up front, but when something goes wrong, they have the best tech support. My fuel usage (f36) is around 3 gph at 1600 rpm (each engine) - at 2800 rpm, port engine is 12gph; starb engine is 16gph - 3000 rpm the fuel usage difference is more dramatic. I think something with my old distributors is messing me up. The Floscan instructions are excellent; my installation went without a hitch even though I had connected one of the senders reversed (that probably would have blown out a cheaper unit).

LandVF36 · Post by **LandVF36** » Wed Sep 03, 2008 9:00 pm

My F36 has twin GM 454s.

The first decision was to buy the Lowrance GPS and sounder. It was after the fact that I saw the fuel flow guages were available. I figured for $120, just seeing the fuel flow rate would slow me down and I'd save the $120 in a season.

Install was simple. I have copper fuel lines off the tanks. The last 18" to the input of the fuel seperators is flexible. I just cut the 18" section in half and inserted the fuel flow devices with double clamps on the in and out hose barbs. Then, I pulled the NMEA cable up the case to the bridge with the pull wire I left behind. The whole install was only about 1.5 hours. Simple install, but they just don't seem to be calibrated at all.

Curious for those of you trying the Flowscans, what was you package price installed?

ltbrett · Post by **ltbrett** » Wed Sep 03, 2008 9:33 pm

I have the Lowrance fuel flow meters and have found them to be accurate, but sensitive to electrical connections. Make certain you have good, clean connections. Lowrance also recommends you install them vertically. Mine are horizontal, but away from my fuel pumps.

Brett

LandVF36 · Post by **LandVF36** » Wed Sep 03, 2008 10:36 pm

That's interesting. The one that seems to be close to normal readings is mounted vertically. The crazy one is more or less horizontal. I missed that in the docs. Thanks

Mitch

LandVF36 · Post by **LandVF36** » Sun Sep 07, 2008 4:16 pm

That was it! I turned the fitting 90 degrees and added another foot of 3/8 line. Vertically mounted, it works much better. Then I went for a ride.

This is what I got

RPM /MPG /MPH /Port GPH /Starb GPH /Total GPH
750 /1.63 /4.74 /1.3 /1.6 /2.9
1000 /1.69 /5.75 /1.4 /2 /3.4
1250 /1.44 /7.78 /2.6 /2.8 /5.4
1500 /1.36 /8.7 /3.4 /3 /6.4
1750 /1.18 /10 /4.9 /3.6 /8.5
2000 /1.13 /10.8 /5.1 /4.5 /9.6
2250 /0.95 /11.3 /6.9 /5 /11.9
2500 /0.74 /12.8 /9.2 /8 /17.2
2750 /0.88 /17.6 /10 /10 /20
3000 /0.74 /21.3 /16 /12.9 /28.9
3250 /0.75 /26.5 /18.5 /17 /35.5
3500 /0.75 /30 /18.6 /21.4 /40

I think the differences between engine performance are mostly due to analog tach readings. I do not have a synchronizer and was doing this from the flybridge (the tach's at the lower helm seem to track much better.

Now that I have this data, big deal I guess. However, I do have one more functioning toy on the B.O.A.T. ("Break out another thou").

That is the whole point, right?

Mitch

Peter · Post by **Peter** » Tue Sep 09, 2008 6:20 pm

glad you got your problem worked out. Thank you for posting your numbers. I am surprised, that the mileage at trawling speed [displacement rather than planing] is not better. I guess, the frustration wouldn't be worth the money saved going at slower speeds.