Remote Fuel Gauge

[supersailor]

It's raining out so I finally sat down and figured out how to shrink my photos. Hence this post on one of my latest and most satisfying improvements that is a remote, accurate fuel gauge. The 34-2 has a 30 gallon fuel tank located under the rear double berth. The tank is as shapely as the boat and it goes from the hull to the bottom of the berth. a "cut out" with a three inch drop allows the fuel fill, vent, fuel pick up and gauge. Not a great feature but it allows 14.5 gallons more fuel in that location. The checking of the gauge was a real pain involving picking up the bunk cushions, moving a large hatch then looking at a wildly inaccurate gauge that read full at 1/2 tank and nearly 1/2 when it only had 2 gallons left.

After looking at the many possible senders, I settled on a Centroid Programable unit. It was $60.00. I was given a choice of measuring the tank in eights by emptying it or by having the Engineer Joel measure it based on the factory drawing I provided for $110.00. Bending over the tank pouring measured amounts of fuel into a little hole then measuring it with a tape measure was utterly unappealing so I sprang for the Engineer measure. The results were quite interesting. The bottom 3" of the tank holds 1 gallon while the top 3" holds 14.5 gallons. That means the sender does not start sending until the tank is half full. Joel suggested that I make an adapter that raises the sender 2". The sender is 7/8" thick and add two gaskets and the sender is right at the bottom of the bunk. I had a local machine shop make the 2" spacer out of aluminum. The sender can now read 25.7 gallons and I had him program the sender so that it is accurate based on the 30 gallons the tank holds. The sender does not read the last 1 gallon. That is my reserve. Because the sender sends a voltage reading to the gauge, I used a Westach 2C7V gauge from Aircraft Spruce and Specialty Company, Corona, California . It has a cute little set of wings on it.

Anyone with a 34-2 can contact Joel directly at joel7@cfl.rr.com and order a sender just like mine for $60.00. This solution would also work for the 32-3, the 35-3 and the 38 but I think the sender would have to be calibrated to your tank ($110). My factory manual has a scale drawing of the tank in it so I think yours will also.

If anyone is interested, I have the calculations for the 34-2 tank from Joel showing the tank capacity at .25 gal intervals. Send me a private e-mail at rwm91@hotmail.com and I'll send them to you. They are kind of bulky for a general post.

 

[EGregerson]

sender pickup

Wow; That is a great fix to the problems. My fuel pickup came unsoldered back when; took a while to find out the source of the problem. Just waiting for it to come unsoldered again. Looks like a Centroid will solve that. And i would luv a gauge somewhere other than under the mattress. I'll use your example if that's ok. Great job.

 

[supersailor]

Please feel free to use the info. The new gauge has been in the boat for a season now and the results are wonderful. You have some choices where to put the gauge. It can be at the Nav Station or at the instrument panel. I liked it indoors. Another choice is whether to pick up the power for it at the Panel or at the Engine. Picking it up at the panel is convenient but does require you to turn it off after you read it (a switch at the panel). At the engine does the automatic turn off but the ignition has to be on to read it. I did have to make my own lower gasket. Welding it would have been better but that opens a whole new can of worms.

The tank has been reading quite accurately starting at approximately 27 gallons. Prior to this change, I didn't even bother to check the gauge as it was wildly inaccurate. I had a scrap of paper tucked above the electrical panel with the hours at refill and the approximate hours when I would have to start rowing.

 

[Tom Metzger]

My 1987 E-34 is much younger than Bob's... #234 , and the fuel gauge is located on the top of the tank. This gives it much more accuracy.

The drawing in my manual and on this site show it correctly.

I have no idea why they would have located the gauge in the middle of the tank vertically.



Speaking of aft cabins, my son's former PS/E-333 had the aft cabin cushion split fore and aft which made it much easier to work with.

 

[Christian Williams]

The prudent mariner expects a pretty accurate fuel gauge. On selling a boat, most buyers will say, "what? no fuel gauge?" We are used to them in cars, where I routinely run them down to below the line (analog) and recently, below zero (digital). In the past five years I have run out of gas three times by pushing the limit. When I ran my Prius out of gas last summer at th Virgin River, just north of Las Vegas, it was 110 degrees and I waited an hour for help. Whenhelp arrived I remarked that it was ridiculous to run out of gas in a Prius, getting 47 mpg. The driver said that the model people most run out of gas is the Prius. "Go figure." He meant that Prius drivers are very aware of their mileage. And also, idiots. Because a gas gauge is not a personality, or object of intimacy.

But an operative fuel gauge on a boat is expected and normal, comforting and rational, and gives everybody on board confidence we will get where we're going. What could be an argument against a fuel gauge? None, really. However....

In general aviation, fuel gauges are considered murderous little killers installed on the panel. It is because in an airplane what usually kills you is running out of fuel, not engine failure or "air pockets." A fuel gauge is the definition of pilot error: he thought he had enough fuel; he was alert to his gauges; his panel scan was beyond reproach; his funeral is Tuesday.

Boats that run out of fuel don't kill you, so the analogy is ridiculous. Neither do cars. So, why not go to a little trouble to have an operative fuel gauge on a sailboat?

No reason not to, at all. Except....

Why is a fuel gauge necessary? A simple plot of fuel burn is very accurate, whether your diesel burns half or three-quarters an hour. It's in the log, where we need to keep the record of our engine hours. And an engine hour-meter, or Hobbs meter, is much more important that a fuel gauge, because it suggests intervals of oil changes and so on.

But isn't a fuel gauge necessary to tell you how much fuel you currently have? Even if 90 percent accurate, that's a big help, isn't it?

Sure. But most of us burn hardly a tank of diesel a summer. And since our tanks don't leak, it is pretty obvious that they are usually well filled. We only think about taking on diesel "after a while." And then the diesel we take on is usually much less than we predict to the fuel-dock attendant, who is irritated to stretch out a 50-foot hose to give us 6 gallons, while a 400-gallon customer waits.

Is this a sneaky attack on fuel gauges in boat? Of course not. Fuel gauges on a sailboat make obvious, rational sense, and everybody ought to have one.

But why?

So you can run the tank down to empty, like I do with cars? No, no, no, we never do that. We should keep the tank pretty full, so tropical fish don't start spawning in a condensation environment.

So, if we are not intending to run the tank down below quarter-full, why is a fuel gauge important?

Because it provides at glance the level of fuel in the tank!

But why need such a glance if the log tells the fuel burn accurately?

Because you can't remember when you last took on fuel, or how much is left, and the gauge tells you that?

Oh.

Well, if you can't remember how much fuel you have, then a gauge is a good idea.

And they are accurate, until they're not.

 

[Alan Gomes]

Moeller mechanical gauge

A Moeller mechanical gauge such as this is nearly foolproof and a cinch to install: http://www.jamestowndistributors.co...l_fuel_gauge&gclid=CJPok9LgjsoCFcVffgodMakEGw

Of course, this assumes that you have reasonable visual access to the top of your fuel tank. In my own case, the tank is quite visible immediately aft of the engine. My engine uses so little fuel that I need to check the level only occasionally. When I've got the companionway steps out to verify the belt tension and oil level I just take a quick glance at the fuel gauge.

Going by engine hours is another method, but I've had more than one hour meter crap out on me. Plus, going by engine hours assumes that you have topped off the tank completely so that you are starting from a known full tank and hence a known amount of fuel. I fill my tank using a jerry jug at the dock and I tend not to want to run the risk of overfilling in order to avoid spills, so I usually don't fill it more than 80% or so. (I'm also not convinced that the conventional wisdom about keeping tanks fully topped off all the time so as to avoid condensation is correct, so I'm not worried about that aspect. http://forums.sailboatowners.com/index.php?threads/is-fuel-polishing-snake-oil.145679/#post-959416)

Anyway, these mechanical gauges are cheap, simple, and reliable. But they are also useless for installations where the fuel tank remains inaccessible.

Edit: Somehow I missed Tom's post above before writing this. It appears that we are talking about the same hardware.

 

[Christian Williams]

I could sound the tank with a stick on the 32-3 in 30 seconds. Lift quarterberth cushion, spin off inspection plate with the key, dip stick, replace plate.

Not all boats make it that easy....

 

[supersailor]

Christian, Doesn't work on the 34. Attempt to hold the giant double cushion back while moving a huge hatch that is the size of the top of the tank out of the way and read gauge that reads full at a half of a tank. What's an inspection port? Is that when you take off the gauge and dump 14 gallons of diesel in the bilge? The tank in the 34 is not one of the better things that Ericson did. :0

 

[Jason G]

My 87' E34-2 is SN 203. The original tank was replaced with a new aluminum one made up from 1/8" sheet and baffled inside. Same external dimensions as the original tank. The mounting tabs were beefed up too. The mechanical gauge was removed (may have not been there to begin with) and I have an electrical one installed next to the fuel pick up and return ports. It's not all that accurate and I may see about getting one of these programable calibrated senders for my boat. I have an unused port that I can dip the tank with if I've burned the first 5-7 gallons off the top.

Jason

 

[Rick R.]

It was a Mystery To Me......

But not anymore.

Back when we first bought our boat, I removed the fuel gauge from the tank only to discover that it had no wires, no float, no visible mechanical means of indicating the fuel level. In fact, you'll see a thread started by me back then, I was as mystified as I was when I first heard music coming out of my parents stereo system, how'd Nat King Cole get inside that thing?

I went to WM and found a direct replacement gauge, the Moller Direct Site Fuel Gauge and installed it. Funny thing is, since we keep a detailed log of engine hours each day as well as a log of when we last filled the tank, I haven't looked at that gauge more than twice in the past five years. We keep the tank full as much as is possible.

Now here's the good news revealed by keeping detailed logs, we discovered that our fuel consumption is much less than a 1/2 gallon per hour!