Emergency fuel tank

[Gixer]

I’ve had a few problems recently with air in my fuel system, I’m slowly getting to the bottom of it but am thinking of rigging up a can which I can connect up to my engine in an emergency.
I don’t want to complicate my current fuel system with valves, etc, but can easily pull off the engine fuel pipe and connect another directly. This would be a matter of loosening a jubilee clip swapping a pipe and bleeding the system. I could do this hove to or under sail quite easily. The can would be mounted above the engine so should bleed quickly.
Only issue I can think of is the return which would go back to the main tank therefor the emergency can would drain faster than normal but if I’m only using it to get out of immediate trouble will this work?
The engine is only a 1gm10 in a 27f sail yacht doing day/coastal sailing.

Anyone else have this kind of set up for emergencies?

 

[pvb]

It would be better to fix the air leak problems properly. If you go for an emergency tank, plumb it permanently with a simple changeover valve - you don't want to be messing about with jubilee clips in a stressful situation.

 

[doug748]

I did this once, by going to anchor and fabricating the tank out of a large tin can. The lift pump had failed, I now carry a spare. I disconnected the pipe after the pump, connected the new pipe and lashed the can above the engine in the companionway. I could then top up the can as we went along. Sadly I still have this artifact aboard..... : - (

Use a big can, it empties very quickly. A quick and secure fixing method would be good.

.

 

[PetiteFleur]

This happened to us on a friends boat a few years ago when the engine stopped, but managed to pick up a mooring - had some badly contaminated fuel so got the spare 20l Jerry can, fitted longer fuel and return line into the cap, wrapped cloths around the 'joint' and managed to get back to our home marina. The fuel tank, which didn't have an inspection hatch, had to be removed to fully clean it it, but as it was in the keel space under the engine which had to be removed first! An inspection hatch was retrofitted.

 

[Gixer]

It would be better to fix the air leak problems properly. If you go for an emergency tank, plumb it permanently with a simple changeover valve - you don't want to be messing about with jubilee clips in a stressful situation.

Thanks, step one is to cure the air leak. I carry a spare can of diesel anyway so rigging it up as a secondary tank seems to make sense. I’m put off rigging up a changeover valve as it adds another point of failure into the fuel system, but will take your comment onboard and rethink this.

 

[ithet]

I tried this once to isolate a fuel supply fault (mid English Channel), the 10l can emptied in a few minutes. I think you will need to rig a return line to the can.

 

[Gixer]

I tried this once to isolate a fuel supply fault (mid English Channel), the 10l can emptied in a few minutes. I think you will need to rig a return line to the can.

Nothings ever simple is it, this adds complication to the system, going to take more planning.
Thanks for the info.

 

[Stemar]

There's something to be said for the old idea of a big tank in the bilges from which you pump fuel through a filter into a day tank. At least if the primary filter gets blocked, you've got the day tank to get you somewhere safe to deal with it.

 

[penfold]

There's something to be said for the old idea of a big tank in the bilges from which you pump fuel through a filter into a day tank. At least if the primary filter gets blocked, you've got the day tank to get you somewhere safe to deal with it.

And if the filter is duplex you can change it on the run. Not many MABs(or even AWBs) have space for such a set-up without robbing storage space though and fin keel boats generally don't have much room for bilge tanks.

 

[dutyhog]

I’m another who had to do this (in the Doris Mor with no wind) and found that the return line took about 5 times as much as the injectors needed, so the 20 litre can emptied very quickly.

 

[Sandy]

Nothings ever simple is it, this adds complication to the system, going to take more planning.
Thanks for the info.

But it is how your, and tens of millions, diesel engines work.

Simple solution is to find the return pipe and make sure it gets diverted to your big can.

 

[Gixer]

Really interesting feedback on the return line.
I honestly never knew so much fuel went back, I was under the impression that the engine used most of the fuel to drew from the tank.

Thanks all, I'm glad I asked as my idea for a emergency back up might not have worked how I wanted.

 

[TernVI]

Really interesting feedback on the return line.
I honestly never knew so much fuel went back, I was under the impression that the engine used most of the fuel to drew from the tank.

Thanks all, I'm glad I asked as my idea for a emergency back up might not have worked how I wanted.

How much fuel gets returned varies a lot between different engines.
In my experience, it's not much on Yanmar GMs. Just what leaks past the injectors.
Other engines are different AIUI, they seriously circulate fuel.

One thing you can do temporarily is put a clear filter after the lift pump. then you will see the air and collect it, preventing it reaching the injector pump.

The jubilee clip you intend to undo to change tanks is prime suspect for the cause of the problem!

 

[stevd]

When I replaced my flexi feed and return fuel lines from / to the tank, I made them a bit longer so I could disconnect them from the tank and place them both into what ever fuel container I have onboard at the time.

 

[stevd]

With regards to getting air into your system, I wouldn't use jubilee clips on fuel pipes. You can get specific fuel pipe clamps made from 316 stainless steel to the size / diameter of your lines, which will clamp the small fuel line evenly unlike small jubilee clips and thus not distorting the shape of the line allowing air to get in.

I also used Hylomar Blue on the threads of any hose tails fittings and changed all of the copper crush washers for good quality new ones - this resolved the air leak issues that I had.

 

[Gixer]

I've got the hump with the air leak now so have employed a marine engineer to go though my system.
I know it goes against the PBO mentality but I've got enough other stuff to worry about

 

[B58]

I’ve had a few problems recently with air in my fuel system, I’m slowly getting to the bottom of it but am thinking of rigging up a can which I can connect up to my engine in an emergency.
I don’t want to complicate my current fuel system with valves, etc, but can easily pull off the engine fuel pipe and connect another directly. This would be a matter of loosening a jubilee clip swapping a pipe and bleeding the system. I could do this hove to or under sail quite easily. The can would be mounted above the engine so should bleed quickly.
Only issue I can think of is the return which would go back to the main tank therefor the emergency can would drain faster than normal but if I’m only using it to get out of immediate trouble will this work?
The engine is only a 1gm10 in a 27f sail yacht doing day/coastal sailing.

Anyone else have this kind of set up for emergencies?

If you have an air leak try looking at the fibre seal at the top of the fuel filter, as the bleed screw is aluminium, they can draw air, you could replace the bleed screw but use a copper washer.

Yanmar did offer a gravity tank instead of drawing fuel in via the pump, you could make your own ad use it as a day tank, drawing fuel from the main tank.

With regards to getting air into your system, I wouldn't use jubilee clips on fuel pipes. You can get specific fuel pipe clamps made from 316 stainless steel to the size / diameter of your lines, which will clamp the small fuel line evenly unlike small jubilee clips and thus not distorting the shape of the line allowing air to get in.

I also used Hylomar Blue on the threads of any hose tails fittings and changed all of the copper crush washers for good quality new ones - this resolved the air leak issues that I had.

316 is not suitable for marine applications, try 304 instead, problem with blue hylomar it doesn't set in place, loctite 567.

 

[stevd]

Why isn't 316 suitable? 316 is perfect for marine environment whereas 304 is less so.

Hylomar blue worked very well for me, solved the problem many years ago and the problem hasn't returned - one of its uses is as a non curing thread sealant which is ideal for what I was suggesting.

 

[Gixer]

If you have an air leak try looking at the fibre seal at the top of the fuel filter, as the bleed screw is aluminium, they can draw air, you could replace the bleed screw but use a copper washer.

Thanks B58

The engine will run for about 10mins before shutting down so I guess it must be further back in the system. Also if I run the engine regularly it seems to be ok but when left for a week or two it then does the above.

The current tank is located low down (below engine) on the port side and when full does cause a slight list to port, locker with all the c**p is that side also. I do have a lazarette and have thought about putting a outboard style tank in there before. This is much higher than the engine and I guess would make the engine gravity fed.

 

[ibbo]

Jerry Can Adapter O | Wavian Quality Fuel Cans & Accessories

These are a pretty useful thing if you use jerry cans for fuel any way.

Mike