Annie Hill wrote:Re the diesel return line.  We got round it in a way that had all the engineers sucking their teeth and shaking their heads, but it worked for 4 years - we T'eed it back into the fuel line by the engine.  (Possibly even on the engine, but my memory fails me here.  It seemed so logical that I paid it scant attention at the time.)  No dount someone less perfectionist than the Oracle ;-} and a lot more clever about engines than I will come up with the solution.  It's really, really important to get things right, but it's even more important to get sailing.

Don't T the return to the supply line. You may get away with it but you may not. The purpose of all that excess fuel is to cool the injector pump. If you T the return in to the supply you feed hot fuel back to the injector pump and it will eventually fail from over heating.

The only possible exception would be some older slow revving diesels which passed very little fuel back to the tank via the return. By older I mean engines dated before 1990 at the earliest. My diesel a 1994 Mitsubishi passes back at least 50% of the fuel and if the engine has been running under load for an hour or more, it's hot enough to burn you.

Just braise a hose tail on if it is a metal tank. If it is plastic, turn your hose tail into a through hull by braising a large washer to it and then use a suitable threaded nut (or anything with the correct thread that will do the job) to hold it in. You can use a buna-n washer or M5200 to seal it, just don't squeeze it all out. 

Slieve McGalliard wrote: 

The idea of ‘T’ing the return into the supply rings an alarm bell in my memory. It’s such a simple solution that you’d think that it would be used all the time, but it’s not! So there must be a reason.

 

I’m sure I read recently that in a modern diesel engine, over 50% of the fuel drawn from the tank was returned to the tank, and if returned to a different tank the fuel range is drastically reduced. Having gone through the injector pump the fuel will be warmer than when in the tank, and when returned to the tank the large volume allows the heat to dissipate. If it is returned directly to the engine it will be compressed again and heated further, and so on until the pump is being fed with hot fuel, which is apparently not a good idea. It may be that older slow revving design could cope with this, but some engines may not. I would suggest enquiring further before planning to follow this course of action.

It’s just a thought, -Cheers, Slieve

                                                                     Stavanger, Thursday

Jeff, I don’t quite share Slieve’s worries about this. First of all, as far as I know, liquids like water or diesel don’t get hot when compressed, much unlike with gases, but if they do, the temperature will drop again as the pressure drops after the injector. The only heating of the return diesel will be from having being in contact with the hot engine block. If 50% of the fuel fed to the injectors returns, then (if the T-solution is used) what will be fed to the injectors will be a 50-50 mix of warm and cold diesel. That doesn’t sound alarming at all to me. In fact, in my world during winters there may be an opposite problem with the cold diesel getting too thick for the injectors so a special winter diesel (with paraffin added) is used. Whatever you go for Jeff; a full return line back to the tank or the T-solution, it would be interesting to hear how warm the return line actually gets.

Cheers and good luck from Arne

PS: As a fresh engineer in a new job, back in 1976 (!) I was a little afraid of diving into problems in fear of screwing up. An old hand put me on the track by saying this to me:

"Don’t worry; the one who has never failed, has never done anything".

 

The idea of ‘T’ing the return into the supply rings an alarm bell in my memory. It’s such a simple solution that you’d think that it would be used all the time, but it’s not! So there must be a reason.

 

I’m sure I read recently that in a modern diesel engine, over 50% of the fuel drawn from the tank was returned to the tank, and if returned to a different tank the fuel range is drastically reduced. Having gone through the injector pump the fuel will be warmer than when in the tank, and when returned to the tank the large volume allows the heat to dissipate. If it is returned directly to the engine it will be compressed again and heated further, and so on until the pump is being fed with hot fuel, which is apparently not a good idea. It may be that older slow revving design could cope with this, but some engines may not. I would suggest enquiring further before planning to follow this course of action.

It’s just a thought, -Cheers, Slieve

Re the diesel return line.  We got round it in a way that had all the engineers sucking their teeth and shaking their heads, but it worked for 4 years - we T'eed it back into the fuel line by the engine.  (Possibly even on the engine, but my memory fails me here.  It seemed so logical that I paid it scant attention at the time.)  No dount someone less perfectionist than the Oracle ;-} and a lot more clever about engines than I will come up with the solution.  It's really, really important to get things right, but it's even more important to get sailing.

Hey, y'all, I decided to start a new thread for this conversation before the webmaster gets back and orders floggings all around. ;->

Arne wrote:

Jeff, the trick is to not take on all projects in one go. If it is possible to get the engine back in business without removing it, then just forget about the tank for now. Just empty it. Then buy an ordinary outboard engine petrol tank and connect that to the engine’s diesel filter intake via a quick-connection (..fit an extra stop valve on each side of the quick connection as this tends to leak a bit...). With this quick fix you have engine enough for the summer and can focus on the rig, and the joy of sailing. Next year or the next after that you may fit a proper diesel tank - after one or two seasons with sailing. BTW, I think your boat will sail fine. Just don’t make the sail too small ;-)(..and flat...)...

Cheers, Arne

Paul wrote: 

Hi Jeff,

I "bin dare 'n done dat" you are in a similar place that I was in 2004. The details differ but in many ways it's the same place. It's a trap, and one that has taken me nearly 8 years to get out of (it's still another 1 or 2 months before I'm completely out but I'm now confident that I will make it).

Eight years of which four of them were essentially just the boat sitting as I had to deal with other commitments or because I was just too tired when I had time and was unable to motivate myself to put on my overalls and get to work. This whole project has just been me, with very little help from anyone else and few cared whether I succeed or failed. I came very close to losing my boat and the possibility of ever sailing on my own boat again. And this, even though I knew and loved the life style as I had been living it since 1989.

In my case, it was an unavoidably large project (if you rip 2/3 rds of the bottom of your boat out, you have a large project on your hands) but my tendency to do everything as right as I possibly could plus the "well while we are here...") mentality which comes very natural to me, led to the taking on of literally hundreds other projects. Each small and insignificant on it's own but they all add up.

What I should have done was be clear about what I wanted to achieve right from the start (which was fix the bottom and convert to junk rig) and stuck to that. Actually, I did not even need to fix the bottom, I was talked into it by others, none of whom did any of the work and those who committed themselves to help, once they realised just how big a project it was, they quickly found reasons to be elsewhere.

Jeff, your situation is similar to where I was. You have a good basic boat that has a few problems but is otherwise in good shape and can be made sailable without to much effort if you can put aside getting everything just perfect before you go sailing. As I understand it, you have just two main issues. An engine/tank issue and a rig issue. I also understand that realistically you are intentionally going to be sailing a lake. Bearing that above in mind and what I have learnt in the hardest possible way (and assuming your goal is to get sailing), if I where you, this is what I'd do.

The engine: It's a small but will do the job. If it's now in good nick (I know you had problems) and it's going to be reliable, pull the engine, pull the tank. Fix the tank properly (I don't believe the West epoxy will do it, the metal needs specific treatment if the treatment is to succeed.) and put it all back. Don't make modifications that are not needed but tidy up the wiring (I believe you said you needed to do this).

If the engine is dubious, forget about it. Get yourself a 9hp Yamaha with remote control, make or have a bracket to put it on. If you need more battery charging capability than the Yamaha can provide, get a solar panel(s) and an MPPT controller for it. You also/or get one of the Honda Inverter gensets.

I don't like outboards as propulsion for a yacht but it's the quickest way to solve the problem right now.

The Junk Rig: You know what you have to do here now. The fastest and most straight forward is the HM sail that I did for you. Every inch of the way has been mapped for you. All you need to do is get 4 odd roles of Odyssey III and start cutting and sewing. The mast you now have and the battens are straight forward.

If you cannot resist the lure of the Fantail type sail, it's a little more complex and the sailmaking will take longer but I'd still use Arne's method to do the camber. Given that you are going to do a lot of your sailing in light winds (at least at first) put a decent amount of camber in. Your hull type needs it.

The above will get you on the water ASAP. Then you will have the leisure to sort the engine (if you still want to) and other things out and make things exactly how you want them. As I understand it, you will bring Seablossem home at the end of each sailing season. That being the case, going forward you can plan projects for each winter, slowly making Seablossem into the boat you want and still have the pleasure of sailing each summer. You will also find, that as you sail, your ideas of what you want to do and need to do will change and what you think to want/need to do now, may not be it.

PS: Arne's suggestion about the outboard tank is also good.

Last modified: 26 Dec 2012 18:57 | Paul Thompson

And Annie wrote:

Hey, Jeff, I'm sorry to hear that.  But we all go through that occasionally.  Most of us are lucky that at least occasionally, or sometimes quite often, we have other boaties around us to exhort and encourage us.  I guess being winter doesn't help.

Re the tank.  Why not disconnect the old one, get a 25 litre outboard motor tank and use that?  Just strap it in somewhere handy.  Forget about the alloy one.  We had that sytem on Badger and it worked perfectly well.

EDIT: I'll leave this as was. I posted as soon as I read that you were regretting your decision Jeff and then read on.  And then saw what Arne had said.  I decided to leave my post because I was astonished to see how we were both thinking so much along the same lines!  It must be something in the genes that makes one approach an issue in a certain way.

Last modified: 26 Dec 2012 19:36 | Annie Hill