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Post by Deleted on Feb 26, 2020 20:22:05 GMT
Yes it is smart pipe. New technology is amazing.
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Post by TonyDunkley on Feb 26, 2020 21:03:17 GMT
The fuel pipe that needs renewing is injector leak-off. Run the new one above the steel (high pressure) injector pipe, secured in place with a couple of cable-ties, instead of letting it lay across the exhaust. To fit and run the new one clear of the exhaust you'll probably need it to be about an inch longer than the existing one [determine the exact extra length by disconnecting the filter end of the old one and running it as described], and to slack off and swing the banjo connection to the injector body upwards by a few degrees. . . . . . . . . . . . . . . The new pipe is the same length as the old one and fitted straight away. It would not have worked with a longer length, it would not have bent enough to go over the high pressure pipe.
. . . . . . . . . . . . . . To run a new slightly longer pipe above the steel (high pressure) injector pipe and well clear of the exhaust, all that was necessary was to slacken off and rotate the banjo connection on the injector body a few degrees upwards, . . . which is why, yesterday on page 9 of this thread, I included the following explanation of how to determine the amount by which the new pipe would need to be longer than the old one : The fuel pipe that needs renewing is injector leak-off. Run the new one above the steel (high pressure) injector pipe, secured in place with a couple of cable-ties, instead of letting it lay across the exhaust. To fit and run the new one clear of the exhaust you'll probably need it to be about an inch longer than the existing one [determine the exact extra length by disconnecting the filter end of the old one and running it as described], and to slack off and swing the banjo connection to the injector body upwards by a few degrees.
In what way wasn't that explanation clear enough ?
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Post by Deleted on Feb 26, 2020 21:24:40 GMT
Also, it is quite feasible to re-shape micro-bore pipes without too much difficulty but they normally require annealing first. I've had some really quite pleasing results.
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Post by Deleted on Feb 26, 2020 21:37:28 GMT
"Banjo connection" might be confusing terminology for a lay man.
It's actually quite a good description fo the part bearing in mind it does in fact resemble a very small banjo. A really tiny one.
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Post by TonyDunkley on Feb 26, 2020 21:39:59 GMT
Also, it is quite feasible to re-shape micro-bore pipes without too much difficulty but they normally require annealing first. I've had some really quite pleasing results. That isn't actually what we're talking about here, though, . . the pipe for re-routing was a flexible low pressure - < 5 psi - job carrying injector leak-off to join the tank return from the top of the fuel filter. Micro-bore pipes, or thick-wall HP pipes, such as steel injector pipes, can be re-shaped very nicely after annealing, . . but it's not best practice to do so. The heat from annealing can form internal oxidization scale within the pipe bore which can subsequently break away from the pipe wall in service and find it's way into injector nozzles, . . where it then hangs about and does a lot of no good !
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Post by Deleted on Feb 26, 2020 21:44:14 GMT
Looking at the picture nothing has been done on the fuel system since the paint was applied. I think the engine is a recon unit so probably not original paint. And I guess the reason for failing the fuel return line is that it has not got 7840 stamped on it. Rather than an actual safety reason. It definitely would look better clipped to the high pressure line to the injector as that takes more or less the same route. Bit nasty having it on the exhaust lagging like that.
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Post by TonyDunkley on Feb 26, 2020 22:25:12 GMT
"Banjo connection" might be confusing terminology for a lay man. Asking is always an option !
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Post by Deleted on Feb 26, 2020 22:47:49 GMT
"Banjo connection" might be confusing terminology for a lay man. Asking is always an option ! What would your answer have been? "The red nut on the side of the red bit which looks like a tiny little banjo to left of image after the brown flexible pipe goes into the red metal bits " ?
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Post by duncan on Feb 26, 2020 22:58:56 GMT
The fuel pipe that needs renewing is injector leak-off. Run the new one above the steel (high pressure) injector pipe, secured in place with a couple of cable-ties, instead of letting it lay across the exhaust. To fit and run the new one clear of the exhaust you'll probably need it to be about an inch longer than the existing one [determine the exact extra length by disconnecting the filter end of the old one and running it as described], and to slack off and swing the banjo connection to the injector body upwards by a few degrees. Hi Tony - across the canal, a 15-minute fast walk, is UniMaster who specialise in hydraulic pipes, diesel pipes, etc. The marina owner, old engineer from Bury, Lancs, came to look and tell us what to do, and got me to scurry off to UniMaster to get a new pipe with proper crimps put on. They did it on the spot. The new pipe is the same length as the old one and fitted straight away. It would not have worked with a longer length, it would not have bent enough to go over the high pressure pipe. As it happens, the old pipe was OK!!! When cut open we could then see inside. It just looked frail on the outside. Still, our new pipe is newer, and now it is done. The new pipe has been raised a bit higher from the exhaust by means of 2 cable ties slung around that black water pipe - loosely but firm, not tight-tight. I bought protective spiral sheathing for our cable bundle, took a while to twist it on, happy with result. That was job number 2 knocked off. Then I looked at the starter battery 'spurs' and realised it is easier than I thought, but a job for when it is not raining. I bought a rubber mat and adhesive and we will glue that to the steel wall of the leisure batteries' box. New water pump arrived, job for tomorrow when I am not tired. This 'holiday' has just been running around and I am fair worn out. I look forwards to going back to work and having a rest! Still... we have slept really well on our boat... as usual... why is that? Is it because the boat rocks a bit, or because we get so much fresh air... I would put the rubber mat in place, even if not glued on, before putting a spanner to the battery terminal nuts.
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Post by TonyDunkley on Feb 26, 2020 23:35:46 GMT
I assume the pipe has ISO7840 printed on it. Indeed it does. But what the f is 'marine diesel pipe'? Diesel pipe is diesel pipe, surely? Does our pipe 'know' it is in a boat rather than in a car or bus? It's flexible pipe that meets time standards for fire resistance before rupturing or melting.
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Post by Deleted on Feb 27, 2020 6:59:15 GMT
Also, it is quite feasible to re-shape micro-bore pipes without too much difficulty but they normally require annealing first. I've had some really quite pleasing results. That isn't actually what we're talking about here, though, . . the pipe for re-routing was a flexible low pressure - < 5 psi - job carrying injector leak-off to join the tank return from the top of the fuel filter. Micro-bore pipes, or thick-wall HP pipes, such as steel injector pipes, can be re-shaped very nicely after annealing, . . but it's not best practice to do so. The heat from annealing can form internal oxidization scale within the pipe bore which can subsequently break away from the pipe wall in service and find it's way into injector nozzles, . . where it then hangs about and does a lot of no good ! Its a fair point - I've mostly fecked about with copper water ejection pipes although one or two were steel, and yes, the process of heating them to red-hot did create some oxidisation. What might be done to clean them?
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Post by JohnV on Feb 27, 2020 8:40:14 GMT
To add: Would the angle affect the flow? shouldn't Regarding the fuel flowing back down the return pipe from the tank, I am surprised by that. I am pretty sure all the return pipes on boats that I have owned or worked on extensively either returned to the top of the tank with a swan neck or into the side of the tank high enough to be above the normal "full" level. I don't think I have come across one where it could syphon back ....... I would have thought that extremely bad practise Possibly TonyDunkley or Gazza might comment ?
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Post by Deleted on Feb 27, 2020 9:05:28 GMT
That flexible hose is supposed to be routed around the front of the engine that way it never gets anywhere near the exhaust.
A Google image search for Bukh DV10 will confirm this.
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Post by Deleted on Feb 27, 2020 9:07:58 GMT
As for the fuel system design it probably makes bleeding air out easier.
I had a Russell Newbery once where the fuel return went to the filter not back to the tank. That's bad practice but the engine was fine for the thousands of hours I operated it under load (going along not battery charging).
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Post by Deleted on Feb 27, 2020 9:38:12 GMT
As for the fuel system design it probably makes bleeding air out easier. I had a Russell Newbery once where the fuel return went to the filter not back to the tank. That's bad practice but the engine was fine for the thousands of hours I operated it under load (going along not battery charging). Funnily enough I’ve only just recently had that mod done so the return goes directly into the tank. Apparently you are more likely to end up with an air lock if it’s returned back into the system.
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