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Boatguy30 · 10-08-2013, 18:46

Missed a lot of this, but the copper lines were readily available from yanmar dealers a few years ago. Many we're originally steel, but those rusted out so were replaced with copper.m

Teknav · 10-08-2013, 18:48

You should not be using a diesel fuel line made of copper, brass or zinc.

Mauritz

guyfromiowa · 10-08-2013, 19:11

From post #296
The bad news is I have a hole in my external oil line that goes to the rockers and cam.

So I'm going to pull the starter so I can remove the line and see if I can have a section brazed on it.

charliehows · 10-08-2013, 19:33

Quote:

Originally Posted by sailorchic34

Oddly enough the rest of the oil line looks new. Only the section down by the starter was rusting. It was rusting some when I first purchased the boat in 2007. I cleaned it up then and painted it. But it was pretty bad even then.

I'm going to try a copper tube replacement for the one section. First I don't have to get contorted to remove the starter first, which requires I remove the alternator too, as I can change the routing of the oil line a little, and avoid the whole oil line trapped behind the starter thing. I swear Yanmar went to diesel school in Germany. Lets make it complicated.

Plus I can get additional copper tubing for 88 cents a foot, so can keep some on board for field repairs.

On complicated, has anyone tried changing a fuse on a gm series yanmar. They designed it for minimal parts, but complicated so that the case holds the copper clips on the fuse tight to the fuse. Nice in the factory. But they then located it to the side of the engine with short wires, where it will be hard to get at with one hand with the engine installed and it requires two hands to close. Someone needs to take their engineers to a sailboat and have them try to change the #$%^ fuse with the engine in place.

What a lovely piece of engineering and totally unusable on small sailboats. Least wise on mine. Next time yanmar, put the fuse right next to the engine wiring plugs or maybe on the panel side of the engine plugs.

I used copper line to replace/reroute the oil feed to my harley shovelhead rocker boxes a few years ago - now if anything is going to test a material for vibration damage an old harley engine will. Ran for ten years like that 'til i sold the bike - could still be running for all i know.

**roverhi** · 10-08-2013, 19:56

Your problem got to me look at the oil line on my engine. It's rusty. The engine is pretty low hours and very little rust anywhere except that damned line. Wonder if they don't paint the thing. Will try and ospho and paint it in place though it's pretty tight around there. Would have been so much easier when I had the engine out.

I'd be a little leery of a copper oil line. Copper does work hidden easily and crack. That's the reason that it's not used on automobile brake lines. If you see a brake line that looks like copper it's really a cupro-nickel alloy, read monel, that doesn't have the work hardening problems of copper.

**sailorchic34** · 10-08-2013, 21:18

Quote:

Originally Posted by Chas Erwin

Before you commit please consult your metallurgical properties references and ask yourself why no manufacturer uses copper for oil line (nor vehicle brake line either for that matter.)
Charles

While I agree there are some risks with copper. I'm using 3/16" soft copper tubing with a working pressure of 1900 PSI. Yes I will have strain relief and I'm thinking a loop in the tubing for thermal expansion. Just for fun.

Plus I'm soldering the fitting, not brazing. Brazing anneals the copper and makes the joint a failure point. Soldering at 500 degrees does not anneal the copper and preserves the malleability/strength of the copper tube at the joint.

Saw the results of that, gee 20 years ago at the Luxor casino, where the mechanical contractor had brazed the 3/4" copper fittings on the heating loop for the rooms. Faster that way you know... Then they ran the boilers without good or any real temp control and water temp rose to 220-230 degrees (pressure water). They were running the boilers to keep the building warm in winter so the painters could finish up the rooms. Interesting building.

The copper piping expanded floor to floor, which because of the pyramid shape (the piping was running along the exterior slope), was about 15'-16'. The annealed joints failed at oh 1200 places right at the brazed joint. Spec was for solder joints I believe. Exciting!. A great lesson on the issues with annealing copper at brazing temperatures. A combination of "Issues" caused a rather large set of leaks. In finished rooms... with carpet.

Yes copper will work harden over time, if it is subjected to excessive strain/vibration. But the connections are all on the engine and not going off engine. So vibration, torsional strain is less an issue. If I was going from engine to another location, there would be a greater issue with work hardening. I am putting a loop in the piping which will relieve stain at the fittings.

Copper use to be used for fuel and oil lines all the time till the 1940's and shortage of copper due to the war effort. Copper IS less forgiving and can become brittle. I'm thinking / hoping I'm aware enough to adjust the design to make it work reasonably well.

bobconnie · 10-08-2013, 21:21

For a few dollars any good hose shop can make ya a flexable rubber reinforced oil line. That will go where ya want it to with a couple of fitings needed maybe !! Just a thought! Fix once and forget about it for the life of the engine!!

**sailorchic34** · 10-08-2013, 21:25

Quote:

Originally Posted by roverhi

Your problem got to me look at the oil line on my engine. It's rusty. The engine is pretty low hours and very little rust anywhere except that damned line. Wonder if they don't paint the thing.

Oh they painted it. But the paint and some of the metal in the original line flakes off down in front of the starter, and behind the starter too. Above the starter its not a problem. Odd that its just there. The line segments from the head connection around to the cam connections were like new...

**sailorchic34** · 10-08-2013, 21:44

Quote:

Originally Posted by bobconnie

For a few dollars any good hose shop can make ya a flexable rubber reinforced oil line. That will go where ya want it to with a couple of fitings needed maybe !! Just a thought! Fix once and forget about it for the life of the engine!!

That is a thought. Though there are four connections on that line. But only the line from the lower block to the head tee connection has the bad rusting segment. So being a cheap date, I'm trying to salvage the good bits of the piping.

Plus I can reroute the line so I don't have to touch the starter, which is all but inaccessible on my boat. To much stuff in the way. Worried about bits falling into the bilge too. Already lost one crush washer....

If the existing line is rough and not round, the steel line that is remaining is only about 1/2 of the original wall thickness. I cut through the bad section and it was very thin...

RaymondR · 11-08-2013, 02:35

Hi again Sailorchic34,

Just go ahead and use the copper tube without expansion loops or any other complications - the lines are fairly short so there will be very little linear expansion and the bends in the longer bit will take care of the little expansion there is.

Silver solder is what refrigeration repair guys use to solder the copper tubes. It gives a far stronger joint and does not require as much heat as brazing.

lonesoldier0408 · 11-08-2013, 17:48

Has anyone wondered about the location of this rust and the magnetic fields of the starter? I'm no engineer, but the same location on different engines? Did it rust from the inside out? Material in the oil causing this cancer? Heat related to starting attempts with air in the line?

Teknav · 11-08-2013, 18:30

Copper and brass are not recommended as Diesel fuel lines, because Diesel reacts with these metals. Add to that, a very small percentage of water contaminant that exists in Diesel fuel will corrode the thin walled copper tubing. Standard copper tubing used as a fuel line is not thick enough to handle pump pressure and the corrosion; it will break then leak. It is preferred to use stainless lines for Diesel fuel.

Mauritz

Badsanta · 11-08-2013, 18:53

Quote:

Originally Posted by lonesoldier0408

Has anyone wondered about the location of this rust and the magnetic fields of the starter? I'm no engineer, but the same location on different engines? Did it rust from the inside out? Material in the oil causing this cancer? Heat related to starting attempts with air in the line?

Maybe stray current from starter to the engine ground?