Bukh DV20 Exhaust elbow

[Mistroma]

Thank you for sorting all that out!

My thermostat housing bolts just not wanting to budge. They are very solid and I can't see anyway to get diesel down I into the threads.

I will keep trying until the new elbow arrives (hopefully with a new hose - otherwise I will come back to you).

If I am back and running ok with the new elbow and anode then thermostat will rest in peace. I guess the only approach would be to dismantle the exhaust manifold from the side of the engine and get it all to a workshop. Though looking at that now I dont think there is enough space in the engine bay to pull it off the studs sideways!!

At this rate I will be checking in for your head gasket as well!

Avoid removing the head gasket unless you are doing something requiring it. The gasket I have is the one I removed in 1987.

I seem to remember that the manifold is pretty easy to remove and the gaskets are pretty simple in design. I have some material which could easily be cut to make new ones, using the old ones as patterns.

 

[James_Calvert]

I did the same as Poignard on my DV20 some years ago. There wasn't really enough to worry about. Some must have scraped off the liners during extraction.

I did find the anode I'd lost inside.

Talking of which, hopefully Joyfull is aware the anode comes cast onto its own thread, so the small threaded stud pictured in his holder needs removing.

 

[Poignard]

I bought a couple of anodes recently where the threaded stud was about 1mm too long, preventing the anode seating on the holder properly.

Not a big deal if you have a hacksaw or a file on board. If you haven't and you've rowed out to your mooring you might be a bit cross!

I didn't get them from BUKH but from an eBay seller.

 

[rotrax]

Agreed. Any thoughts on a descali

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Reply

I physically poked, prodded and presure flushed the head and cylinder waterways. I knew about the liners so kept them in place with a large washer that covered each liner's edge held down by a length of tube and a head nut. I did not want a liner moveing when I pushed the piston/con rods out. My engine was only blocked around the gasket water transfer holes, easy to clean in my case.

 

[vic008]

Futile expecting any anti-seize to work like that. Really need to make some kind of a dam around each bolt and have a small pool of liquid sitting there with nowhere to go but down the thread. You can use plasticine, or 5min epoxy, whatever.

 

[joyfull]

Futile expecting any anti-seize to work like that. Really need to make some kind of a dam around each bolt and have a small pool of liquid sitting there with nowhere to go but down the thread. You can use plasticine, or 5min epoxy, whatever.

I like that idea. I will see if can create a dam with plastecene and plastic like an old milk container as you suggest around the top of the thermostat housing and then I can leave diesel in the top for several days to get a chance to go down the bolt liners. Certainly worth the effort before I give up on those bolts.

 

[joyfull]

New exhaust elbow just arrived. Will have a refit session at the weekend.

The elbow end of the water hose just has the screw fitting, no compression olive or similar. Is that correct. Just push in hose all the way and tighten?

I am also refitting the anode. Should I grease the thread or anything. Maybe that will just clog up later?

Same for fitting the elbow to the flange. I remember earlier it was said just fit dry after cleaning threads with wire brush.

 

[joyfull]

Typical engine room day. Planned to fit the new elbow and so I thought I would start with an easy job to get into the mood like fitting the new engine anode.

Some chance! Bolt just would not take. I remembered that several people on the forum had mentioned cutting them down to fit, so I check length with a srew driver. More than enough length so tried again, threads still not taking.

Removed anode, tried again and the thread started taking. So I poked around some more and it felt like plenty of room. So tried again with the anode. Still no joy. So I poked around again with the screwdriver. Possibly some narrowing top left hand side inside the block. Could it be that this is deflecting the anodee far enough to stop the threads?

Tried again with and without anode. Same thing. Takes without, wont take with.

So finally decided to try filing the anode down. But anode too hard and file not rough enough. Not sure how much to take off either.

Time to stop for tea and croissant and then head back to find a lathe.

Elbow will have to wait for another day, surely it will go straight on?

P.s forgot to mention in the anode saga I dropped the washer under the engine twice and the bolt once. Definitely not an easy recovery process with much contortion, scrapped knuckles and oily hands and forearms. Ho hum, I am just learning the pleasures of owning old boats with old engines. Not a good idea.

 

[James_Calvert]

Is the new anode is sitting crooked on the bolt and stopping the bolt squaring up to the block to catch its threads?

 

[joyfull]

Is the new anode is sitting crooked on the bolt and stopping the bolt squaring up to the block to catch its threads?

New anode seated square.

 

[James_Calvert]

Is that a Bukh anode or a copy?

 

[Poignard]

You get a build up of crud beyond the anode holder.

I periodically run a tap through to clean it away but failing that you can reduce the diameter of the anode until it goes in.

It shouldn't be difficult to file it as it's zinc. Is your file not sharp or clogged up with the remains of whatever you last used it on?

 

[joyfull]

You get a build up of crud beyond the anode holder.

I periodically run a tap through to clean it away but failing that you can reduce the diameter of the anode until it goes in.

It shouldn't be difficult to file it as it's zinc. Is your file not sharp or clogged up with the remains of whatever you last used it on?

It was sold as bukh anode. I think there is definitely crud beyond the threads. I can feel it is upper left with the screwdriver. Plenty of clearance for length. No reasonable access to get a powertool to it. I guess I will have to reduce diameter towards the outer end with a file.

 

[Poignard]

It was sold as bukh anode. I think there is definitely crud beyond the threads. I can feel it is upper left with the screwdriver. Plenty of clearance for length. No reasonable access to get a powertool to it. I guess I will have to reduce diameter towards the outer end with a file.

Just taper the end until it goes in.

 

[RivalRedwing]

You get a build up of crud beyond the anode holder.

I periodically run a tap through to clean it away but failing that you can reduce the diameter of the anode until it goes in.

It shouldn't be difficult to file it as it's zinc. Is your file not sharp or clogged up with the remains of whatever you last used it on?

Agree I have used a pin punch slightly smaller than the thread to carefully clean out the inside of the head of residue of previous anode.

 

[Champagne Murphy]

The first time I did the anode there was a ‘rim’ of crud just inside the thread. It dislodged with a small screwdriver and the anode went in after that

 

[vic008]

Time to get the crud gone when up and running. Lots of info here on engine flushing.

 

[Mistroma]

It has been MANY years since I had a Bukh DV20 but the anode was replaced annually and that means I must have bought about 24 of these. I seem to remember that the pencil anode had a rounded end, not squared off as in the OP's picture and it was also quite a bit thinner.

I vaguely remember seeing some similar ones in a chandlery and they were longer than the original BUKH ones.

I'll see if I can find any pictures or I noted dimensions anywhere. The OP's anode might just be oversized (longer and thicker).

Might be worth cleaning out the waterways, remember to remove the anode when you get around to doing it.

That's what I did when replacing the thermostat and the only way to get diesel to the threads. I managed to get an amazing amount of crud out of the block and manifold. I used to give it a good hose through and pressure wash every winter. Quite a lot came out of the lower drain with help from bent piece of wire.

I would expect that descaling the manifold would be fairly easy when it is at home and thermostat removed.

You could use citric acid or (80% citric, 20% malic acid) solution, easy enough to buy crystals on eBay. Powerful central heating cleaners are often just citric acid or citric/malic acid. Those sometimes come with an indicator to change colour if more acid is needed or neutraliser for final flush. I've used this mix for central heating and simply flushed until no acid left (test sample with some bicarbonate, no fizz/no acid ).

Sulfamic acid could be used but citric should be fine.

 

[joyfull]

It has been MANY years since I had a Bukh DV20 but the anode was replaced annually and that means I must have bought about 24 of these. I seem to remember that the pencil anode had a rounded end, not squared off as in the OP's picture and it was also quite a bit thinner.

I vaguely remember seeing some similar ones in a chandlery and they were longer than the original BUKH ones.

I'll see if I can find any pictures or I noted dimensions anywhere. The OP's anode might just be oversized (longer and thicker).

Might be worth cleaning out the waterways, remember to remove the anode when you get around to doing it.

Looks the same as bukh anode on Norris website and they only supply oem ( see pix)

 

[joyfull]

Time to get the crud gone when up and running. Lots of info here on engine flushing.

Now where was that info on flushing. Is there a drain plug for access?