Bukh DV36 Engine - Winterising query

[Michael Siggers]

Hi

 

So a boat I looked at today has a Bukh DV36 engine which sounded so smooth when running.

 

I am a Liveaboard and am wondering would I need to winterise this over, well, Winter? I realise that it has a Raw water cooling system so worried that it'll freeze. Even though it will be winter soon, I'd still be planning on cruising every time I can get away from my Pesky laptop and work 😃

 

Mike

[mrsmelly]

It will depend on if you are going to use it and how its plumbed. Brilliant engines.

[Michael Siggers]

I'd be trying to get out as much as possible, mainly at weekends although not just weekends. The advantage of being freelance. 

 

I work from home, ie from the boat and spend alot of time on laptop in dull Teams meetings.

 

Essentially, what I'm saying is the boat would never be empty and left, and will be used.

 

What do you mean by 'how it's plumbed'?

 

Mike

[ditchcrawler]

If you are going to live aboard are you going to let the boat freeze on the inside in the winter?

[Michael Siggers]

No, not at all.

 

There is a Diesel Fired central heating system and a Multi fuel stove. There is a radiator in the engine compartment too.

 

Mike

[David Mack]

If its raw water cooled there should be some drain taps which allow you to drain the system down (after you have closed the seacock). These may well empty straight into the bilge. You should get in the habit of closing the seacock and opening the drain valves whenever you leave the boat during the winter months. You don't want to find yourself in the position of not bothering because you plan to be back on board in a couple of hours, but something unexpected happens and you end up staying away overnight on the coldest night of the year...

[Tony Brooks]

11 hours ago, Michael Siggers said:

What do you mean by 'how it's plumbed'?

 

I had a nominally direct raw water cooled DV36 but it was connected to a skin tank so no winterisation was needed because of the antifreeze in the coolant. This seems fairly common on canal boats, especially with the hire fleet that used a lot of Bukh engines.

 

DV36s are also supplied as heat exchanger cooled engines that still use antifreeze in the bulk of the cooling system, so the raw water is only in part of the system

 

The question is to try to get you to trace your pipework to establish if it really is direct raw water and not a bit of a mash up, or heat excchanger cooled.

[Michael Siggers]

3 minutes ago, Tony Brooks said:

 

I had a nominally direct raw water cooled DV36 but it was connected to a skin tank so no winterisation was needed because of the antifreeze in the coolant. This seems fairly common on canal boats, especially with the hire fleet that used a lot of Bukh engines.

 

DV36s are also supplied as heat exchanger cooled engines that still use antifreeze in the bulk of the cooling system, so the raw water is only in part of the system

 

The question is to try to get you to trace your pipework to establish if it really is direct raw water and not a bit of a mash up, or heat excchanger cooled.

Ah, thank you Tony.

 

I will try to find out. Will have a better look around the engine bay and get some photos.

 

I know when it was started yesterday, there was burbling in the water surrounding the stern of the boat.

 

Mike

 

 

[Tony Brooks]

6 minutes ago, Michael Siggers said:

Ah, thank you Tony.

 

I will try to find out. Will have a better look around the engine bay and get some photos.

 

I know when it was started yesterday, there was burbling in the water surrounding the stern of the boat.

 

Mike

 

 

 

That sounds like either a submerged exhaust outlet that I would not be keen on for the majority of narrowboats or a wet exhaust.  A wet exhaust boat may well still have antifreeze in the engine if it is equipped with a heat exchanger but the raw water part should really be drained down if leaving the boat for more than an hour or so during the winter.

Edited October 7, 2023 by Tony Brooks

[Michael Siggers]

The exhaust port was well above the water line.

 

Need to get back there to day to look as this could be a deal breaker.

 

Mike

[magnetman]

@J R ALSOP has one of these in his narrow boat. I've seen it spit water out the side before but I think he might have converted it to a skin tank..

 

As said they are excellent true marine engines. 

 

If the boat is lived on I don't think its going to freeze but you never know if unexpected events occur. 

 

 

 

[Tonka]

Where is the engine mounted in the boat ? 

Is it in a traditional engine room which I assume it is because you mentioned a radiator or is it in its own compartment under a semi trad or cruiser stern

[Michael Siggers]

Just now, Tonka said:

Where is the engine mounted in the boat ? 

Is it in a traditional engine room which I assume it is because you mentioned a radiator or is it in its own compartment under a semi trad or cruiser stern

Hi its a Trad stern and the engine is below the boards before the rear exit. The radiator is above the board where you walk.

 

Mike

[J R ALSOP]

30 minutes ago, magnetman said:

@J R ALSOP has one of these in his narrow boat. I've seen it spit water out the side before but I think he might have converted it to a skin tank..

 

As said they are excellent true marine engines. 

 

If the boat is lived on I don't think its going to freeze but you never know if unexpected events occur. 

 

 

 

 

31 minutes ago, magnetman said:

@J R ALSOP has one of these in his narrow boat. I've seen it spit water out the side before but I think he might have converted it to a skin tank..

 

As said they are excellent true marine engines. 

 

If the boat is lived on I don't think its going to freeze but you never know if unexpected events occur. 

 

 

 

I have a Bukh 2G105 a two cylinder long stroke 29 HP water cooled engine, originally it was raw water cooled but got fed up with all the weed and rubbish getting drawn in, so 20 years ago i fitted a skin cooling tank system with anti freeze.

It took about 2 years to stop looking over the side for the water outlet.

All Bukh"s are good engines, I installed lots when I worked for Coles Morton Marine in the 70's.

[Michael Siggers]

Hi

 

So and update after visiting today. I apologise in advance for the photo upload..... 😃

 

Hopefully they make sense.

 

Mike

[Alan de Enfield]

3 minutes ago, Michael Siggers said:

Hi

 

So and update after visiting today. I apologise in advance for the photo upload..... 😃

 

Hopefully they make sense.

 

Mike

 

I cannot see any photos.

 

Edit :

They have now appeared.

Edited October 7, 2023 by Alan de Enfield

[Michael Siggers]

[Michael Siggers]

Final few.

I also spoke with the owner and he stated the only bit connected to the outside water is the Intake at Point A. Adjacent to the isolation valve is the filter which prevents weeds getting in.

 

This seems to feed to a pump which then feeds out to the exhaust at Point D in the photos. This then goes into the white container, (silencer?), at the bottom and then out too the exhaust externally which is above the water line.

 

The other photos, annotated in red, seem to show a filler cap which feeds into a header tank which is connected to the engine. This is not connected to anything externally and the owner told me this is where antifreeze is added. In this cupboard is also a Water Separator.

 

I have also attached a picture of what I think is a Skin Tank with two hoses which are connected to the engine.

 

Anyway, thoughts would be appreciated.

 

Many thanks

 

Mike

11 minutes ago, Alan de Enfield said:

 

I cannot see any photos.

Apologies as I had to resize them.

 

Should be there now.

 

Mike

Forgot to add this one.

 

Mike

[Tony Brooks]

It certainly looks as if it is tank cooled but with a wet exhaust. I would expect the brass pump to supply the wet exhaust, so what is circulating the skin tank water. There should be another pump somewhere.

 

Make sure the raw water does not pass through the exhaust manifold. If it does not, then the only winterisation is ensuring the raw water pump is drained when you leave the boat for a longer winter period. If the manifold is cooled by raw water, then ideally that would be drained as well. The raw water pump will need annual impeller inspections and changing as required. There is also an anode screwed into the block and even with antifreeze these do get eaten away.

 

In severe cold, the silencer and water separator may freeze, but hopefully they will cope with it.

[Michael Siggers]

Thank you @Tony Brooks

 

Very much appreciated.

 

So, I'm thinking that is good news?

 

As part of the sale, the engine is being serviced so I'm going to make sure I'm there for that. The owner was very knowledgeable about the engine as well so that was encouraging. He did state the impeller was renewed at the last service, but again, I'll check its OK.

 

I didn't look for any other pumps as was concentrating on trying to figure out where this pipework was going, so I will check.

 

Mike

[Tony Brooks]

Just now, Michael Siggers said:

Thank you @Tony Brooks

 

Very much appreciated.

 

So, I'm thinking that is good news?

 

As part of the sale, the engine is being serviced so I'm going to make sure I'm there for that. The owner was very knowledgeable about the engine as well so that was encouraging. He did state the impeller was renewed at the last service, but again, I'll check its OK.

 

I didn't look for any other pumps as was concentrating on trying to figure out where this pipework was going, so I will check.

 

Mike

 

I would follow the lower skin tank pipe back to the engine, although not 100% the engine water pump is likely to be where that pipe joins onto the engine.

[David Mack]

13 hours ago, Michael Siggers said:

This seems to feed to a pump which then feeds out to the exhaust at Point D in the photos. This then goes into the white container, (silencer?), at the bottom and then out too the exhaust externally which is above the water line.

The white container in the last picture is a water separator (as it says on the label), so from here there should be separate pipes for the exhaust and the separated water to the outside.

 

There appear to be two separate circulations one around the engine and skin tank, with the header tank, and which should be filled with water/antifreeze mix, and a separate system which takes canal water through the filter and jabsco pump and injects it into the exhaust then separates it again. The jabsco pump is shaft driven from a purpose made drive, rather than being a belt driven add-on, so it appears this engine was always intended to have two circulations. So it is a little surprising that it has a skin tank rather than a heat exchanger in the header tank. There must also be a second water pump somewhere for the engine/skin tank circulation.

[Michael Siggers]

On 08/10/2023 at 11:36, David Mack said:

There must also be a second water pump somewhere for the engine/skin tank circulation.

Hi @David Mack

 

According to the manual, the pump for the skin tank system is on the back of the engine, so I'm going to look for this when I'm next there, on Friday.

 

I'm probably sounding a bit thick, but why is canal water injected into the exhaust system at the point shown? And just to clarify, the top white tank is the water separator, but what is the round white 'tank/container' at the bottom of the boat, which the exhaust goes into before going back up to the outside?

 

Mike

[magnetman]

If you don't add water to an exhaust pipe made with convoluted flexible rubber hose it will catch fire. 

 

 

 

 

The round white box at the bottom is presumably a waterlock type silencer. 

 

 

 

 

With the HMI water separator box presumably this is a dry exhaust outlet or just a tiny bit of water as the water is cleared by gravity in that box and the cooled gas goes out the hose. 

 

Water separators are normally associated with small generators to make them very quiet in operation as it stops the sploshing noise from the exhaust. 

 

Where does the water from the separator box go? 

 

Edited October 11, 2023 by magnetman

[Michael Siggers]

11 minutes ago, magnetman said:

Where does the water from the separator box go?

Not entirely sure. It's bugging me as I really want to check this now but the boat is not out the water for the survey until Friday.

 

When the engine was run there was no visible sign of water coming out the exhaust.

 

Also, been trying to identify the parts in the attached images.

 

I think the part I've labelled Pump is the water pump for the sealed cooling system.

 

Think I've been looking at this so long, I'm confusing myself 😃 Just trying to definitely establish it is a sealed system with Antifreeze.

 

Owner says it is and will be asking the Surveyor on Friday.

 

Mike