Bukh DV 20

[PabloPicasso]

Hi all

My pal is looking at a boat with Bukh DV 20 engine

It seems like on old unit.
What's the generall view of these engines?

Are spares available, etc

Is it a. "replace it, it'll be too much hassle" engine?

We would value informed opinions

Many thanks

 

[LittleSister]

Two recent threads on Bukhs.

Opinions about the Bukh motor please

Bukh DV 10

 

[vyv_cox]

The first thread seems to cover most of it. It is a fiddly engine to work on, many bolts to undo and some odd engineering when you get deep into the engine. As said, very heavy: I replaced ours with a Yanmar 3GM30F that was 100 kg lighter. Spares are very expensive but that is probably true for most marine engines

 

[Wansworth]

Oh dear put me off the boat in Coruna

 

[LittleSister]

Oh dear put me off the boat in Coruna

Why?

It's as good or better then any other older generation engine, and unlike many from that era most spares are readily available (not least because the DV24 and DV36, which share a lot of parts with the DV10 & DV20, are still in production). Unless you are going to up your budget to buy a boat with a modern engine (most based on Asian industrial engines) you are going to have an older generation engine, and it being a Bukh is certainly not a reason not to get it.

 

[Wansworth]

Why?

It's as good or better then any other older generation engine, and unlike many from that era most spares are readily available (not least because the DV24 and DV36, which share a lot of parts with the DV10 & DV20, are still in production). Unless you are going to up your budget to buy a boat with a modern engine (most based on Asian industrial engines) you are going to have an older generation engine, and it being a Bukh is certainly not a reason not to get it.

Thanks for your comments…..another yacht in Coruna has a Volvo engine which sounds like the thing is in bits…..If it doesn’t rain or blow a gale might pop down to Sada and have a look,engines are my nemesis

 

[LittleSister]

Thanks for your comments…..another yacht in Coruna has a Volvo engine which sounds like the thing is in bits…..If it doesn’t rain or blow a gale might pop down to Sada and have a look, engines are my nemesis

I thought they were your saviour? Your go-to excuse for rejecting any boat that wasn't already eliminated because it didn't have wide side decks. If you didn't have that, you might have to buy one!

Yes, engines can be a pain in the posterior (and/or wallet), but despite the impression online resulting from people talking about them only when they've got problems, actually most boat engines work away satisfactorily and reliably the vast majority of the time. So be wary, but not terrified!

If you find an engine that:
- doesn't look a complete mess;
- for which most spares are readily available;
- oil pressure and charge alarms sound properly and warning lights show when switched on before engine running, but go off as soon as engine is started (you might need to blip the 'throttle' a little above tickover to kick the alternator into action), and come on a gain when engine stopped;
- starts easily from cold - this is an important indicator of serious and non-serious problems - if it doesn't is the owner using the correct technique advised in the owner manual (check that online in advance?), has the engine stood unused for a long time (in which case it might well take a few cranking tries for oil to circulate to seal the rings and free up the engine), and there are some old engines (can't remember makes) which are slow to start in cold weather (unlikey to be an issue in your coast's location?), and starts very easily again when hot;
- runs OK at tickover (likely to need a few extra revs and vibrate more for a minute or two before it warms up a bit);
- engine doesn't jump around wildly nor vibration shake your teeth out (i.e. broken/shot mountings);
- runs well to near max revs, ideally including in the water and in gear;
- doesn't produce great clouds of smoke, other than briefly on start-up or when under hard acceleration;
- goes in and out of gear properly;
- doesn't significantly leak oil, water or exhaust;
- alternator produces a charge (shown by indicator light or gauge);
- oil gauge, if fitted, shows reasonable pressure;
- pumps cooling water adequately;
- doesn't sound overheat alarm if left running for a while (likely to take quite a while to get to running temperature if ashore and hence under no load);
- it is not impossible (some inconvenience is the norm!) to access regular service items (fuel and lube filters, seawater impeller, and (if fitted) engine anode and heat exchanger);
then it's probably OK. (Others may be able to advise additional checks, and/or advise in relation to any particular engine model). If it seems OK to you, you may be able to find to a marine engineer who can do another similar check for you, but with the advantage of greater familiarity and knowledge.

Once you've bought one (chance would be a fine thing! ), do a complete basic service a.s.a.p. (change filters, engine and gearbox lube oil, anode, impellor, etc.) and it will all start to seem a lot less scary.

 

[Wansworth]

I thought they were your saviour? Your go-to excuse for rejecting any boat that wasn't already eliminated because it didn't have wide side decks. If you didn't have that, you might have to buy one!

Yes, engines can be a pain in the posterior (and/or wallet), but despite the impression online resulting from people talking about them only when they've got problems, actually most boat engines work away satisfactorily and reliably the vast majority of the time. So be wary, but not terrified!

If you find an engine that:
- doesn't look a complete mess;
- for which most spares are readily available;
- oil pressure and charge alarms sound properly and warning lights show when switched on before engine running, but go off as soon as engine is started (you might need to blip the 'throttle' a little above tickover to kick the alternator into action), and come on a gain when engine stopped;
- starts easily from cold - this is an important indicator of serious and non-serious problems - if it doesn't is the owner using the correct technique advised in the owner manual (check that online in advance?), has the engine stood unused for a long time (in which case it might well take a few cranking tries for oil to circulate to seal the rings and free up the engine), and there are some old engines (can't remember makes) which are slow to start in cold weather (unlikey to be an issue in your coast's location?), and starts very easily again when hot;
- runs OK at tickover (likely to need a few extra revs and vibrate more for a minute or two before it warms up a bit);
- engine doesn't jump around wildly nor vibration shake your teeth out (i.e. broken/shot mountings);
- runs well to near max revs, ideally including in the water and in gear;
- doesn't produce great clouds of smoke, other than briefly on start-up or when under hard acceleration;
- goes in and out of gear properly;
- doesn't significantly leak oil, water or exhaust;
- alternator produces a charge (shown by indicator light or gauge);
- oil gauge, if fitted, shows reasonable pressure;
- pumps cooling water adequately;
- doesn't sound overheat alarm if left running for a while (likely to take quite a while to get to running temperature if ashore and hence under no load);
- it is not impossible (some inconvenience is the norm!) to access regular service items (fuel and lube filters, seawater impeller, and (if fitted) engine anode and heat exchanger);
then it's probably OK. (Others may be able to advise additional checks, and/or advise in relation to any particular engine model). If it seems OK to you, you may be able to find to a marine engineer who can do another similar check for you, but with the advantage of greater familiarity and knowledge.

Once you've bought one (chance would be a fine thing! ), do a complete basic service a.s.a.p. (change filters, engine and gearbox lube oil, anode, impellor, etc.) and it will all start to seem a lot less scary.

Thank you for your missive……if it was summer I would invite you over……but this week it’s gale force winds and rain.!……I guess I don’t want to buy a problem and cash sump but something has to be done….I knew the designer of the cobra and it has good references though the width of its side decks would have to pass the wife’s inspection……the price has dropped recently so keen seller,anyway will keep you informed!

 

[PabloPicasso]

Two recent threads on Bukhs.

Opinions about the Bukh motor please

Bukh DV 10

That's a useful discussion

 

[afterpegassus]

Mine is now 42 and has never missed a beat. I treat it well and it responds in kind.
My previous was a Gardner 6lxb, absolutely indestructible but a bit big for my current engine bay

 

[oldharry]

Having run both Volvo and Bukh twins, I would say Bukh every time. Bukh spares expensive? Look at Volvos spares prices - eye watering! The Volvo ran OK, but needed tinkering from time to time, but never had to touch the Bukh for other than routine maintenance.

Also the Bukh ran much smoother than its Volvo counterpart. Ok different boats so installation may be part of that. Neither are particualrly easy engines to work on, and as mentioned above, the Bukh has some 'interesting' engineering.

 

[Wansworth]

Having run both Volvo and Bukh twins, I would say Bukh every time. Bukh spares expensive? Look at Volvos spares prices - eye watering! The Volvo ran OK, but needed tinkering from time to time, but never had to touch the Bukh for other than routine maintenance.

Also the Bukh ran much smoother than its Volvo counterpart. Ok different boats so installation may be part of that. Neither are particualrly easy engines to work on, and as mentioned above, the Bukh has some 'interesting' engineering.

Thanks

 

[johnphilip]

Hi all

My pal is looking at a boat with Bukh DV 20 engine

It seems like on old unit.
What's the generall view of these engines?

Are spares available, etc

Is it a. "replace it, it'll be too much hassle" engine?

We would value informed opinions

Many thanks

It is a while ago now but we had a Fulmar with a Bukh 20. The engine itself was fine and ran well for the 12 years we shared the boat. The issues were previous additions to the charging system to"improve" battery charging which boiled a battery and mods to the cooling system with an added heat exchanger and calorifier which required a venting of the system every time the engine reached temperature or it would tend to overheat. Without these owner mods I think it would run on for ever.

 

[chriscallender]

The Bukh is robust, a dedicted marine engine rather than a conversion. Definitely an old school design, but that isn't a bad thing at all and the fact that the company has been making them for so long and still exists is testimony to it being decent. I had one on my old boat, the only thing that caused it to miss a beat was air leaks around the primary fuel filter (not down to the engine itself).

As far as potential problems. bcause it is raw water cooled, I've heard the cooling passages can get blocked up over time and might need descaler put through - but I never did this. To be honest, the same thing can happen inside the heat exchanger on a fresh water cooled engine. As I recall it has a cast iron exhaust elbow which will corrode from the inside and eventually leak/crack. I think I replaced it once on mine.

As others have indicated, its a bit of a heavy lump compared with other engines, maybe an extra 100kg a lot of which is in a very heavy flywheel. Since it should be low down in the boat, not really a problem, just think of it as a heavy, but useful, if not very mobile additional crew member.

Certainly I would have no concerns with a Bukh engine that has had a modicum of care in its life. Its one of the better options, with spares readily avaiable (OK - at a price - but that's pretty much the deal with Volvo, Yanmar etc as well). There's a pencil anode that needs to be replaced during servicing, I would expect that is pretty important for its continued survival in hot salty water.

But yeah, as good as anything else, probably one of the best.

Chris

 

[afterpegassus]

The Bukh is robust, a dedicted marine engine rather than a conversion. Definitely an old school design, but that isn't a bad thing at all and the fact that the company has been making them for so long and still exists is testimony to it being decent. I had one on my old boat, the only thing that caused it to miss a beat was air leaks around the primary fuel filter (not down to the engine itself).

As far as potential problems. bcause it is raw water cooled, I've heard the cooling passages can get blocked up over time and might need descaler put through - but I never did this. To be honest, the same thing can happen inside the heat exchanger on a fresh water cooled engine. As I recall it has a cast iron exhaust elbow which will corrode from the inside and eventually leak/crack. I think I replaced it once on mine.

As others have indicated, its a bit of a heavy lump compared with other engines, maybe an extra 100kg a lot of which is in a very heavy flywheel. Since it should be low down in the boat, not really a problem, just think of it as a heavy, but useful, if not very mobile additional crew member.

Certainly I would have no concerns with a Bukh engine that has had a modicum of care in its life. Its one of the better options, with spares readily avaiable (OK - at a price - but that's pretty much the deal with Volvo, Yanmar etc as well). There's a pencil anode that needs to be replaced during servicing, I would expect that is pretty important for its continued survival in hot salty water.

But yeah, as good as anything else, probably one of the best.

Chris

I've never replaced my engine anode because I couldn't get it removed. For engine protection I've always depended on my hull anode.

 

[Tranona]

I've never replaced my engine anode because I couldn't get it removed. For engine protection I've always depended on my hull anode.

A hull anode will do nothing for the engine as it is in a different electrolyte and not "visible" to the internal waterways of the engine.

The engine has an anode in its cooling water jacket to protect metals in the water jacket that have different potential.

Your hull anode is probably wired to your propeller shaft/propeller assembly through the gearbox housing. Its purpose is to prevent dezincification of the propeller.

 

[vyv_cox]

I've never replaced my engine anode because I couldn't get it removed. For engine protection I've always depended on my hull anode.

I have a long ring spanner that I kept specifically to undo the anode bolt. It is in a tricky location and can become very tight.

A hull anode cannot protect an engine.

 

[afterpegassus]

I have a long ring spanner that I kept specifically to undo the anode bolt. It is in a tricky location and can become very tight.

A hull anode cannot protect an engine.

You'll need to explain that to me in wee words .
My shaft anode appears to have looked after my prop perfectly well.
The engine is wired to the hull anode and appears to have suffered no ill effects in the several decades I've owned it.
Given that it's raw water cooled, then isn't it effectively in the required electrolyte?
I was told many years ago by a naval architect that anodising a vessel was a black art .

 

[alan_d]

You'll need to explain that to me in wee words .
My shaft anode appears to have looked after my prop perfectly well.
The engine is wired to the hull anode and appears to have suffered no ill effects in the several decades I've owned it.
Given that it's raw water cooled, then isn't it effectively in the required electrolyte?
I was told many years ago by a naval architect that anodising a vessel was a black art .

An anode needs to "see", i.e. be reasonably close to, what it is protecting, Your shaft anode can't "see" the water passages inside the engine, that's why you have (or should have) an engine anode.

 

[afterpegassus]

An anode needs to "see", i.e. be reasonably close to, what it is protecting, Your shaft anode can't "see" the water passages inside the engine, that's why you have (or should have) an engine anode.

I quite understand and you haven't quite read my post.