Replace a Bukh with a Bukh, or something else?

[Babylon]

Our Bukh DV20 is nearly 30 years old, partly rebuilt in-situ about 12 years ago. Its so far (4yrs ownership) been pretty trouble free, thumpy as Bukhs are, but starts every time and drives the boat well, ie plenty of power for a 27ft long keeler. However this year had some oil leaks which, although solved (front seal, etc), have made me wonder whether its in fact now due a proper complete overhaul/rebuild (can't get to the rear parts etc in situ).

I'm wary of going down the route of spending money on a full rebuild (I'm no mechanic myself) if this - given the age of the engine - proves to be a case of diminishing returns.

The alternative is to replace the engine with something new. Apparently the Bukh DV24 is identical to the DV20 (just modernised to deliver more HP) and will slot directly into place, connect up to the existing hoses, etc, but they are expensive units. My other option would be to fit a new Yanmar or Beta or similar, which would cost less but would involve altering the mounting bed and re-jigging or replacing all the hang-on bits, which would go some way to equalising the comparative costs.

So, have the old engine rebuilt, replace it with another Bukh, or replace it with something else?

Any advice (or opinions) will be much appreciated.

Babs

 

[Boeingdr]

May I ask what the comparative costs of these options are. It is the same set if options I am expecting to face at some time , with a 30 year old presently reliable Bukh 20.

 

[alan_d]

May I ask what the comparative costs of these options are. It is the same set if options I am expecting to face at some time , with a 30 year old presently reliable Bukh 20.

I would be interested in the same information, for the same reasons.

I recall hearing, possibly from a posting on this forum, that the DV24 was not a direct drop-in replacement for the DV20 because of a different gearbox. I hope that is untrue.

 

[PerformanceSailor]

Choices and Options

There are quite a lot of sailors in my region that have switched out various old diesels for new Betamarine's... and they like them a lot.
Considering that these are Kubota short blocks, marinized in the UK, brought back westward to the US, and then shipped across the continent to Oregon... they are still competitive against the Yanmars. Go figure.

I would advise pricing out a Beta, for sure. Speaking of other choices, you guys are also a lot closer to the source for Vetus than we are so perhaps they are a good buy -- Vetus has a lower reputation here, even tho cheaper than other mainstream brands. QC problems with new engines and transmissions...

Personally, I have about 2000 hours on a Universal (marinized Kubota) and it has been very reliable.

About the only one that's only rarely used for a replacement is Volvo, due to their long-established rep. for very overpriced parts.

Good luck in your engine switch.

LB

 

[doug748]

I don't think this is an engineering decision.
To consider changing a good running engine you must be planning to keep the boat 10years +.
If you feel you might feel the need to change the boat in 5 years, or less, then I would consider doing nothing. You like it, it's mended and it could go for the next ten years without attention. If it does let you down badly in the near future, consider a rebuild.
Should you be in it for the long term then an engine upgrade could be worth it (in the next 5 years/when it next breaks down). I could not find a quick price for the Bukh but I would guess £6,000, a useful Beta would be a touch under £4,000 plus all the fussing to put in engine plates. The exhaust is on the wrong side and so are the controls but that is not a huge probelm, given that you may upgrade these anyway. They both spin the same way so you could probably re-cycle your stern gear if it is good. The Bukh is raw water cooled, so at least you could get easy hot water if you fit the Beta (or similar).
So more trouble to fit the Jap engine against probably more cost for the Bukh.
Faced with a similar choice I simply picked the one that everyone else was fitting to my class of boat. Easy.

 

[Babylon]

I don't think this is an engineering decision.
To consider changing a good running engine you must be planning to keep the boat 10years +.
If you feel you might feel the need to change the boat in 5 years, or less, then I would consider doing nothing. You like it, it's mended and it could go for the next ten years without attention. If it does let you down badly in the near future, consider a rebuild.
Should you be in it for the long term then an engine upgrade could be worth it (in the next 5 years/when it next breaks down). I could not find a quick price for the Bukh but I would guess £6,000, a useful Beta would be a touch under £4,000 plus all the fussing to put in engine plates. The exhaust is on the wrong side and so are the controls but that is not a huge probelm, given that you may upgrade these anyway. They both spin the same way so you could probably re-cycle your stern gear if it is good. The Bukh is raw water cooled, so at least you could get easy hot water if you fit the Beta (or similar).
So more trouble to fit the Jap engine against probably more cost for the Bukh.
Faced with a similar choice I simply picked the one that everyone else was fitting to my class of boat. Easy.

Good analysis thank you.

I intend to keep the boat for a while longer (if not for a whole ten years), but the minimum I NEED to do now if I'm not to suffer the continuing oil leaks (and perhaps other internal problems that have potentially built up with a mature engine) over the next few seasons that I suffered this season is to go for a crane-out, get the engine on the engineers' bench and have it properly examined, with a view to a rebuild.

I've now spoken to two marine engineers about my options. The rough costs are as follows:

Crane-out to STRIP & EXAMINE c.£250-300 plus yard cranage. (This will at least give access to the rear seals, etc, which are probably part of the oil-leak problem given that the front seal has already been replaced this year.)

FULL REBUILD OF OWN ENGINE (incl new alternator and other servicable parts) c. £2,000-2,500 depending on what needs doing. (Similar cost if purchase another fully-rebuilt DV20.)

REPLACE with a NEW BUKH DV24 (advantage of minimum messing about with hang-on parts, slightly more power, slightly quieter due to direct-injection) £6,600 plus for engine plus labour!

Replace with a Yanmar, Beta, or similar (24-28HP): with all the messing about to change beds, hang-on bits, prop, etc, cost of engine about £4,000 as you say, but ultimately very close to £6,000 with all the extra fuss, so comparable with fitting a new Bukh above.

My view is to go for the removal and examination (rebuild only if the major mechanical parts need it, else just big clean-up and deal with all seals etc while its on the bench) this winter, which will give me peace of mind over the next few years, and IF I decide to sell in the near future, then this will be a big plus for any potential buyer of the boat.

 

[30boat]

I'd go for the Beta.I say this because that's exactly what I did.My 30 year old Bukh had been rebuilt with new rings and seals but there were still leaks at the crank seals and I had doubts about the internal water galleries.I fitted a BD722 Beta and am delighted with it.
Earlier this year I helped a friend fit a 25HP Beta (same block as the 20)in place of a 20HP Bukh .He ordered the engine feet to match the Bukh ones.The whole thing fitted well but I had to make two small steel fittings to extend the bearers by 5cm.Took me an hour to do.The gearbox ratio was chosen to match the existing prop,more savings there.
The support was first rate.We suspected a faulty lift pump and one was sent immediately by post.

 

[Bosun Higgs]

However this year had some oil leaks which, although solved (front seal, etc), have made me wonder whether its in fact now due a proper complete overhaul/rebuild (can't get to the rear parts etc in situ).

You are solving a problem that you dont have - the engine works! A worn engine will show in areas like oil consumption, smoke out of the exhaust or difficulty in starting due to poor compression. You havent mentioned either of these so to my mind you keep your money in your pocket.

The Bukh is an old style engine. Its lumpy / rough by modern standards but its also infinitely repairable by modern standards. So unless you need to re-engine foir things like fresh water cooling, I would keep on going.

 

[Colvic Watson]

Looked after, that Bukh will comfortably last another 30 years. There will be the odd oil leak but a drip tray will help a lot with the consequences of those. What it won't give you is the satisfaction and piece of mind that a new engine gives. There is probably no more reliable engine than the one you have fitted but I know from having one, that an oil leak does unsettle and I nearly fitted a new Beta after 3 leaks. Once I realised that I knew now what the worst would be (oil leak) I saved the £5k and kept going. Just one thought - have you had the oil breather pipe removed and cleaned? They are an absolute pain to remove - needs masses or torque on the wrench but Bukh say a clogged breather is the biggest cause of oil leaks as the pressure gets way too high. It's a job you can do in situ though. Best of luck with the decision.

 

[Babylon]

Thanks for the useful feedback

You are solving a problem that you dont have - the engine works! A worn engine will show in areas like oil consumption, smoke out of the exhaust or difficulty in starting due to poor compression. You havent mentioned either of these so to my mind you keep your money in your pocket.

The Bukh is an old style engine. Its lumpy / rough by modern standards but its also infinitely repairable by modern standards. So unless you need to re-engine foir things like fresh water cooling, I would keep on going.

Agree. But I did mention oil-leaking as a serious problem. Over three days motorsailing an average of 9 hours a day to windward from the Solent to Brixham I was topping up from the bottom to the top of the dipstick mark every morning before setting off, with a load of oil constantly in the engine bilge (which in the chop spilled forward into the shallow bilge under the cabin sole coating the flexible water tanks, which now need replacing as the oil vapours have penetrated the plastic and effected the water itself!).

Had the engine checked in Brixham and the worn front seal replaced, solving most of the current issue, but there's still a residual problem, possibly from parts and seals less accessible than the front (space to tight to deal with in situ).

Looked after, that Bukh will comfortably last another 30 years. There will be the odd oil leak but a drip tray will help a lot with the consequences of those. What it won't give you is the satisfaction and piece of mind that a new engine gives. There is probably no more reliable engine than the one you have fitted but I know from having one, that an oil leak does unsettle and I nearly fitted a new Beta after 3 leaks. Once I realised that I knew now what the worst would be (oil leak) I saved the £5k and kept going.

Just one thought - have you had the oil breather pipe removed and cleaned? They are an absolute pain to remove - needs masses or torque on the wrench but Bukh say a clogged breather is the biggest cause of oil leaks as the pressure gets way too high. It's a job you can do in situ though. Best of luck with the decision.

One of the engineers I've spoken to suggested this amongst other reasons why we could be suffering from too high an oil pressure, hence my decision to have the engine out and and onto a workbench to be fully checked over, with a view to a rebuild only if needed. This approach keeps my initial costs to a minimum (£300), and a proper rebuild if needed (after 30yrs of service) is no bad thing and not overly expensive (£2,500) for peace of mind over the next few years compared to a new engine.

 

[Bosun Higgs]

Agree. But I did mention oil-leaking as a serious problem. Over three days motorsailing an average of 9 hours a day to windward from the Solent to Brixham I was topping up from the bottom to the top of the dipstick mark every morning before setting off, with a load of oil constantly in the engine bilge (which in the chop spilled forward into the shallow bilge under the cabin sole coating the flexible water tanks, which now need replacing as the oil vapours have penetrated the plastic and effected the water itself!).

Had the engine checked in Brixham and the worn front seal replaced, solving most of the current issue, but there's still a residual problem, possibly from parts and seals less accessible than the front (space to tight to deal with in situ).

Just had to do exactly the same thing for the same reason on a Volvo 2030 , except in my case it was the seal between the engine and the box. You need to look on such seals as consumeables albeit over 15 years rather than 12 months.

I think you are taking the right course. I'm not a Bukh owner / enthusiast, but I have been through the pain of engine replacement and it is never a simple or easy job. It can be much cheaper to do up an old engine provided it already gives you what you want from an engine and provided corrosion of major components isnt an issue. With a Bukh you even have the advantage of removeable cylinder liners so no messing around with re-bores.

 

[prv]

Crane-out to STRIP & EXAMINE c.£250-300 plus yard cranage.

How much of that is the extraction and refitting, vs the actual stripdown and opinion? It's not all that hard to lift out and replace an engine, as I discovered on KS last winter (and her engine bay is *very* restrictive having been re-engined with double the power). I'm happy to pay for expert work I can't do (like assessing diesel engines) but don't like paying professional rates for manual labour.

Pete

 

[black_sheep]

We replaced our 26 year old bukh dv10 this year after fighting with low compression, oil leaks etc. We put in a beta 16 and it is amazing the difference. The boat has a new lease of life, and we are confident that when we go out to her that the engine will start, as well as going backwards and forwards reliably. We got to the stage of myself turning the engine over on the key and my husband using the starting handle, as the starter motor was not enough on it's own. Not being mechanically able to rebuild the engine ourselves, we decided to employ somebody to replace the whole back end. It cost about £6500 to replace the engine, engine bearers, prop and shaft, stern gland, hoses, cockpit drains etc, but having spent the money, we won't be buying another boat for a long while.

 

[Scomber]

same here-just had the first season with a beta 25 after removing bukh dv20 from our 28'6" -30 yr old boat -also replaced all exhaust / new prop / shaft/ throttle /wiring loom etc
we ran the boat for previous 5 yrs always replacing bits and sometimes wondering if it would start / run
took the view that when something major/away from home needed doing then we'd replace-which went well and was completed over a winter
got a few hundred for the old engine and sold off other parts which helped
we intend to keep the boat at least another 5 yrs and even then i hope the new engine will make it an attractive buy if we sell
so at the time it was right for us and the feeling of reliability well!!! worth every penny!!
if you go for the adjustable foot mounts it would make fitting easier

 

[alan_d]

I've now spoken to two marine engineers about my options. The rough costs are as follows:
[Details snipped]
My view is to go for the removal and examination (rebuild only if the major mechanical parts need it, else just big clean-up and deal with all seals etc while its on the bench) this winter, which will give me peace of mind over the next few years, and IF I decide to sell in the near future, then this will be a big plus for any potential buyer of the boat.

Thanks for providing the costings - I hope I shall not need the information in the short term.

Your choice to go for removal and inspection is the one I would have made in the circumstances. Good luck!

 

[vyv_cox]

I replaced a Bukh 20 with a Yanmar 27 about eight years ago. The replacement was considerably lighter, 100 kg IIRC, so much smaller that I could fit a reasonable toolbox in the space previously occupied by the cylinder head. The replacement was straightforward, engine mountings raised one inch, larger exhaust pipe and water inlet up a size. In service it is much smoother and as expected more powerful. A vast improvement on the Bukh. I retained the same shaft and prop for a time, reasonably successful until I fitted an Autoprop instead.

 

[richardsn9]

I don't think this is an engineering decision.
To consider changing a good running engine you must be planning to keep the boat 10years +.
If you feel you might feel the need to change the boat in 5 years, or less, then I would consider doing nothing. You like it, it's mended and it could go for the next ten years without attention. If it does let you down badly in the near future, consider a rebuild.


However, you do need to look ahead at a possible sale of the boat. I kept my old VP going with lots of tlc, blood, sweat and tears. When I finally came to sell the boat it was still running absolutely fine, but as it was considered too old, it became a major obstacle to the sale, and I eventually had to concede most of the cost of a new engine. I should have changed it before, and then at least I would have had the benefit of running a new engine for a few years.

 

[RivalRedwing]

Well I've gone the other way, albeit by accident. My old boat had a Nanni 21HP, professionally fitted in 2001, started reliably and compact (as others have said). I now have a boat with a new DV24, installed by the previous owner in 2009 (replacing a DV20). It is a different style / design of engine but what I really notice is the additional low-down torque and drive through the water that it gives which the Nanni never had. It is probably down to the prop but, if in both cases the prop was correctly matched to the engine characteristics, then the Bukh wins hands down. Many of the comparisons being made are old, tired Bukhs vs new replacements; if yours is still performing to your satisfaction then I would argue that a haul-out and re-fettle of the seals is all that you need do (do the gearbox shaft seals at the same time). Worse case is that the engineer tells you that the engine is barely worth working on and you have lost a few £100, not chicken feed but a lot less than a new engine which you may not need.

 

[SimonJ]

To replace a BUKH?

I quite understand your dilemma!
I rebuilt mine with new liners, new crankshaft seals, main bearings, refurbished/tested injectors & fuel pump, new water pump 8 years ago when faced with the same kind of problem. It cost about half the cost of a replacement just for spares. Since then I have motored rather a lot (several thousand hours including to Great lakes and return from Caribbean & motoring in no wind half way across Atlantic etc). Now I have the aft crank shaft seal leak back, not too significant yet, and starting it is not quite so good. The problems I have to deal with are broken valve springs (due to salt water ingress on occasions - lots of reasons for that with a BUKH!), worn water pump/starter shaft bearings, sheared engine mount bolts (after picking up a net) and clogged water passages. The cylinder head also needed some work. Various poking around and acid cleanings sorted the passages out. Often forgotten are the water passages to thermostat and also the injection bend where water goes in.
BUKH is a great engine and worth persevering with if it is good in your boat. Any possibility of doing the aft seal on your saloon floor while suitably protected? I can get mine there in a couple of hours with no outside help.
Any other engine is likely to be much lighter, this could be good or bad for you! With a different engine you can get more power which you might welcome. A new engine is very likely to need an expensive new prop shaft and a new propellor (and all the tribulations which go with that) plus mount changes. You could slip in a new BUKH without any of that fuss & expense very quickly.
If I was you I would do nothing apart from routine servicing, cleaning the air breather and waterways - until a crisis occurs. PBO did a good article years ago on BUKH (& other engines). I am not quite sure what your mechanic will learn from a bench inspection unless he has done lots of checks while it runs - although I admit a bench test is not too difficult.

 

[Poignard]

However, you do need to look ahead at a possible sale of the boat. I kept my old VP going with lots of tlc, blood, sweat and tears. When I finally came to sell the boat it was still running absolutely fine, but as it was considered too old, it became a major obstacle to the sale, and I eventually had to concede most of the cost of a new engine. I should have changed it before, and then at least I would have had the benefit of running a new engine for a few years.

I think that's a very good point. Few potential buyers are likely to be engineers and will be very wary of an old engine, especially when their surveyor points out its age.