bukh?Why bukh?

[TNLI]

Just love older posts, as they have more time to mature. I visted the local rebuld center for Bukh diesels and the very clued up owner said the main reason they fail is oil contamination is a few cases caused by heat exchanger seal failures causing overheating. Hence the need to buy one with keel cooling. To answer my own question I think it was a 20hp salt cooled job, and I seem to remember that one had a direct drive cooling pump. The seals fail and it's Mayo for oil time!

 

[LittleSister]

PS: I would steer well clear of a direct or salt heat exachanger cooled version, as they were designed for keel closed loop or tank cooling. Not daft suck and spit systems!

I don't think that's correct (leaving aside the delay issue pvb pointed out). I have one of the very earliest Bukh DV36s, and that was supplied new as 'daft suck and spit', and is still raw water cooled and going strong 43 years later.

For most of the production life of the Bukh DV36s they have been available with direct, indirect and closed circuit cooling options. According to Bukh, indirect, rather than direct, cooling is only warranted if the engine is doing more than 500 hours per annum. Closed circuit (e.g. keel-cooled) is, of course, desirable for the particular needs of lifeboats, but impractical for most other vessels.

 

[TNLI]

Ah yes you can buy a new one with a heat exchanger, BUT not for a lifeboat, and that is what they were designed for. I only use lifeboat engines as they can be hand started in minus 40C, IF you use 0 or 5W40 ( Acea B4) engine oil. They are almost bomb proof in comparison with more modern marine diesels.

Keel cooling is not impractical for most engines, but it can cost more, as they do not include the 2 bronze pipes, (I can't use them due to my boats composite alloy hull), so I'm fitting an internal alloy tank that can be diverted to a small radiator in the forward cabin when grounded, or in need of some heat.

 

[LittleSister]

The issue with the Bukh DV10s and DV20s (same thing as the DV10, but with 2 cylinders) is that the raw water pumps were direct driven from the front of the engine, and if the both the pump seals failed and the owner failed to notice the drips from the drain holes specifically provided for the purpose (or these became blocked) water could migrate along the shaft back into the engine and contaminate the oil.

Should be easily avoided by careful maintenance. Replacement of the raw water pump with a belt driven one is not a difficult job for those who remain in fear.

 

[LittleSister]

Ah yes you can buy a new one with a heat exchanger, BUT not for a lifeboat . . .

But no one was discussing lifeboats in this thread.

. . . BUT not for a lifeboat, and that is what they were designed for.

I'm doubtful about that.

p.s. Bukh certainly claimed (and still claim) that the DV36 was designed from the outset as a 'marine' engine, but don't state, even in their advert for lifeboat engines, that it was specifically designed solely as a lifeboat engine. (And I would be unsurprised if it didn't bear some family resemblance to their earlier tractor engines!)

 

[TNLI]

Tractor engines are much tougher than normal marine engines in main block terms. I should have pointed out I'm rebuilding a sunken lifeboat that was fitted with a BMC 1500, (About 40hp absolute max hp at block rather than gearbox output), so it matches the Bukh 36, apart from needing new mounting plates. The original BMC was totally beyond repair, fully siezed due to an ingested glow plug breaking a piston and then on the bottom of the ogin for nearly a year of electrolysis.

 

[Bilgediver]

I'm presently helping a friend rebuild her 20 odd years old Bukh.There was water in the sump wich turned the oil into a gooey mess with the consistency of very thick peanut butter.She had the good sense to stop the thing when she detected a change in note so damage shouldn't be very extensive.The point I'm trying to make here is that this engine is unnecessarily complicated and, of course that reflects on the price.There are counterweights everywhere and also an advance and retard injection timing system.Its weight is astronomical no doubt due to all those extra bits that you don't find in more modern and equally (if not more) reliable designs.

If there was that much wrong with the design and engineering of a Bukh engine then it would not have been one of the few engines in the world that for many years were the only ones certificated by Lloyds and DNV for use on ships lifeboats.

Poor maintenance and setup could be responsible for your problems. I suspect that regular sounding of the sump would have detected water a lot sooner and most people who have these engines know that the first place to look when this happens is the sea water pump and check the weep hole is clear and replace both seals.

The big heavy governor weights which are very similar to old Volvo governor weights do not adjust the timing but like every other diesel engine of that age adjust the volume of fuel delivered per stroke and so power delivered. The timing is preset by the shims under the fuel pump just like Volvo Kubota, Yanmar and many others. Many marine engines have big external flywheels and most Bukhs I have dealt with are very smooth running. Are you sure the counterweights are set up correctly?

Oh.... I nearly forgot. Be careful that if fitting new cap screws to the flywheel you use the CORRECT grade. Fitting the wrong ones can lead to interesting moments when the flywheel goes walkabout in the bilges.

 

[TNLI]

Bukh still make the most reliable marine diesels using their very own blocks, BUT by heck are they heavy. Twice the weight of a Yanmar, and 50% more than my old BMC 1500D. If you need to know how much a new one will cost, it's going to be too much for you !!

So my vote for a reliable new marine engine goes to, (Drum roll), BETA.

 

[jwfrary]

I think there's probobly things that I don't like about every engine,

For example beta wiring looms are pretty rubbish, welded heat exchangers not that durable, but lots of options and different risers available which makes retrofit a dream.

When you realise there's Actully only a handful of engine block in the sub 30hp range, really your buying a kubota, yanmar, mitsubishi, perkins or lombardini.

Buhk operate in a niche sector and if you value the USP they offer which is the large amount of different ans multiple starting methods including the ability to handstart then great.

While 'modern' diesels are light weight they are not as forgiving as the older designs when it comes to failures, and while they are all reletivly simple a heavier engine always has more 'meat' to apply a fix to.

It has to be said though currently I think its less about the engine you would like and more about then one you can actually get ahold of.

The other thing buhk are possibly best at is parts for old engine. Partly as the design has stood the test of time and hasn't had a lot of variations, but 30 year old volvos are difficult for genuine parts, yanmars are OK, but some manifolds are now impossible to get and I'm sure theres other examples, betas parts department are helpful, I haven't needed any 'old parts' though as the engines usually junk and more cost effective to get a new one ordered up....

In summary Im a bit on the fence, a good engine is a well looked after one, that was installed well, in a clean tidy dry engineroom, with good clean fuel and regular oil and coolant changes. Regular injector servicing like we do in the commercial world would fix a lot of the issues people have at the root cause, I only ever see clogged exhaust risers on pleasure boats!

IIl stop before I get ranty

 

[Bilgediver]

Bukh still make the most reliable marine diesels using their very own blocks, BUT by heck are they heavy. Twice the weight of a

So my vote for a reliable new marine engine goes to, (Drum roll), BETA.

These engines started out in life attached to basic motorised farm equipment in Japan . Small ploughs and other impliments that lived in the fields and had to be maintained by the owners. No wonder they operate so well in a cosy engine room!

 

[TNLI]

I think there's probobly things that I don't like about every engine,

For example beta wiring looms are pretty rubbish, welded heat exchangers not that durable, but lots of options and different risers available which makes retrofit a dream.

When you realise there's Actully only a handful of engine block in the sub 30hp range, really your buying a kubota, yanmar, mitsubishi, perkins or lombardini.

Buhk operate in a niche sector and if you value the USP they offer which is the large amount of different ans multiple starting methods including the ability to handstart then great.

While 'modern' diesels are light weight they are not as forgiving as the older designs when it comes to failures, and while they are all reletivly simple a heavier engine always has more 'meat' to apply a fix to.

It has to be said though currently I think its less about the engine you would like and more about then one you can actually get ahold of.

The other thing buhk are possibly best at is parts for old engine. Partly as the design has stood the test of time and hasn't had a lot of variations, but 30 year old volvos are difficult for genuine parts, yanmars are OK, but some manifolds are now impossible to get and I'm sure theres other examples, betas parts department are helpful, I haven't needed any 'old parts' though as the engines usually junk and more cost effective to get a new one ordered up....

In summary Im a bit on the fence, a good engine is a well looked after one, that was installed well, in a clean tidy dry engineroom, with good clean fuel and regular oil and coolant changes. Regular injector servicing like we do in the commercial world would fix a lot of the issues people have at the root cause, I only ever see clogged exhaust risers on pleasure boats!

IIl stop before I get ranty

I've read enough posts on the Beta Farcebook page to know that like many other small diesels, the heat exchanger is prone to corrosion. Luckily I'm rebuilding a lifeboat and their regulations don't allow anything problematic, so it's keel cooling, or keel cooling. Both the RNLI and USCG regs also dictate that there are 2 start batteries that can't be connected to the house one(s), without an isolated cross feed switch, OR hand start and one start battery. Their fuel filter regs are also worth following, although I would have fitted independent tanks and Racor 500FG type units anyway. The expensive regulation for a small offshore lifeboat is the auxillary engine one, so at present I'm looking at a Beta 30 or 38, with a 10kW 48V DC motor with a belt drive on the same shaft. That engine can be powered by a smallish 5kW diesel generator, as the rating is a max 5 minute one. Still a bit short, as it should have a 7.5kw continous rating gen set, and they are real heavy.

There is a 3 month waiting list for most Beta diesel engines in the UK, so I've already asked for their bank details for a keel cooled Beta 30 or 38 with the shallow sump option, as that helps the self righting sums. Not sure which one my CFO will select, as the B38 fits the old BMC 1500 engine beds, but the B30 is way off in both directions. I suspect that when the stealer next visits it will be a tough choice, cos the cost of 4 mounting plates from Beta and some welding will be fairly close to the difference between the 2 engines. Time will tell all.

The best marine engineering company in Poole only deals with Beta or Volvo according to their web site. Perkins are also good, but their dealer is not. The only other option I looked at was a Thornycroft T90, (I think that is a Ford block, if not it's a Mits. one), as Marine Enterprises are only making 2 versions.

 

[Tranona]

The only other option I looked at was a Thornycroft T90, (I think that is a Ford block, if not it's a Mits. one), as Marine Enterprises are only making 2 versions.

Not a Ford derived engine - they don't make anything that small. More likely sourced in China.

 

[TNLI]

Not a Ford derived engine - they don't make anything that small. More likely sourced in China.

Thornycroft have only just gone back into production, they used to make 3 different marine diesels based on the BMC 1500 block, a Mits and a Ford block. The BMC got dropped due to lack of new blocks, but they are now making the other 2 engines that were very popular with RNLI engineers. The Ford block version was in the 37ft Rother, the last of the full displacement offshore boats. I tried to buy an old one in Sweden, but too many issues with the yard and legal ownership. It was also a bit heavy with the HIABB folks saying they would need a 90 ton crane because the local pub only had room at the back. The Rother only weighed 8 tons, but the crane would need a 4 to 1 arm ratio, so max load of 36 tons. The local boat lift folks did have a 40T HIAB, but refused as the figures were too close. Next crane was a monster.

The only UK based marine engine that uses a Chinese block seems to be Canaline. They do make a drop in replacement for the BMC 1500D with keel cooling, BUT there is no way I'm buying an engine with an unproven block.

 

[jwfrary]

I've read enough posts on the Beta Farcebook page to know that like many other small diesels, the heat exchanger is prone to corrosion. Luckily I'm rebuilding a lifeboat and their regulations don't allow anything problematic, so it's keel cooling, or keel cooling. Both the RNLI and USCG regs also dictate that there are 2 start batteries that can't be connected to the house one(s), without an isolated cross feed switch, OR hand start and one start battery. Their fuel filter regs are also worth following, although I would have fitted independent tanks and Racor 500FG type units anyway. The expensive regulation for a small offshore lifeboat is the auxillary engine one, so at present I'm looking at a Beta 30 or 38, with a 10kW 48V DC motor with a belt drive on the same shaft. That engine can be powered by a smallish 5kW diesel generator, as the rating is a max 5 minute one. Still a bit short, as it should have a 7.5kw continous rating gen set, and they are real heavy.

There is a 3 month waiting list for most Beta diesel engines in the UK, so I've already asked for their bank details for a keel cooled Beta 30 or 38 with the shallow sump option, as that helps the self righting sums. Not sure which one my CFO will select, as the B38 fits the old BMC 1500 engine beds, but the B30 is way off in both directions. I suspect that when the stealer next visits it will be a tough choice, cos the cost of 4 mounting plates from Beta and some welding will be fairly close to the difference between the 2 engines. Time will tell all.

The best marine engineering company in Poole only deals with Beta or Volvo according to their web site. Perkins are also good, but their dealer is not. The only other option I looked at was a Thornycroft T90, (I think that is a Ford block, if not it's a Mits. one), as Marine Enterprises are only making 2 versions.

is this the beta marine hybrid ? Or something your cooking up yourself?

keep cooling prob the most realisable way to go, as you say, not practical for most yachts though.

2 batts are one thing, on the buhk you can actually have two starter motors, which is handy if your really wanting to have redundancy. personally I have always liked hydraulic starters, with an accumulator, you can pump that up by hand should it be needed, doesn’t go bad like a battery does. But heavy and takes up a lot of space. Good on the right boat though.

 

[TNLI]

No, the Beta hybrids are a tad too expensive . Keel colling is easy IF the hull is steel, or aluminium like my boat. If not you need to fit external tubes or plates, and that is expensive.
Not heard of a hydraulic starter with a pressure tank used on a small boat. Sounds like a good idea in reliable starting terms.

 

[jwfrary]

No, the Beta hybrids are a tad too expensive . Keel colling is easy IF the hull is steel, or aluminium like my boat. If not you need to fit external tubes or plates, and that is expensive.
Not heard of a hydraulic starter with a pressure tank used on a small boat. Sounds like a good idea in reliable starting terms.

Very common commercially, especially for emergency gensets and on medium speed diesels where electric and air starting is impractical

Famously used on the US coastguard lifeboats with the detroit diesels, spins the motor at about 1000 rpm on them, way faster than any electric starters able to achieve

 

[TNLI]

Very common commercially, especially for emergency gensets and on medium speed diesels where electric and air starting is impractical

Famously used on the US coastguard lifeboats with the detroit diesels, spins the motor at about 1000 rpm on them, way faster than any electric starters able to achieve

Interesting as I used to skipper a 58ft Chris Craft sport fishing boat, and that had a pair of Detroit diesels that had seen near daily use at low power trolling for Marlin and Tuna for over 25 years. No signs of high oil consumption and in real good condition apart from some fouling of the heat exchangers and a few fuel return line leaks as are common on Cooper pipes of real high time diesels. Used to love how the Detroits sound as they wind up to max continous as we burned out the cyliners of Carbon crud each long trip. Garret turbos make a lovely whistle just like a special key on a big church organ. Luckily I didn't pay the fuel bills, as semi displacement boats drink fuel, even at slow trolling speeds, unless we were only doing 2 kts on one engine pulling a live Bonito along at 2kts max, whilst looking for a big Marlin or Mako.

I didn't know the hydraulic starter was heavy enough to use as a auxillary power unit.

 

[peter gibbs]

Re: the water in the sump. It`s worth checking the water pump shaft seals, When these fail water finds it`s way into the engine along the shaft and through the chaincase. Warning signs are water coming out of the tell-tale holes in the pump body. The seals are cheap and easy to replace. There should also be an O-ring between the seals, acting as a thrower. Make sure the tell-tale holes are not obstructed by paint and crud, or by the clamping piece that holds the pump in place.

This is almost certainly the water ingress in this case. No damage is likely. The pump lies off the body of the engine for just this reason and is easily maintained. The whole design is intended for easy access. The build quality is legendary. The weight derives from the thickness of water galleries that do not crumble within a few sesons.
It is not logical to decry lighter build Japanese in boards - the design is the product of many installations. Bukh is different, even over spec for many applications - but never a mistaken choice for small boat propulsion.

PWG
- 10 years experience with Bukh in a Westerly. No commercial connection with the company.

 

[rotrax]

I took a DV20 in bits four years ago after it had seawater in the cylinders. Head and sump off, rods and pistons out, valves and seats refaced, pistons reclaimed - a very tricky job as the rings were corroded into their grooves. I got all the rings out unbroken, cleaned everything up and refitted them. The only new part was a head gasket and two injector nozzles.

Due to Covid I havent seen it for two years but a friend motored it to the boatlift and had it scrubbed and antifouled in March this year so it was working then. It is in Wellington, NZ.

As peter gibbs says, a proper marine engine and as tough as old boots.

 

[oldmanofthehills]

No doubt my 36 year old Bukh 20 would have benef1ted from at least some maintenance in its lightly used life but the 24 Bukh recon replacement still had odd linkage problem to gearbox and throttle. I suspect the lifeboat installed ones get very few sea miles usage unless the parent ship actually sinks - so longevity might be a function of such usage.

I forever bless my Beta 25 that I then got instead. Quiet so the Navigator and myself can hear each other despite age and illness weakened hearing. Starts instantly with no worrying lumbering up to speed. It would be nice to have a hand start but with 3 battery banks I am fairly covered. And it sips fuel to do well under a litre an hour at ambling pace. Right confusing after 500 sea miles and 120 engine hours as we discover that fuel gauge is not lyingly optimistic and the 99euro or pound pump limit is much more than we need at the marinas.