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Bukh engines

14K views 33 replies 14 participants last post by  sctpc 
#1 ·
The boat I just bought came with brand new Bukh engine. (Not installed)
Does anybody have experience with these engines? I know that they are used as lifeboat engines and are specifically built for marine use (not marinised automotive)

It is very heavy and appears to be well built.
 
#2 ·
I have some but only very, and I mean very basic experience with small ones. What do you need to know?
All the best,
Robert Gainer
 
#4 ·
They have been very reliable in my limited experience but parts are a problem. It is a current production engine so you can order any parts you need but I don’t think you will find any stocking dealers in the US. By the way you will only get 19 to 20 usable horsepower from that engine and for a heavy boat it might be a tad light in the power department. I don’t have a need for lots of power and my engine is small by popular standards but you are going even smaller in terms of HP per pound of boat.
All the best,
Robert Gainer
 
#6 ·
Is there a recommendation for HP/LBS of boat?

They have been very reliable in my limited experience but parts are a problem. It is a current production engine so you can order any parts you need but I don't think you will find any stocking dealers in the US. By the way you will only get 19 to 20 usable horsepower from that engine and for a heavy boat it might be a tad light in the power department. I don't have a need for lots of power and my engine is small by popular standards but you are going even smaller in terms of HP per pound of boat.
All the best,
Robert Gainer
 
#5 ·
I had the small, single cylinder Buhk (10 hp) in my Laser 28. I really liked the engine, it was reliable and very easy to work on. Most of the parts were reasonably priced, and parts were generally in stock or a few days away and advice was readily available from a local dealer (Davis Craven at Waterway Diesel) and from online Dealers. It did have a few minor oil leak issues, in that it was hard to assemble the waterpump/fuel lift pump assembly without getting leaks. The only other problem that I encountered was that the steel frame that supports the engine and which comes with the saildrive package fatigued and broke dropping the engine into the bilge. I was able to temporarily support the engine, and remove the steel frame. When I got the frame out I felt that it was poorly engineered and so re-engineered it when I had it repaired.

Their saildrive was very nicely engineered as saildrives go, but it could only use a particular model Gori propellor, and I personally would not have another Gori prop on a bet. I found this prop to be pure junk, and Gori to have a antagonistic attitude if you had a problem, providing worse than lousy service for thier products in North American.

Jeff
 
#7 ·
Ive got a 1977 DV20 that came with my Pearson 36. It wasnt installed and still isnt. From what the last owners said, the motor was great and never gave any problems, but the gearbox gave out. If i would find another gearbox, i would put the motor back in my boat. Its got a ZF gearbox. Ive got all the parts to it somewhere.
 
#10 ·
Raven came with a DV24, originally installed 1991. The only real problem I have had with the thing is that it leaked oil out of the main sump. This turned out to be a poorly installed line for draining the oil and although it took some time to track down the problem once we did so it was easily fixed.

We also had a problem with oil coming out the exhaust. It appears that this was caused by excess fuel not lubricating oil. I'm not a mechanical whizz OK , but somehow it was do with fuel pumping through the system on shutdown. It was solved by making sure we always kill donk with engine at idle. With our previous boat shutting down while engine was revving at over idling speed was not a problem. The Bukh apparently doesn't like it. (No I don't mean shutting down engine at 2500 revs. I'm talking about only a few hundred revs over idle.)

Previous boat had a Volvo Penta . Compared to the Volvo the Bukh is quieter but uses a lot more juice than the Volvo. At first this concerned me greatly until I realised that because it is comparatively quiet we use the thing a lot more than on PB.

The other thing I do like about the Bukh is that it's about as big (I think) as you can go and still hand start when necessary.

All in all no serious complaints although I'm told that a three cylinder would be quieter still. ??? To date parts have not been a problem but then Bukh have an official distributor in Oz. I'm told that parts are a problem in SE Asia or Pacific region. No problem in Europe.
 
#16 ·
They are Danish, not Swedish. And due to rotating counterweights they do not vibrate much. I have a new (2004) DV24ME and really love it compared to the Volvo's and Yanmar's I've seen. But I've only owned boats with Volvo's (and no engines) before. One of my friends installs these in rescue boats WW and is VERY proud of the product, which was one of the reasons for me to choose that engine (having your own mechanic is also great :D )
 
#13 ·
Robert...

What am I misunderstanding?

How does one get a figure of 6.8 from the two figures 27.5 and 1.3 ?

My ship weighs 23,000 lbf, and I have about 35 hp (Volvo say). What speed should I expect? The ship is a double-ender... a Union 36.... with a big footprint in the water and a wetted length of 33 ft, apparently.
 
#14 ·
I am sure Robert (as a Naval Architect) can explain this much better than I can (being a Marine Engineer), but I suspect he calculated the hull speed using an equation like:

Hull Speed (kts) = 1.3 to 1.4 X Square Roof of Waterline Length (in feet)

Hull speed in a displacement (non-planing) hull is when the resistance due to wavemaking basically limits further speed increases. Below that speed, the frictional resistance dominates. The very rough rule of 2 Hp per 1000 lbs generally provides sufficient power to get to hull speed plus a little margin.
 
#20 ·
What's you displacement ?

Raven is 34' displaces about 8 tons in the old imperial scale, 7 tonnes metric.

Relatively easily driven hull, fin keel.

Our Bukh DV24 is quite sufficient for our needs. Yeah, maybe I'd go up in size if buying a new one but its basically cool as. No turbo. We run a three bladed fixed prop btw. Would prefer folding but can't be bothered to pay the dosh.
 
#24 ·
Heavy !!

In theory I'm with T34 on this one in that I like to have the smallest engine possible. Saves on weight, saves on fuel (within reason), with luck can be hand started.

Against this are our local conditions. My preferred sailing area is outside the harbour but we are moored a fair way up stream. To sail from our mooring to the heads can be a strain dodging ferries, racing fleets, tankers, liners and morons in stinkers. Was easy 20 years back, now too crowded so we tend to motor until we are in sight of the heads.

Outside, I'd rather potter along at one or two knots than run the engine.
 
#26 ·
In this application torque, as in most sailboats, will be the main issue One thing is engine torque, another and most important is prop-shaft torque, in other words gearbox ratio and what prop it may handle.
The DV24 has a torque of about 55Nm in rpm range 1800-2400 and is delivered with either 2,5 or 3:1 gear box. That will give roughly 137,5 - 165 on the shaft.
If we compare to Yanmar 3YM20 and 3YM30 the figures will be:
3YM20 (21hp) 51Nm in range 2000 - 2600. Gearboxes:2.21,2,62,3,22:1.
121,5 -133,62 - 164.22Nm on prop shaft.
3YM30 (29Hp) 70Nm 2000 - 2500rpm, same gearboxes as above.
154,7 -183,40 - 225,4Nm.
My answer in this case would be if the attaced gearbox is 3:1, install it, You will probably have enough torqe and 'power'.
I have a 3GM Yanmar with a 2.62 gearbox, cruising wheight of 8000 kg (16000lbs) and run a 3-blade Flex-O-Fold prop. Top speed 7knots+, cruising 5kn at 2000rpm, in a Jeanneau SO37 -2002.
 
#29 ·
GBURTON,

Good call. Is that the BV1505? That's a fairly large engine, but it will be nice having 4 cylinders pushing that Westsail. I think you made the right decision, all things considered.

I like what I've learned so far about them while studying these Beta engines. I'd be interested to hear installation and performance reports when you have them.
 
#30 ·
It's the long-serving Kubota motor.
They have been around a while, so there will be plenty of bits around for them that were used for fork-lifts, generators, and so on.
This is so important in the long term, as the engine supplier cannot charge too much for the parts, as others, Volvo being the worst for me, try to.
If Betamarine try that one on, just find the bit that's broken from a fork-lift supplier, or similar.
The exception will be the marinesed bits, but do they fail often? I wonder.
 
#31 ·
I know this is an old Thread but Im very concerned,
I have a Bukh 10hp and yesterday I got caught in a squall on port Phillip bay and tried to run her at 2700rpm and could only get 2200rpm and oil, fuel was coming out the exhaust, its like she has no power. Starts fine, idles but puts out black stuff and I cant get up the revs. suggested adjusting stop solenoid what do you guys recon is it a major problem and should I get a mechanic to look $$$ or be tight and run it till something happens!!! I do prefer option 1 but would like to have an idea first.
 
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