Bukh 20hp?

S

scotty123

Well-Known Member
Joined
18 Feb 2007
Messages
6,582
Location
West London
Visit site
What's the life on these engines?
Have seen a few boats from the early 80's with them fitted & they don't look pretty.
Any obvious areas to be aware of for special attention, when viewing?
What is a possible replacement, should it be necessary, particularly if increasing hp (& what cost)?
 
Some people love them and all spares are available to rebuild them. Any of the 20-25hp engines from the major manufacturers are suitable replacements. Budget £6-7k.
 
scotty123 said:
What's the life on these engines?
Click to expand...
My DV24 is around 29 years young and still going fine, I have heard of others much older and still running. I would expect 10,000 hours on the clock to be the limit before some serious fettling was needed.
scotty123 said:
Have seen a few boats from the early 80's with them fitted & they don't look pretty.
Click to expand...
What do you want? Pretty looking or reliable, built like a brick shithouse, hand crankable, long running capability
scotty123 said:
Any obvious areas to be aware of for special attention, when viewing?
Click to expand...
Service history, filters changed regularily, easy starting, rear oil leak between g'box and engine. Other "problems" are minor and easy rectified
scotty123 said:
What is a possible replacement, should it be necessary, particularly if increasing hp (& what cost)?
Click to expand...
DV24 - direct replacement others if you want to spend money for new propshaft, prop, engine beds, exhaust system etc,
 
How do they cope with salt deposits? I was under the impression that raw water cooled engines could die from this?
 
Echo Cliffs post, my V27 was re-engined from a DV20 to a DV24 in 1989, not sure what the problem wautility the original engine but anyway, the DV24 is amazingly reliable and after 23 years there's absolutely nothing causing me any anxieties. I did have a battery problem a couple of years ago (not the engines fault) but was able to fire up the engine using the winder. I just remembered I had to replace the starter motor (£300- ouch!) about 5 years ago but otherwise apart from oil and fuel filter changes, I've not touched it. Great engine!
 
Mavanier said:
How do they cope with salt deposits? I was under the impression that raw water cooled engines could die from this?
Click to expand...

Any raw water cooled engine can accumulate deposits internally but these are quite easily removed using various chemical methods. Many threads on this forum describe the techniques, a search should bring some up. Hydrochloric acid is one, but Rydlyme is often quoted, as is Fernox.

Specifically on a Bukh, the seawater injection nozzle behind the flywheel needs cleaning from time to time.
 
Vyv

What are the symptoms indicating seawater injection nozzle behind the flywheel needs a clean. If I recall ours shows a very light weight crystalline structure growing on the outside of it each year that I wipe away.
Does one simply take the fitting off and poke around removing any deposits, before rebidding with a new gasket.
 
Mavanier said:
How do they cope with salt deposits? I was under the impression that raw water cooled engines could die from this?
Click to expand...

I've heard that, but maybe a different problem.
Have been advised that there are 'tell-tales' on the waterpump, which indicate a water trickle if the front seal goes & these must be kept clear, otherwise the inner seal could go, with seawater in the engine oil side & ruined engine.
 
cliff said:
My DV24 is around 29 years young and still going fine, I have heard of others much older and still running. I would expect 10,000 hours on the clock to be the limit before some serious fettling was needed.
What do you want? Pretty looking or reliable, built like a brick shithouse, hand crankable, long running capability
Service history, filters changed regularily, easy starting, rear oil leak between g'box and engine. Other "problems" are minor and easy rectified
DV24 - direct replacement others if you want to spend money for new propshaft, prop, engine beds, exhaust system etc,
Click to expand...

Whats current cost of one of those?
Is just an extra 4hp worth it, or will bigger sizes also fit ok?
 
scotty123 said:
I've heard that, but maybe a different problem.
Have been advised that there are 'tell-tales' on the waterpump, which indicate a water trickle if the front seal goes & these must be kept clear, otherwise the inner seal could go, with seawater in the engine oil side & ruined engine.
Click to expand...
That is not unique to this engine, nor to seawater cooled engines. Most raw water pumps have seals to keep water from the oil in the engine. The hole is called a witness hole and water coming out indicates the seal on the water side has failed and needs replacing.
 
seumask said:
Vyv

What are the symptoms indicating seawater injection nozzle behind the flywheel needs a clean. If I recall ours shows a very light weight crystalline structure growing on the outside of it each year that I wipe away.
Does one simply take the fitting off and poke around removing any deposits, before rebidding with a new gasket.
Click to expand...

The fitting is quite tightly placed but it can be removed without removing the flywheel. You may need to cut down an Allen key to fit it in. There are two socket headed screws holding the injector. Inside it is like an old-fashioned gas poker, a perforated tube with a closed end. The perforations clog quite readily with salts. If these are not cleaned out occasionally the engine can run hotter, which then increases salt deposition inside. It also increases back-pressure on the pump, that can lead to premature failure of the seal and wear of the shaft.
 
"Vyv

What are the symptoms indicating seawater injection nozzle behind the flywheel needs a clean. "

If the temp alarm goes off and the usual suspects (thermostat, impeller) check out OK, next place to investigate is the water injection. This is what a blocked one looks like (DV10).

inlet.jpg


That's the engine block, behind the flywheel, here's the injection pipe…

rawfeed.jpg
 
scotty123 said:
Whats current cost of one of those?
Is just an extra 4hp worth it, or will bigger sizes also fit ok?
Click to expand...

You will need to be sitting down when you see the price of a new Bukh. Would probably not be first choice for replacement these days as there are plenty of suitable alternatives that are substantially less expensive.
 
My DV10ME was installed in 1982. It still starts easily and doesn't smoke or consume engine oil.

I gave it a major overhaul around 10 years ago and spent about £1200 on new parts, including liner, piston, main and big end bearings etc.
 
You must log in or register to reply here.

Share this page

Top