Bukh DV20 - Old but good?

[Polarsailor]

Hi All

Just looked at a small open launch fitted with a Bukh DV20. I suspect the engine is original so around 1980. The boat is in good condition and the engine looks like it has been reconditioned well, repainted, lots of new bits including mounts, alternator and stern gear. It started well and ran fine, a bit rattly on the top end but I suspect this was tappets and it quietened down when warm. The engine looks tight with no obvious leaks but it obviously old but I suspect well maintained. The current owner uses a yard for all the work and the previous owner was a marine engineer.

My question is how reliable are these engines? From what I can see spares are still available although the DV20 I believe is now not available. Most of these units have been replaced in yachts but is there anyone who still has one who can provide an opinion? Are they a long term option to keep running if well maintained?

 

[Poignard]

I have a BUKH DV10 built in 1982. Spares are readily available for the DV10 and DV20 but are very expensive. These engines are reliable, long-lasting and not difficult to work on. If the engine does not smoke, has good compression, doesn't leak oil and sounds OK then I would not be deterred by its age from buying the boat.

 

[30boat]

These engines are tough but old fashioned.If yours is working ok ,keep it. Main problem can be waterways corrosion ,normal in raw water cooled engines.
The original water pumps are on the small side but you can upgraded to a larger one if the old one is knackered.Mine which was also from 1980 had no ball bearings and the shaft ran on the brass body.It was a bit worn. These engines have a tendency to steam out of the exhaust and a bigger pump helps to cure that.
There are a few things that can go wrong with these Bukhs. The cylinder liners can corrode through,happened to a friend of mine. On very old engines (around 1980) the camshaft gear may not be pegged to it's shaft and can slip,again happened to this friend of mine and it's not an obvious thing to figure out. Symptoms are lack of power and smoking. And the oil seal bearing surfaces on the crankshaft will corrode and leak.They can be fixed by inserting sleeves.
The heads are prone to warping if overheated. It is important to recut the rings on the head mating surface if it's skimmed.

 

[Minchsailor]

I had an old Volvo in my previous boat. The basics were generally fine but the bits bolted on - alternator, starter motor and even the injector pump - gave trouble.

 

[neilf39]

Mine is a 1980 Bukh. Used it to go to Paimpol and back this year so did about 70 hours motoring with the longest non-stop stint being 18 hours as there was either no wind or it was directly on the nose. Didn't miss a beat. Only issue was a fuel filter leak. Simple rugged engines. It has had a rebuild in its long life.

 

[VicMallows]

My DV20 is a bit newer (1984) and owned since new. The actual engine has required absolutely no attention beyond routine oil/filter change. (Have never even adjusted valve clearance). I have replaced rear oil seal, but only because I had to remove gearbox anyway. Exhaust elbow fails, but latest S/S one has lasted 15 years and still good. Water pump seals last about 5 years but are easy to replace and cost about £2 from an online supplier.

However, every engine is an individual

 

[Champagne Murphy]

Ours is 78 vintage. Re lined with new rings etc a couple of years ago with great success. Needed a good clean but solid as a rock. http://www.ybw.com/forums/showthread.php?337813-Engine-re-spray&highlight=Bukh