Volvo MD3B

[novice04]

Greatings to all forumites from Croatia! Fulfilled my dream this summer and bought a beautifull 30 ft wooden motorsailor. It came with volvo MD3B (1977, but I suspect not more than 500-600hr in action) with it and the previous owner assures me that this engine might last practically forever. The design is simple enough, and the motor in a condition good enough to make me believe it. Any comments? Ups and/or downs for this motor? Spares? There is some thin white smoke during the first hour of running, though - should I be worried?
Another question - noticed that in your parts of the world many wooden boats spend winter on the dry. Here this is not a practice - they say that wood would dry too much???

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[oldharry]

Not a bad engine - but with one major and fatal weakness. The oil pumps wear, and unless checked regularly cause terminal damage to the crankshaft bearings. £350 a set, plus possible damage to the crankshaft, plus £160 for the gaskets to rebuild the engine.(Uk prices include 17.5% VAT) add to that the engine probably having to be lifted out, and the labour and you end up with a hefty repair bill. Also, if the O rings on the oil pick up tube from the sump fail - same expensive end.

Otherwise a pretty good engine. But it is an old one, some spares are no longer available (cranks and oil pumps being particularly difficult to locate!) and as an owner commented recently - being an old engine, Volvo price the spares as valuable antiques!

The thin white smoke may be nothing more than steam, so it is worth checking that the coolant is flowing freely, and the pump is good. Otherwise the injectors might need servicing and re-setting. There might also be a minute air leak in the fuel line between the lift pump and the injector pump. Wipe every joint and connection in the fuel line completely clean and dry. Ru the engine for half an hour, and check the joints again with something like a clean soft tissue. Any trace of oil will mean there is a leak which will be admitting microscopic bubbles to the fuel. not enough to stop the engine, but enough to cause the white smoke you describe. Power will be a little down also if this condition exists.

UK is a notoriously damp place but even here wooden boats can dry out too much, and it is definitely not a good thing to let a wooden boat dry out too much. Shrinkage can actually stretch or distort the fastenings, so that the hull never properly tightens up again, so if local practice is to keep wooden hulls immersed, it would be wise to follow that advice.

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[novice04]

Thanks Harry! Very usefull. Now, if you'd be so kind, what would be your suggestion for future replacement in the range of 35-45 hp. Is there something that could also last another 30 years or so?

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[bedouin]

To echo what has been said. The MD3B is a very reliable engine which can keep going for ever. The white smoke is nothing to worry about.

However having major work done on it could be expensive, so probably recommend keeping it going as long as you can without spending too much, and the replace it should it require any major work.

I don't know any engines being built now that will last as long, or put up with as much mistreatment, but there are lots of advantages with modern engines...

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[novice04]

Thanks Bedouin,
Advantages such as ... ? Just courious.

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[bedouin]

Advantages include: Quieter, Smoother, Lighter, Smaller, Indirect cooling rather than direct cooling...

The MD1/2/3B are best described as agricultural. They are reliable and last forever but no one ever described them as refined /forums/images/icons/smile.gif

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[novice04]

O.K. Bedouine ... I see what you mean! Any recommendations??

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[bedouin]

No - I'm afraid not, My 33 year old Volvo MD2B is still going strong /forums/images/icons/frown.gif - not many other makes of engine would do that.

Many people recommend the Beta as a replacement, but I have no first hand experience.

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[oldharry]

As others comment, modern diesels are quieter, smoother, lighter, etc. as to what will last another 30 years? Well that depends on amount of use/abuse, regualr serrvicing and above all regular oil changes.

But will you want one in 30 years time? The infernal combustion engine may well have been relegated to the scrap heap in favour of some new technology.... or oil may be so scarce (for political as well as green reasons) that its use as a fuel for pleasure boats is no longer viable anyway. If the battery problem is finally solved we may all be running electric motors, or some non fossil fuel power source - like the wind.

Errr... isn't that where we came in?

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