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Old 13-03-2010, 13:07   #1
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To Repower or Not - Advice, Please

Hello Cruisersforum, I lurk here alot but seldom post, I really enjoy the wealth of knowledge on this site, though.

Here's my dilemma: My boat (1974 Contest 31) is in my back yard for the time being, and my dad is really trying to get me to pull the engine (1989 Volvo 2003) so we can rebuild it. He is confident that we can rebuild it, he's rebuilt many engines in his day... and I'm pretty sure he can fix anything.

Having said that, I am leery to open this can of worms because things in my house have a way of never getting put back together, projects go unfinished, etc. and the space that we would rebuild it in is kind of a mess. In fact, this has been my excuse for telling him that I am not ready to pull the engine for months; I keep telling him to clean up his shop so we have a reasonable place to disassemble it.

I am leaning toward the old adage that if ain't broke, don't fix it. But, that may not be applicable here. This engine may be broke, or at least in the initial stages of kicking the bucket. An oil analysis done last summer says that there are metals present in the oil that indicate "a significant level of cylinder region metals, including pistons, rings, liners, etc.". The report also came back with this recommendation: "This looks like blow-by of unburned fuel that is reducing oil viscosity. I have seen this caused by a faulty injector spraying too much fuel into a cylinder, among other things. Before doing anything dramatic you might check each injector with a pyrometer when the engine is running and see if one is running cooler than the others."

I feel like these comments make sense, and injectors are definitely where I should start. The whole reason that my dad thinks we need to rebuild (besides being generally incapable of leaving mechanical devices intact) is that upon catching exhaust water in a bucket, we found an oil-like slick- which according to the oil analysis, is obviously unburned diesel-right? He and I also would really like to get into the nitty gritty of this engine, as I would like to get hands on experience in diesel maintenance and am interested in seeing how it all works (I have little to no knowledge as it is.)

If a faulty injector is reducing oil viscosity, is this what is causing the levels of "cylinder region" metals to rise? If so, wouldn't fixing the injector problem keep future oil from losing its lubricating properties, and cease further damage to pistons, rings, etc? I know that the wear on those parts won't be reversed, but at least no more harm will be done.

To give a little more information, the engine starts right up on cold days, which in my completely uneducated mind indicates good compression, which means that cylinders are probably not gummed up-is this a false assumption?

Now, the financial considerations... Apparently Volvos are notoriously expensive to rebuild, and I have seen evidence of this while looking (bewildered) at parts lists. I mean, is it even worth it to rebuild a 1989 engine for (probably) several thousand dollars, when I could just buy a new engine, and increase the boat value for if, when I decide to sell?

Part of me thinks that even if we do a complete rebuild, there are still going to be parts that are 20 years old, why not spend an extra few grand and have a new engine? Don't get me wrong though, I'm not rolling in cash- which is why this is such a tough decision. And of course, the other downside to a repower is that I will not have the benefit of tearing the engine apart and learning about it as I would with a rebuild.


Again, boat is 1974 Contest 31' and engine is a 1989 Volvo 2003.

Thanks for any thoughts-what would you do?
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Old 13-03-2010, 13:41   #2
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Parts alone will set you back as much as a new replacement engine. I had a perfectly good Volvo 10, raw water cooled, that had silted up in the cooling passages. Had to take it apart to clear it so did a complete rebuild. I could have bought a new anything for the cost of the parts to put it back together!
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Old 13-03-2010, 13:59   #3
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A good engine mechanic (does not have to be marine, but has to be good) will open the engine in place and check the condition of the head, cylinders, pistons, rings and valves. If there is an obvious damage, he will tell you which parts to replace. If everything is fine there he will just close the engine, start it and tune it for probably as much as a day's work.

Try not to over/worry the issue, unless the engine gives you clear signs of an illness.

b.
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Old 13-03-2010, 14:02   #4
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Think it through

The one difference is that a new engine won't fit exactly.
A recent poster chose to put in a new engine instead of rebuilding.
He spent several thousand just getting everthing to fit. His opinion did a 180.
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Old 13-03-2010, 14:28   #5
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just a thought if you go down the rebuild road, if you can find someone who really knows the engine they can usually point you to other sources of parts supply apart from the brand dealer. Remember all manufacturers have their OEM suppliers, they don't custom design all the parts for an engine. Things like injectors and injector pumps can be rebuilt, new heat exchanger - exhaust manifold assemblies can be fabricated from steel and galvanised, most bearings come from the likes of SKF, piston rings should be able to be matched to another engine.I remember many years ago a mechanic in the know telling us that piston rings for a Ford Falcon (Australia) were the perfect match for our BMW!
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Old 13-03-2010, 15:14   #6
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I agree with Rex. Volvo thinks very highly of their parts and prices them accordingly. Check what it will cost in parts before you start it might be better to replace rather than rebuild. I don't know if it is raw water cooled but if it is I would really think replacement rather than rebuild.
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Old 13-03-2010, 15:38   #7
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Decided to replace my old, gnarly Volvo with a new Kubota. Way smaller, good reputation & power. That was 2 vendors and $25k ago. At least if you're going to repower, do it with someone who you KNOW is able to see the project through. My mistake was, well, never mind, since there were so many.....
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Old 13-03-2010, 16:01   #8
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It sounds like you are toying with 3 options really. Doing nothing, rebuilding, and repowering. The first thing that I would ask is that does the current engine do what you want it to do? If it isn't too loud and has enough power, a good rebuild should come out cheaper in the end unless you hit a big snag.

If you can't justify a repower, the obvious thing to do is to do some diagnosis before going for a full rebuild. Given your description of how the engine starts and runs, it sounds like overall, it is in decent shape. The worrying thing is that you have elevated metal levels in the oil. To me, the best place to start would be with the injectors as you say and see whether the exhaust cleans up. If it does, then you have to figure out whether you want to leave it be or tear into it further. If your boat were in the water, the obvious answer would be to change the oil, run it for a while and get another oil analysis. There are also other tools that might help you decide such as a compression test.

If it were me and the engine was doing its job adequately, I would try to find the cause of the metal in the oil and then make a call from there.
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Old 13-03-2010, 16:05   #9
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Something with parts available readily, especially without the "Marine" tax would be nice.
On the Porsches that I work on, there is often a similar part available made for another car that's 1/2 the Porsche price, especially Bosch injection parts. An engine that is widely used in industrial or farming applications is a seductive idea, but I don't have any first hand knowledge.
I read a repower story (blog?) recently that told of Volvo Marine techs recommending against a Volvo engine. He bought a Yanmar. He was happy with the engine but not at all happy with the installer.
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Old 13-03-2010, 17:14   #10
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Are you getting much blowby out of oil filler cap when removed running? How does the oil pressure look? Do you get an even rpm drop when disabling one cylinder at a time (after injector service). All good indicators of engine condition.
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Old 13-03-2010, 17:59   #11
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To all who replied, thank you for such thoughtful answers.

To Rex and Footloose: Thanks, you confirmed my fear about the parts potentially being cost prohibitive.

I do think that sww914 and marinheiro are right though, cheaper, compatible parts must be out there.

Barnakiel: I think that consulting a good mechanic is definitely a good idea, if nothing else just to perform triage and steer me in the right direction. Unfortunately, the boat and I are now located in inland texas and while mechanics are everywhere, I haven't found a good marine specialist yet. More searching is in order.

Highlander: The fit issue is definitely one thing that makes a rebuild attractive. I think that newer engines are probably more compact though, and I have read that modern diesels are more efficicent, so maybe a slightly smaller engine wouldn't be that much of an issue. If the same bang can be packed into a smaller package, that is. I think that 28 hp is just about the right power for my boat.

Anzo: Thanks for sharing your experience, horror stories like yours definitely don't make me want to repower unless it's really necessary.

Forsail: what would blowby indicate? Oil pressure was consistent when running, I haven't disabled any injectors or done any diagnostics yet. It sounds like you know your engines.

Klem: Thank you for your response, you made it all sound so easy. You're absolutely right about really being faced with 3 options, which just makes my indecision that much more frustrating.
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Old 13-03-2010, 20:54   #12
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Dump it and just put some light weather sails in it's place. Your 13' sweep will double as an emergency spar.
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Old 14-03-2010, 00:34   #13
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How long till resplash?

You don't say how long you plan to have the boat out of service and what your long term plans are.

If you have no major plans for the boat, and are not going to be using it anytime soon why not sell it for what you can get, put the money (and what you'll save) into a sensible investment and go and flip burgers for a hobby. You could end up with enough to buy a newer boat in a few years, or to go chartering sooner.

If you are going to using the boat soon why not just fix what needs to be fixed as soon and as cheaply as possible, put it back in the water and go sailing.

And if you want to do a restoration job on an old classic why not look for one of the old Bukhs, and do the nicest restoration that you can.
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Old 14-03-2010, 00:57   #14
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If your volvo 2003 start straight away from cold, then you could have a problem. Most need the cold start "knack".

We had the head off our 1989 VP 2003 last winter as the head gasket was starting to leak a bit of oil. With new gaskets and a few checks whilst the head was of we now hope to use keep her going for another 5 years. The repower option would have been one of the Beta engines either 25 or 28hp. Howver the direction the propshaft could be a problem so might have needed a new prop and prop shaft if the length needed changing. Fuel consumption would have been the same BTW.

I think you need to borrow a compression tester to see what the readings are and if okay then how about a top end overhaul plus the injectors being checked or refurbished.

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Old 14-03-2010, 04:44   #15
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Blowby is the combustion gasses getting by the rings, A lot of blowby tells that your rings, cylinders and or pistons need attention.

The oil pressure gives you a good idea of how worn your rod and main bearings are holding up. As the oil clearance gets larger the oil pressure falls.

the rpm drop test will show if the engine is performing equally well on all cylinders and can point to valve sealing problems problems with worn camshaft lobes etc .
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