Re-Powering Advice - Page 5 - SailNet Community
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post #41 of 47 Old 12-22-2007 Thread Starter
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Originally Posted by imagstar View Post
2 years ago we rebuilt the md21b on my patents Oyster 39, (in lace w:st="on">Antigualace>) not a bad job as most of the parts were available. The head was a problem and after a ridiculous time surfing the web I found that the basic engine was made by a Renault/Citroen plant and marinized by Volvo. The engine was used in a variety of vehicles, most importantly a citroen delivery van. There are still a lot of these around and in Argentina they make new cast iron cylinder heads, (+ lots of other parts) as I recall $250 and about the same again for shipping. The iron head has advantages over the alloy in a boat
hey, if you are looking for parts for the md21b let me know. currently the entire engine is out of the boat and at my mechanics shop in Jax.

New owner of a Lippincott 30!
Hailing from the West River, MD
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post #42 of 47 Old 12-26-2007
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So whats the up-date?
Did it all fit ? Thinking o f doing the same just not sure of going with a new yanmar or a reco perkins. I truly hope all went well. I always here that the exhaust pipe must be enlarged too, true?
Good luck
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post #43 of 47 Old 12-28-2007
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Watch out for prop size.

I just repowered my C&C 36 Frigate from a Atomic 4 to a 3GM Yanmar I had rebuilt. Went from a 12" prop to a 15" and was recommended at 16". My research with prop manufacturers showed that most boats are under proped and over powered. All you are doing with a bigger engine is spinning water , not pushing the boat. Of course a larger prop meant a larger aperture. All in all I had to cut the aperture out to double opening and reglass; new prop($300); new shaft($400); new seal(PPS $200); new cutlass bearing($20); minor motor rebuild($1150); new control panel($350); new engine beds and purchase used motor($1200). I did all work myself except motor repairs and a friend did that. I've got just under $4500 with materials. All I will advise is check with prop manufacturers before buying bigger engine. I was advised by two manufacturers to rebuild A4 and install larger prop. I had already purchased diesel and started rebuild. A Beta, I believe it was 23 HP, with tranny and control panel was about $7K at Annapolis boatshow. Good luck.
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post #44 of 47 Old 01-23-2008
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Maybe it's too late, but have you thought about electric drive? There are a few companies that will retro fit your diesel with an electric motor run off batteries. No, it actually weighs less than your current engine with a full tank of fuel so the weight considerations are moot. As far as running, expected run time on pure electric is about 7 hours, when sailing you can re-generate via the prop shaft and when needing more, you can install a smaller diesel genset to cover battery charging in a hybrid configuration.

I think it's a smart way to go. VERY seriously considering it myself.

Do a search on Google for solar electric marine drive systems. You will find that you can be completely retrofitted for about the same money and have the advantage of charging your batteries whenever you go sailing.

As most boats (don't know about yours) only use engines to enter and exit marinas, the 7 hour range is quite sufficient. And for us cruisers, a genset is a viable option that will not only make us use less fuel (less emissions and all that good stuff) when we have to, but make us sail more too. Too often we throw on the Iron Genny just because we want to get there faster.

Sailing is about enjoying the journey as much as the destination.

Just a thought.

Stone Age.

the Stone Age

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post #45 of 47 Old 01-29-2008
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I just found this thread, which interests me greatly. I am currently looking for parts for a 1980 Volvo-Penta MD21B. I'm doing a rebuild. I've found that the exhaust pipe/manifold is available new but is like $2500. Anyone have cheaper sources or have one for sale?

Feel free to email me: stephen at
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post #46 of 47 Old 01-29-2008
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That is the problem with Volvo's and I have one myself. Parts if they can be had are to costly. Your $2500 exhaust manifold is 40% the cost of a new Vetus engine. Have you thought about taking the part to a machine shop to have it re-made ? I have done that in the past with a few things and in many cases, it was cheaper.

S/V Scheherazade
I had a dream, I was sailing, I was happy, I was even smiling. Then I looked down and saw that I was on a multi-hull and woke up suddenly in a cold sweat.
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post #47 of 47 Old 01-29-2008
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Ah Sbarker... the famous Volvo exhaust manifold saga, For me it was 1997, and they wanted 1300 for it, $2600, and that was 11 years ago. The motor was an MD17c. Their excuse than was that the motor was old.... 20 years old. Apparently they are not supposed to last that long.

The maniford is cast, and I split mine, and I have never forgiven the V***o b******s for how they tried to rip me off.

I got a second-hand one for 350.

I promised never, never, never to buy another Volvo.

Avoid them you guys out there, or you will learn the same way I did.

They are not too expensive new, but you wait 'till later.

Avoid, avoid, avoid.

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