Heavy vibration under power b38 2003

[singlefish]

Im experiencing heavy vibration under power , ive the volve d2-55 coupled to volvo 3 blade folding prop on a 120s saildrive , it has got worse over the years , last year i replaced the prop blades as the teeth were badly worn , previous owner had left in marina on shore power with depleted anodes i strongly suspect .

When i change blades last year the central boss looked ok and blades tight fit .

On cleaning prop this year prior to launch i noticed blades werent as tight a fit .

Vibration was bad from minute boat was launched , i try and find sweet sots in revs , about 1800 , but theres still underlying vibration .


Anyone else had this ?

[Symphony]

Think you have answered your own question. That prop has a reputation for being badly made. The anode erosion and then dezincification of the teeth is due to the poor quality of the alloys used and the small size of the anodes in relation to the bulk of the hub and blades.

[singlefish]

I know why blades had to be replaced , i know anodes dont last , but , would i be wasting time and effort fitting new hub ? , anyone had experience of this ,

Praps i should have bitten bullit last year and fitted different prop all together ?

What have others fitted in place and experience with same .

I liked the volvo prop performance and low drag , but this vibration is a killer .

[Symphony]

I have a FlexoFold. very good, completely trouble free and much better made than the one you have.

[geoff]

I have a kiwi prop on a b40 ocean and am very pleased ,awesome reverse.Geoff

[singlefish]

My thoughts were heading flexfold , but co that sells also make their own prop, featherlight feathering prop , any one experience of them

[Symphony]

Yes. I have one of them on my old wooden boat. Good bit of kit, and probably if it had been available for saildrives when I got the FlexoFold (from the same company, Darglow) I would have gone for that. not really worth changing as my new boat has the bigger engine and the 2 blade does exactly what I expect.

Talk to Chris at Darglow and he will explain the differences.

[singlefish]

So are you using the Two blade flexofold with the 55 hp engine like mine , i thought i would need three blade as i currently have with the volvo folding plop

[philipa]

It may not be the prop.

We had a significant prop wrap a few years ago (B38 / MD2030). Swapped the prop a couple of times, but it didn't help. It turned out to be the vibration damper.

See attached image. You can clearly see the chewed up rubber in the old one on the right.

It was fairly pricy to replace.

- Phil

[Symphony]

So are you using the Two blade flexofold with the 55 hp engine like mine , i thought i would need three blade as i currently have with the volvo folding plop

No. I have a 33 with a D1 30 and previously used the prop on a 37 with a 2030.

Yes, you will need a 3 blade for your engine. The supplier will work out the correct size. Chris has a huge database of boat/engine combinations that he has done so is usually spot on. Yours is a straightforward combination.

[JEN-et-ROSS]

Think you have answered your own question. That prop has a reputation for being badly made. The anode erosion and then dezincification of the teeth is due to the poor quality of the alloys used and the small size of the anodes in relation to the bulk of the hub and blades.

   Interesting observation, we have a 3 bladed Volvo prop that is 27 years old and always behaves faultlessly. Because of it's age we had it inspected 3 years ago by Darglow, it was virtually unaffected by corrosion and therefore deemed suitable to be 'Zero timed'. Should be good for another quarter century !!  (not so sure about it's owner though)

[Symphony]

There are many different versions of the Volvo prop, mostly made by Radice. Not sure about the very old ones like yours, but from the early 2000's there have been problems including replacements under warranty and redesigns, particularly adding bigger anodes to try and keep pace with corrosion.

[singlefish]

It may not be the prop.

We had a significant prop wrap a few years ago (B38 / MD2030). Swapped the prop a couple of times, but it didn't help. It turned out to be the vibration damper.

See attached image. You can clearly see the chewed up rubber in the old one on the right.

It was fairly pricy to replace.



- Phil

I havent had any prop wraps i know of , how did you find out it was vibration damper , take it it lurks in sail drive Somewhere .

[philipa]

how did you find out it was vibration damper , take it it lurks in sail drive Somewhere .

We we're voyaging around Greece at the time. Diagnosis was a process of elimination. The symptoms were similar to those presented by a damaged prop. We first swapped props (with the help of a friendly engineer with the lungs to do this underwater) but the problem persisted. Given the boat-stopping prop wrap, we figured it if it wasn't the prop, it was likely to be the damper. I understand a secondary purpose of the damper is to be sacrificial.

The VD is part of the transmission at the back of the engine, not part of the sail drive. To access it, the engine must be separated from the sail drive. Separation and reassembly is quite a job ? be really sure it's not the prop first.

Our engine is a MD-2030. There was a vibration damper related problem with D2-55's though: http://www.ybw.com/forums/showthread.php?78340-Volvo-D2-55-problem-help-please

[Symphony]

That problem can be usually prevented or at least minimised by fitting a rope cutter. People do not realise how much internal damage can result from picking up debris, which is often sufficient to stop the engine.

This is usually covered by insurance, but to make a successful claim you have to prove that the damage is the direct result of a specific event. This is not always easy as the damage may not be obvious at the time.