Volvo D2-55 Continuing cooling saga

[asteven221]

I have posted this before and tried to find it so I could continue rather than go over old ground. Unfortunately I can't find the thread!

So the issue is that the engine performs fine and does not overheat, but emits smoke - or more likely steam.

So far I have done a number of things such as replaced the exhaust elbow, replaced the hoses from the seacock to the water pump and recently changed the volvo
strainer to a vetus strainer. I have what I reckon is plenty water coming through the saildrive leg.

Now that i have a strainer I can see through the lid and hoses that are clear I can observe the water flow and it looks odd to me. Maybe it's normal so I would appreciate anyone's comments on normal or not.

What I noticed is that there is what looks like a solid flow of water from the seacock, but the volume of water in the strainer seems low. The outlet hose from the strainer has a lot of turbulence.

I was expecting the strainer to be pretty full of water.

The engine is doing about 1800rpm during the videos. Temperatures are around 35c on the exhaust elbow, Circa 78c on most of the hot surfaces of the engine with an increase in the sump where it goes to the high 80's if I recall correctly.

I will try and post some video.

Thanks a lot for any assistance as this is a very annoying problem, although not so far stopping me using the boat.

 

[pvb]

What I noticed is that there is what looks like a solid flow of water from the seacock, but the volume of water in the strainer seems low. The outlet hose from the strainer has a lot of turbulence.

I was expecting the strainer to be pretty full of water.

It looks like there's air in the outlet hose; did you grease the O-ring on the lid?

With that design of Vetus strainer, the strainer probably won't fill with water unless you force it to (by closing the inlet seacock and pouring water into the strainer).

 

[emandvee44]

We have exactly the same arrangement. D2-55 and the Vetus strainer. We have also had the same problem, i.e. steam emitting from the exhaust. From your videos I can see a poor water flow through the strainer, due either to an inadequate seal at the strainer lid, or a partial blockage on the inlet side or a combination of both. The exhaust outlet is showing a poor flow.We had marine growth ( jelly like stuff) in the inlet hose from the sail drive, cured by disconnecting the inlet hose to the strainer, connecting marina fresh water supply and flushing through for an hour or so at full pressure, which clearsd it . As others have said, a good seal is essential at the Vetus lid as the jabsco pump is pulling a partial vacuum and any leaks in the system will reduce the water flow . Likewise the hose connections must be tight.
M.

 

[DJE]

Looks like a very poor flow. Have you checked the impeller in the sea water pump? There's a lot of air going down there and they don't like running dry.

 

[tillergirl]

Whenever I had steam on my Volvo 2030 it was always a partial blockage at the skin fitting - weed. The suction from the pump was very powerful so continued to get enough water in not to overheat the engine but raised the temperature to cause steam. I was fortunate to have an old fashioned sea cock not one of those remote strainers. I could just take the top off the combined strainer/seacock and rod it. Indeed on a couple of occasions all I need to do was to stop the engine and let the suction go and the tide would clear the weed - very lucky that I admit.

 

[asteven221]

Thanks for all your comments. The thing that I was unsure of is whether or not the flow of water going through the strainer looked right or not. I guess the consensus is no, so I will focus on that. Thanks.

 

[DJE]

When we bought ours she had been sitting in a marina for four years and there were large mussels living inside the saildrive leg. The problem was obvious because the hose from the seacock to the strainer was being squashed by the suction from the sea water pump. That was pretty extreme but blockages in the leg are not uncommon. You could try putting a hose from a tap onto the seacock and back-flushing the leg.

 

[Beneteau381]

Thanks for all your comments. The thing that I was unsure of is whether or not the flow of water going through the strainer looked right or not. I guess the consensus is no, so I will focus on that. Thanks.

Thats not right, the strainer should be full. I can always tell when mine isnt sealing properly, I can see the bubbles coming from the O ring. My money now though is on the inlet in the leg being partially blocked. Listen to mike emandvee, he has had experiences with these.

 

[pvb]

Thats not right, the strainer should be full.

As I said in post 2, that design of Vetus strainer won't fill on its own. There are two almost identical Vetus strainer designs; the OP has the FTR330 which has the inlet pipe only just coming in to the bottom of the strainer basket. The alternative design is the FTR140, which has the inlet pipe rising to the top of the strainer basket - this type is better in my opinion as the water in the strainer won't drain out through the seacock when the engine is turned off, helping to prime the pump when the engine is restarted. These cutaway drawings from the Vetus site show the different inlet pipes.

 

[Beneteau381]

As I said in post 2, that design of Vetus strainer won't fill on its own. There are two almost identical Vetus strainer designs; the OP has the FTR330 which has the inlet pipe only just coming in to the bottom of the strainer basket. The alternative design is the FTR140, which has the inlet pipe rising to the top of the strainer basket - this type is better in my opinion as the water in the strainer won't drain out through the seacock when the engine is turned off, helping to prime the pump when the engine is restarted. These cutaway drawings from the Vetus site show the different inlet pipes.

View attachment 95028View attachment 95029

When running.

 

[RichardS]

As I said in post 2, that design of Vetus strainer won't fill on its own. There are two almost identical Vetus strainer designs; the OP has the FTR330 which has the inlet pipe only just coming in to the bottom of the strainer basket. The alternative design is the FTR140, which has the inlet pipe rising to the top of the strainer basket - this type is better in my opinion as the water in the strainer won't drain out through the seacock when the engine is turned off, helping to prime the pump when the engine is restarted. These cutaway drawings from the Vetus site show the different inlet pipes.

View attachment 95028View attachment 95029

You're right PVB. When I saw the video I thought that it was the same as my Vetus strainer but closer viewing revealed that the inlet pipe is very low in the container rather than right at the top like mine so it was clear that the OP's design of strainer will never be full like mine.

It seems a bit odd that a large volume of strainer seems to being completely wasted and is not doing anything useful, unlike mine, but it is what it is.

Richard

 

[pvb]

You're right PVB. When I saw the video I thought that it was the same as my Vetus strainer but closer viewing revealed that the exit pipe is very low in the container rather than right at the top like mine so it was clear that the OP's design of strainer will never be full like mine.

It seems a bit odd that a large volume of strainer seems to being completely wasted and is not doing anything useful, unlike mine, but it is what it is.

Agreed. The odd thing is that the OP's strainer is listed at £99, whereas the alternative design with the inlet pipe going up to the top is only £80. They both have the same throughput ability.

 

[mjcoon]

Agreed. The odd thing is that the OP's strainer is listed at £99, whereas the alternative design with the inlet pipe going up to the top is only £80. They both have the same throughput ability.

Except that RichardS's version swaps "inlet" for "exit" which is not what you wrote! But you were discussing priming and not filling so are you really agreeing?

 

[pvb]

Except that RichardS's version swaps "inlet" for "exit" which is not what you wrote! But you were discussing priming and not filling so are you really agreeing?

Well spotted, perhaps his strainer is wrongly plumbed? The arrows in the diagrams in post 9 clearly show the correct flow pattern.

 

[Beneteau381]

You're right PVB. When I saw the video I thought that it was the same as my Vetus strainer but closer viewing revealed that the exit pipe is very low in the container rather than right at the top like mine so it was clear that the OP's design of strainer will never be full like mine.

It seems a bit odd that a large volume of strainer seems to being completely wasted and is not doing anything useful, unlike mine, but it is what it is.

Richard

When that system is working properly I would bet you that that strainer is full!

 

[DJE]

The two strainers in post#9 are different sizes as well as different pipe layouts. So that might explain the price difference.

The one I have has inlet and outlet pipes both short but the engine purges the air out of it quite quickly and then it stays full of water unless I take the lid off with the seacock open. If the air can't get in the water won't drain out.

 

[RichardS]

Except that RichardS's version swaps "inlet" for "exit" which is not what you wrote! But you were discussing priming and not filling so are you really agreeing?

Yes, I meant inlet. My mis-speak.

However, we are talking about the filling of the strainer.

Richard

 

[RichardS]

When that system is working properly I would bet you that that strainer is full!

I'm not sure how it could be full as the rate of water ingress will always equal the rate of egress. Even if you were to fill it by hand, the water would always have run down into the sea by the time you get the top screwed on tight. If it were level with or below sea level the it would be full but I don't believe that to be the normal placement.

Richard

 

[pvb]

The two strainers in post#9 are different sizes as well as different pipe layouts. So that might explain the price difference.

Slightly different physical sizes, but both are designed for 19mm pipes, and both are designed for 51 litres/min flow rate.

Vetus Raw Water Strainer Type 140 Inlet Ø 19mm (Vetus FTR140/19)

Vetus Raw Water Strainer Type 330 Ø19mm (Vetus FTR330/19)

 

[DJE]

I'm not sure how it could be full as the rate of water ingress will always equal the rate of egress. Even if you were to fill it by hand, the water would always have run down into the sea by the time you get the top screwed on tight. If it were level with or below sea level the it would be full but I don't believe that to be the normal placement.

Richard

When I start mine with the strainer empty the jet of water from the inlet hits the inside of the lid. This entrains a lot of air into the flow of water and the mixture gets drawn down to the pump. Over a few minutes the ratio of air to water reduces until the strainer is full of water.