Why??

[Moose]

When I close the seacocks to clean out the Raw Water filters all is well and the water level stays constant in the filter BUT if I open up the seacocks when the lid is not on the filter the water runs out of the seacock WHY??? Surely the boat should sink!!!

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Moose

 

[ccscott49]

the engine stops the water running out, when you close the seacock and open the top, the water stays at the same level, when you open the seacock, the water drains out, because the top of the filters is above the water level, maybe?

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[longjohnsilver]

Sinking feeling...........

Of course it will sink, the more water that you get in the boat the lower it sits and more pressure = more water coming through what is effectively a hole in the hull.

It all means the top of the filter body is below the water line. When the sea cock's closed there's no pressure so no water comes out.

I know a very good swimming teacher, specialises in mooses, funnily enuf never seems to be very busy, maybe you should take lessons if you intend to leave top off filter......................

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[hlb]

Re: Sinking feeling...........

You've done beter than me. I did not even understand the question!!

<hr width=100% size=1> <font color=blue>No one can force me to come here.<font color=red> I'm a volunteer!!.<font color=blue>

Haydn

 

[ccscott49]

Re: Sinking feeling...........

I thought he meant the water runs down out of the filter, not out of the top. Doh! of course it would come out if the top was off and it was below the waterline. Sorry!

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[Moose]

Re: Sinking feeling...........

No, the water runs out of the hull, the water DRAINS out of the filter, but how can this happen with 12 tonnes of boat sitting in the water?

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Moose

 

[burgundyben]

Re: Sinking feeling...........

"more water that you get in the boat the lower it sits and more pressure = more water coming through"

nope, more water in boat, boat lower, boat lower is less bouyant so pressure is going down not up, eventually as boat sinks no pressure difference? yes?

ccs is right, top of filters to high to see where water level is.

<hr width=100% size=1>Sod the Healey - I think I'll buy an E-Type.

 

[longjohnsilver]

Doh

Now I understand, or not as the case may be. Didn't think mooses were that thick! Maybe it's some sort of syphoning effect, who knows, does seem strange however. I do think you should dismantle engines to see wots happening and report back. /forums/images/icons/wink.gif

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[Moose]

Re: Doh

Good, ljs has got it (see Moose's are highly intelligent clever and technically clued up animals/forums/images/icons/laugh.gif
I think I will go and dismantle the engine now, where should I start/forums/images/icons/smile.gif

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Moose

 

[longjohnsilver]

Re: Doh

But how do they fit in a small enjin compartment and undo screws and things with their hooves?

To gain better access to facilitate enjin dismantling I suggest you first get hold of a chain saw...........................................

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[duncan]

Re: Doh

yes yo can get a syphoning effect in some set ups.........as I found out to my cost!
trying to replicate the problem we removed top and opened seacock but no water came out
ran engine - no water came out
stopped engine again - no water
ran engine for a couple of minutes at 2000 revs - stopped it and water poured through the gap we had left ..............
Interestingly even if the seacock had been closed on mine it would still have poured in 'cos the BIII leg has a pickup too!

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[Deleted User YDKXO]

I thought the top of the water strainer was always designed to be above waterline level in case some idiot (not you, of corse, Moose) comes along and opens the lid without closing the seacocks or the lid seal failed


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[Moose]

Re: Doh

But I never run the engine with the Top off the filter!!(I don't want to sink the boat!)plus I would run the impeller dry because the water will drain out of the filter (through the hull) So the impeller would be sucking in air!!

I can't understand it because the Seacock is open yet the water drains OUT!!! This cannot happen, can it!!
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Moose

 

[hlb]

Re: Sinking feeling...........

The tide went out when you wernt looking!!

<hr width=100% size=1> <font color=blue>No one can force me to come here.<font color=red> I'm a volunteer!!.<font color=blue>

Haydn

 

[longjohnsilver]

Mine isn't Mike, actually quite useful to clear out any weed or other crap in it. Water comes out at a reasonable rate, probably a few inches below the waterline.

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[Deleted User YDKXO]

I think thats unusual, John. Is it the plastic topped jobbie or something more substantial?

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[ccscott49]

I revert to my first post! The filter is above the waterline, often is, the water then drains down to the waterline. equlibrium, no more no less, if the lid is off, no syphoning action etc.

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[Moose]

No, The water drains all the way down to the sea cock, so it drains far lower than the waterline.

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Moose

 

[Medskipper]

Unless the height of your raw water filter inside the vessel is higher the the water line outside you will indeed take on water and the boat will sink! Most vessels have a long strainer that comes up from the bottom of the boat and is higher than the water line, but I have seen filters that are shorter! The obvious thing to do is close the valve before taking off the top of the filter unit. The other way if you need to have the valve open, say if there is so much weed that it needs pushing out through the bottom of the boat is to find a tube that just fits neatly into the top of your strainer so that you effectively raise the height above the water line!

Regards Barry


<hr width=100% size=1>I just want to retire with my boat to the Med!

 

[ccscott49]

You have just defied one of the most fundamental rules of physics, "water finds it's own level", well done, how the hell did you do that, theres a few professors on the way.

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