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Engine and Exhaust - follow up

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ConorOwens View Drop Down
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Post Options Post Options   Quote ConorOwens Quote  Post ReplyReply Direct Link To This Post Topic: Engine and Exhaust - follow up
    Posted: 08 Jul 2009 at 10:26am
Hi,

Earlier in the year I wrote about the problems I had with water getting from the exhaust to the back of the engine.  The engine damage required a rebuild over last winter, but I could see that the root cause - the exhaust layout - also needed to be fixed.

I wanted to lift the exhaust about 6 inches before mixing the cooling water.  To do this I got a local engineering firm to make up a new pipe and mixer from stainless to fit the same flange as the old exhaust elbow.  I also bought a larger waterlock with 10 litres capacity as the old 4.5 litre one was almost full.

I've put some pictures of old and new here:
http://picasaweb.google.com/owens.conor/Contessa32Exhaust#

With the addition of the remote drain pipe to the bilge as suggested in response to my last post, I'm confident now that it will be much harder for any water to get to the cylinders.

What I wasn't expecting was that it also makes starting the engine much easier.  I think that the initial back pressure of only a short pipe and then a full water lock was quite difficult to overcome. Now it starts very quickly.  Easier on the battery and the skippers peace of mind!

Cheers,

Conor.
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Mark View Drop Down
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Post Options Post Options   Quote Mark Quote  Post ReplyReply Direct Link To This Post Posted: 02 Sep 2009 at 5:18am
Conor,

Looks like a first class installation.  The only addition I would suggest is a vacuum break in the water hose.

Mark
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Conor Owens View Drop Down
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Post Options Post Options   Quote Conor Owens Quote  Post ReplyReply Direct Link To This Post Posted: 02 Sep 2009 at 12:19pm
Hi Mark,

Good point - I didn't mention it or include it in the pictures, but there is a siphon break in the hose between where it comes out of the heat exchanger and the injection point.  It is fitted as high as I could get it under the step at the front of the cockpit.

Various forums say that this is a point to service as they can become blocked by salt crystals but I found mine totally clean after several years of never even looking at it.  Perhaps that sort of blocking only occurs in warmer climes - and not on the west coast of Ireland!

Cheers,

Conor.
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St Paddy View Drop Down
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Post Options Post Options   Quote St Paddy Quote  Post ReplyReply Direct Link To This Post Posted: 14 Feb 2010 at 5:20pm
Looks like a good well supported installation. I let my antisyphon pass water so that I sit in it and get wet bum, then I know all is well. I have changed 2 engines and rebuilt one Volvo, all had water in the head from the exhaust. Do make sure that the antisyphon is not able to get water in it. Example side combing locker drains blocking with leaves filling up and tipping water into the engine. I have seen it happen 
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Post Options Post Options   Quote St Paddy Quote  Post ReplyReply Direct Link To This Post Posted: 14 Feb 2010 at 5:53pm
Just quick I haven't looket at it too close but you should have 12"drop from the injection point to the water trap rise to the top of your aft locker combing and drop to the skin fitting. If you have this then you will be fine fom now on. 
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nordlys3 View Drop Down
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Post Options Post Options   Quote nordlys3 Quote  Post ReplyReply Direct Link To This Post Posted: 27 Jul 2010 at 3:25pm

I have been interested to read your posts, as we think we are having problems with sea water coming in through the transom and causing some sort of hydraulic lock up.  (The engine won’t turn over at all and the water lock seems to be full) it is only a problem after we have a really good sail and need to turn the engine on go get into harbor!

 

We have fairly recently bought our contessa 32 in which we are currently sailing round Britain with a brain tumour (see our website www.contessa32.co.uk ) for details.

 

We have a beta 20 engine, and have a raised pipe before the injection point, then goes to a water lock, through a 45mm exhaust pipe which loops up to the top of the locker in the transom before it exits down.

 

What I’m interested to know is if any of you just have a raised pipe up to the top of the locker or whether you use a goose neck?

 

Also do you have any experience in the use of a valved deck fitting to only allow water in one direction.

 

The other thing I have been considering is whether it matters which side of the boat the raised exhaust pipe in the transom should be.  If it was on the opposite side to the outlet it would have more rise whilst healing on one tack, and on the other the outlet would it's self be further from the water line.

 

Any advise you have we would be much appreciated.  We are going to see Jeremy Rogers when we pass lymington, but it is causing a real problem, and we are worried about until we get there.

 

Thanks

 

Roger

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Conor Owens View Drop Down
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Post Options Post Options   Quote Conor Owens Quote  Post ReplyReply Direct Link To This Post Posted: 09 Aug 2010 at 11:35am
Hi Roger,

One thing you might try is to look on the water lock to see if it has a drain plug. If there is then you could experiment with draining this after you have finished motoring and see if after sailing you have the same problem/symptoms when restarting the engine.

If this helps then you might be able to rig a hose from the drain plug to a point under the cabin sole where you can access it more conveniently to drain it into the bilges.  

This drain was suggested on an earlier post and I included this in my remedial work.  Under the cabin sole I simply close off the pipe with a jubilee clip around a piece of hardwood dowel.  A loop of whipping twine held by a cable tie goes through the jubilee clip and the dowel to stop them both dropping into the bilge!

Hope this helps,

Conor.
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Keny View Drop Down
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Post Options Post Options   Quote Keny Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep 2010 at 10:41am
Hi Roger
Have just noticed your problem. We have a similar setup to yours (Beta20,swan neck exhaust, water lock and exhaust pipe water trap.). Our water lock is an Aquafax 7 litre and the exhaust differs from yours in that it enters the transom on the starboard side and tops in the centre of the transom about 3 inches below the deck. This has given us no problems whatsoever and the engine always (touch wood) roars into life on the first turn or two.
Hope this helps
Ken
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