Help Sinking!

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Just had boat out of water (P35) antifouled and spived up. Launched her today first the good news top speed increased to 22kts , best performace ever considering 2x 165hp. It's all down hill from now. The starboard engine over heating alarm starts ,this is on going problem. Refilled with water , noticed that engine room is flooding 2 miles from home , the water is coming in like a constant hose, 18 inches deep. All hands to the pumps auto bilge not coping manual bilge pump keeps water at constant level , now covering batteries and rising above engine mounts.
We limp back to Brighton Marina water not rising so quickly at slow speeds.
We think water coming in through stern glands as no other points of entry seem possible . Have now tightened stern glands as there was a constant drip while stationery. Does any one know why we should get this problem boat out of water for six days does extra speed put pressure on shafts? There was a bit of play on starboard shaft when out of water but we chose to ignore it . (no more money) Any advice ?
 
A constant SLOW drip when stationary is normal, dont tighten them too much, you will destroy the shaft/seal area. I don't think the water would come in that fast, even if the stern glands had no shaft in them, I would be looking somewhere else! Maybe a hose to the engines, especially the starboard one, that may not have been getting enough water perhaps? What ever, you could try starting each engine individually and see if the water is coming in, but stern glands, I think not. IMHO of course.
 
did you use a power polisher,i did on my last boat, it losend a skinfitting that took in water as the stern lowerd underfullpower. ps i will lern to spell and type,

rich :-))
 
See article in Yachting Monthly May 2002, page 44.

Story of a yacht taking in water through stern gland, could well be the same problem you have.


All the best


Brian
 
I think you are right Colin, as we have had an overheatig prob . on stbd eng. for some time which i have chose to ignore by just topping water level each time we use the boat . The water was coming out of the header tank under pressure, now we have increased the performance the engine is reving faster it has produced more pressure and blown a hose or something hence forced water in boat . Sounds serious or could it be just a hose forced off ?
More investigations today . Also i left seacocks open overnight if water intake system is leaking will it continue flood when engines not running. Thanks for your advice!
 
Mark
Please excuse me for mentioning but don't forget that the cooling water (in engine & header) is mainly pressurised by the water temperature not engine speed.

As the water heats it expands within the fixed space of the fresh water system causing the pressure in there to increase -so be extremely careful if you remove the header tank cap to have a look see when the engine is hot even when its not running - the boiling water will spurt out and can easily scald - and it'll go everywhere.else anyway Usual advice is always to wait until things cool right down.

I seem to recall that the increased pressure in the system also increases the boiling point of the water and apart from the pressure generally forcing out the water through the filler when you remove the cap, some of the water immediately boils when the pressure is reduced which adds to the effect.

Sorry if you know all this already but your mentioning that water pressure relates to engine speed usually only relates to the sea water cooling system, where there's no such danger of course.

Seems like you might have 2 problems - the previous slow leak from the fresh water side requiring you to top up the header tank and a second sea water leak somewhere causing the bilges to flood - (was the bilge water hot (ie from the "fresh" side or sea water?)
 
Reading all the cooling water assumtions, the yacht in the article just made port with a leaking stern gland. Engine mount failure had caused the prop shaft to vibrate, and a water leak that bilge pumps could just keep up with.
Slight play in the the one prop shaft bearing could well be giving same problem.


Brian
 
Stern glands definately worth investigation. I'm lead to believe that correctly adjusted they should drip slowly when in use, not when stationary. No drip in use means not enough lubrication.

But going on from your cooling water situation, I had water coming in once, and it turned out to be a failing raw water pump which was sending half the water round the wngine and half into the bilge! This was on a raw water cooled petrol engine, but although yours probably have a sealed fresh water cooling, you still have raw water being pumped in to cool that so guess the same thing is possible.

Also have heard of an exhaust leak causing water into bilges, the raw water exits through the axhausts, so a split or a loose exhaust hose could still allow the exhaust gases to exit normally, but the cooling water could be pouring into the bilges instaed of out of the exhaust outlet.

Ari.
 
Re:Your off your head

Surely its a dangerouse thing to do, re you know there are problems !!!!!!! and you still went out.

I think the head gasget is suspect , I take it for granted that you would have previousely checked for leake's ( hoses ect ).
As You proberly know but just incase you didn't , if your head gasget has gone then the actual cylinder can and proberlly will pressuerise the water system and force the temperature up of couse.
Stern gland
A drip a min, is what you should aim for that's the rule taught to me as a training marine engineer , I agree with that.
On long runs its better to have more comming in because of the work that's going on ,I know it's difficult to check some systems but if you have the ordanary type, after a reasonable run you should be able to feel warmth but not heat !! on the stern gland, warmth is fine but heat things are to tight.
Also is it greaser or oil lubricated , I like to pump a bit of grease in before a days run and as nowa days the packings usualy have teflon ,sylican grease is fine .Oil type keep the resevoir toped up .

As for the rubber types if the rubber bellows shows signes of perishing change !!.

A compession check should point to the actual cylinder thats down , no reasone why you cant do this your self as there is no great secret to carrying out the process.
Why not do the job your self if it is a head gasket the only difficult bit is getting the head off with out breaking the head bolts.
Putting back, the main thing is making sure you have cleaned and checked over every thing. But be sure to check for cracks on the clinder head and also make sure its not distorted.
Mick


http://homepage.ntlworld.com/boats
I want a big steel ex trawler / tug v / cheap or swap for tug
 
Water loss is from fresh cooling water, therefore limited flooding, but head gasket may cause loss and over heating.
But would have thought a bit of play in star'd shaft could well be causing the shaft to float in gland and let in water, also the increase in revs could be generating added vibration.


Brian
 
Thanks for advice , now traced leak . The water was coming from 6'' dia. hose which had come off heat exchanger / exhaust area. I don't know if it was related to overheating or coincidence that it came off after back in water. The water was coming in the boat as fast as the pump was running. I hpoe it was just jubilee clips that had come loose. If we had looked closer in engine room when we noticed water we would have shut down sbd. eng. Unfortunately we continued for 2 miles back to marina with engines on so you can imagine how much water came in. Anyway i still have overheating problem , so will try flushing eng. change thermostat thats as far as i can go without professional help.
 
It had to be something like that, by the amiount of water we were talking about and rev dependant, I'm glad I could be of help! You just need to investigate this overheating problem now, all of the below statements regarding head gasket etc, could be right but look for the simple things first, blockages poor pump performance (both of them) etc. It's often the simplist thing thats overlooked.
 
I would start with the pump, check the impellor and then the stacks in the header tank and oil/inter coolers. Surprising how furred up they can get and what a difference it makes to the cooling performance. Remember to rod them against the flow.
 
It's an archaic term, used when boiler tubes were "rodded", that is a metal rod was rammed through the tubes, to clean any accumalated debris from inside each tube, because the debris came into the tube from one direction, you always "rodded" the tube, (pushed the rod through the tube) against the direction of flow, as then you were forcing the debris out the way it came in! Simple Eh! The things one remembers! Amazing! I "rod" my heat exchangers every two years as a matter of interest.
 
Mark

This may sound obvious but I've made this mistake twice before and I wouldn't want you to go to the trouble of doing compression tests, convincing yourself that one cylinder is low, ripping off head and replacing the gasket only to find out that there is no change. Before you do anything else change the thermostatic valve in the cooling system. If I'm wrong you'll waste a couple of quid, if I'm right I've saved you a load of grief.



--
Tides - Never there when you need one.
Wind - Always there when you don't.

KevL
 
Mark, 40b engines take a lot of cooling, the heat exchanger is too small for the hp rating, so has to be tip top cond to work properly, check for play in pump shaft, also tubes in oil cooler, intercooler as well, check exhaust elbow, remove elbow look down robber exhaust for any sign of narrowing or total collapse, look into elbow from exhaust end check that holes are large between casting and centre mixer piece they are usuall blocked, I once spent a lot of time on a certain boats overheat problem and found this was the cause of it all, also 2 old anodes were welged inside the elbow water inlet pipe, going on to the main water heat exchanger, the rubber end collapse causing water not to flow into and out the tubes so remove it inspect and fit a new one if the centre piece is not straight, if you fit a new one smear sillicone sealant across the middle, good luck.

Paul js.
 
I had similar problem last year when I bought my first boat. engine overheated and rubber hose in exhaust connection melted due to lack of water cooling. Later found no blades on water impeller!
 
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