Canal cooled BMC engine.

[pete.i]

Hello everyone.

 

Well we have bought our first narrow boat. We had it surveyed today and the surveyor, although laying it on a bit thick "so that I couldn't sue him if I found something he hadn't picked up" said that it was very nice boat and that if I did all the work he recommends it would be worth more than I am paying for it. I will, of course, have to pay for some of the work but the vast majority of it is tidying wires and tightening nuts in the engine bay which is not beyond me. We are going to have it professionally painted as well which is going to eat into any profit I might make but as we have no intention of selling it for at least ten years I dont think that is a problem. I was going to do the paint job myself but having looked at some of the work that the painter guy has done I soon realised that there no way in the world would I get it as good as he does.

 

Anyway one of the things that the surveyor did pick up was the fact that the engine cooling water entry point on the hull had an external filter. This was actually half full of freshwater mussels. He suggested that I do away with that filter and get an internal filter fitted. Now I haven't actually looked at the feasability of this as the boat is out of the water on a trailer being blacked and having new anodes fitted. Obviously changeing and cleaning an internal filter would be a lot easier than cleaning an external one as the only way I can do that is if the boat is out of the water or I don my snorkel gear and that I really dont fancy doing that.

 

So basically my question is; Has anyone done this? Apparently canal cooled engines are a bit of a rariety. Is this do-able?

 

Excuse my rattling on a bit there at the beginning but this is our first narrow boat and my missus and I are very very enthusiastic about it. Well probabaly more than enthusiastic LOL.

 

Cheers for any answers

 

Pete.I

 

OOPS sorry I just realised that this is in the wrong place. Please move for me mods to maintainence. Cheers

Edited March 23, 2010 by pete.i

[Albion]

Hello everyone.

 

Well we have bought our first narrow boat. We had it surveyed today and the surveyor, although laying it on a bit thick "so that I couldn't sue him if I found something he hadn't picked up" said that it was very nice boat and that if I did all the work he recommends it would be worth more than I am paying for it. I will, of course, have to pay for some of the work but the vast majority of it is tidying wires and tightening nuts in the engine bay which is not beyond me. We are going to have it professionally painted as well which is going to eat into any profit I might make but as we have no intention of selling it for at least ten years I dont think that is a problem. I was going to do the paint job myself but having looked at some of the work that the painter guy has done I soon realised that there no way in the world would I get it as good as he does.

 

Anyway one of the things that the surveyor did pick up was the fact that the engine cooling water entry point on the hull had an external filter. This was actually half full of freshwater mussels. He suggested that I do away with that filter and get an internal filter fitted. Now I haven't actually looked at the feasability of this as the boat is out of the water on a trailer being blacked and having new anodes fitted. Obviously changeing and cleaning an internal filter would be a lot easier than cleaning an external one as the only way I can do that is if the boat is out of the water or I don my snorkel gear and that I really dont fancy doing that.

 

So basically my question is; Has anyone done this? Apparently canal cooled engines are a bit of a rariety. Is this do-able?

 

Excuse my rattling on a bit there at the beginning but this is our first narrow boat and my missus and I are very very enthusiastic about it. Well probabaly more than enthusiastic LOL.

 

Cheers for any answers

 

Pete.I

 

OOPS sorry I just realised that this is in the wrong place. Please move for me mods to maintainence. Cheers

 

Are you sure that what you are calling an external filter isn't what is commonly called a mud box? This should be a large chamber with a grilled entry from the canal which probably will have a perforated plate inside it to act as a finer filter. There is then usually a washable, (removable to wash) filter in a filter housing mounted between the mud box and the engine. The purpose of the mud box is to slow down the velocity of the water coming in and to let larger solids and most of the mud settle out in the slower flow before the fine removable filter gets rid of the bulk of the rest.

If what you have is a mud box then it is nearly vital for a raw water cooled engine as you drag along the bottom of the canal stirring up the mud and dragging in all the other rubbish. It shouldn't have fresh water mussels in it (they get everywhere) but it serves a useful function if it truly is a mud box.

Roger

[alan_fincher]

Hard to tell from your descriptions exactly what you have.

 

If it's out of the water, is it possible to post pictures of both what you can see on the outside, and of anything where the cooling hose connects to it on the inside.

 

What you have is called "raw water cooling", and is relatively unusual these days, except on many historic working boats, that traditionally operated perfectly satisfactorily this way.

 

(Most modern leisure narrow- boats with water cooled engines circulate their cooling water through a closed "skin tank" built on to the side of the hull, and which works like a car radiator, other than being cooled by canal water, rather than air.)

 

Raw water cooling can be fine, but equally if not done well it can be a nightmare.

 

I operated a poor example of it in the 1970s, where what was presented to the canal was just an open pipe of around 2" diameter, which sounds like maybe what it has been suggested you move toward. This will inevitably suck in large amounts of mud, weed, carrier bags, etc, so unless your internal filtering arrangements are quite clever, they will still clog up.

 

But if you have some kind of holed "grid" over the external pipe or opening, (perhaps what you have), then it's possible that things like bags and weed just get sucked to cover that, and water is cut off from getting inside at all. (A couple on here have a boat like that, and have much written about their difficulties, that can involve donning a wet-suit to sort it out - I think they have either converted to skin tank cooling, or hope to do so?).

 

But post some pictures, and people will make some suggestions, but don't give up a mud box, if that's what it already has. You need it!

 

Really the only way of doing it does involve the "mud box" that Albion describes.

[LEO]

Hi,

 

Fine purchase, congratulations, we ran this boat for 16 years and the cooling system only blocked slightly once at a rally on the Wendover arm when the inlet pipe was moored close to the shallow muddy bank.

 

There is a strainer of sorts, situated externally on the swim, the hole being covered with a nylon cover, as has been said this works well - even on the Tring summit during the Autumn leaf fall.

 

The boat's engine has a sealed system which allows for frost protection with anti freeze mixture, this water and the and the exhaust is cooled by raw water via a heat exchanger, the water for this first passing through a gearbox oil cooler and then an engine oil cooler and pumped from the canal or river by a Jabsco pump, exiting via the exhaust.

 

It's a shallow draughted boat which does not drag along the bottom pulling up lots of mud and really a 'mud box' is a bit extreme, I would check where the freshwater mussels are before adjusting the intake system.

 

I did buy an in-line filter from UBC, but never felt the need to fit it, it's also in UPVC or polypropelene so it's something else to 'frost protect'

 

We ran the boat extensively on rivers and canals it was equally at home on both, if a blockage is experienced, turn the engine off, this will stop the water being drawn into the boat and the material covering the inlet will float free, re-start the engine and off you go.

 

Leo

[RobinJ]

...

Anyway one of the things that the surveyor did pick up was the fact that the engine cooling water entry point on the hull had an external filter. This was actually half full of freshwater mussels. He suggested that I do away with that filter and get an internal filter fitted.

...

So basically my question is; Has anyone done this? Apparently canal cooled engines are a bit of a rariety. Is this do-able?

...

Is it a mud box or simply a brass inlet with bars to stop large objects entering? (I have never seen an external filter where you have to get at the element from outside).

 

No as rare as people seem to think!

[Athy]

Most, if not all, GRP boats have this type of cooling system, don't they?

[koukouvagia]

.. if a blockage is experienced, turn the engine off, this will stop the water being drawn into the boat and the material covering the inlet will float free, re-start the engine and off you go.

 

Hmm - up to a point Lord Copper. I've made a DIY filter unblocker which consists of a wire brush (the sort you attach to an angle grinder) bolted at right angles to a pole. I can then scrape this over the surface of the water inlet and clear the holes of weeds which, unlike plastic bags etc., stay resolutely in place and don't drop off.

[Evo]

Hmm - up to a point Lord Copper. I've made a DIY filter unblocker which consists of a wire brush (the sort you attach to an angle grinder) bolted at right angles to a pole. I can then scrape this over the surface of the water inlet and clear the holes of weeds which, unlike plastic bags etc., stay resolutely in place and don't drop off.

 

We have this problem all the time....we've had all sorts of brushes at funny angles on poles....we've even made our own very fancy tig welded alum space program looking device. That got stuck in a willow tree on the Ashby last year - eventually dropping in the cut - and was lost forever.

When the Oxford canal around Coventry had that duckweed problem it was a joke, our pepper pot inlet was blocked all the time. We have a plastic Vetus waterlock and rubber exhaust pipe so no water and exhaust system meltdown - oh noo!, a right pain in the arse.

 

Our raw inlet is a 2" pipe with a coarse grill (pepper pot) welded into the side of the swim with a large ball valve stop cock on it. It then goes direct to a Jabsco pump which pumps it through the exhaust manifold heat exchanger and out into the exhaust pipe.

 

I put up with it because its so dammed nice to listen to....theres no brrrm brrrrm of a van engine.

 

As a an example of how much grief your likely to get, during our last fortnight holiday I had to switch off engine 3 times for 15 secs - for clumps of weeds or big black bin liners to clear, and I had to lie on the bank twice to pull out long trailing river bottom type weed. DO NOT REV ENGINE WHEN IN THE BOTTOM OF A LOCK - it will suck in all sorts of crap.

 

I generally lie on the bank and give it a good 'scraping' clean every year. My main worrry though is if people borrow the boat and dont bother doing anything about a blockage, or the jabsco impeller breaks down on them, I probably end up with a very big bill.

[FadeToScarlet]

Hmm - up to a point Lord Copper. I've made a DIY filter unblocker which consists of a wire brush (the sort you attach to an angle grinder) bolted at right angles to a pole. I can then scrape this over the surface of the water inlet and clear the holes of weeds which, unlike plastic bags etc., stay resolutely in place and don't drop off.

 

 

My solution was a hosepipe from the shower outlet, run back through the boat and pushed into the filter, to pump water out of the inlet.

 

I only went swimming once, to remove a very stubborn plastic bag. SWMBO went a couple more times.

 

WHat I would have given for a proper mudbox!

[LEO]

Hi,

 

Interested in both Evo and F to S's replies and followed the latter's problems via his blog last year. Can only say the blockages I encountered were as detailed, which in 16 years was not bad.The fine nylon tea - type strainer with round side out helped enourmously - I don't think F to S had one of these until until he reached the R.Cam at the end of his journey.

 

I also found the 30 ft length of the boat helped - we rarely picked up junk around the prop and never on rivers.

 

Mud box - not sure if this would help as I had no problems with mud and few poly bags make it through to the mud box. We also had a fair exposure to Duckweed on the canal and silkweed on the Nene

 

The inlet hole was about 1".

 

I think the size of pulley driving the Jabsco pump helps, if you get the ratio wrong the pump will rotate too quickly and draw in too much water and create a huge level of suction, water circulation has to be just right, we got this ratio right after experimenting with various Picador pulleys, geared to the size of the crankshaft pulley.

 

To much water going through the various heat exchangers will not cool the water properly - think of a keel cooler with no baffles, you get the same effect with a high water through put in a heat exchanger.

 

Jabsco impellers are not very forgiving and expensive, but I only had to change one of these and that wore because I forget to undo the seacock once before I started the engine.

 

Leo.

Edited March 24, 2010 by LEO

[RobinJ]

My solution was a hosepipe from the shower outlet, run back through the boat and pushed into the filter, to pump water out of the inlet.

When last in dry dock, found some plastic sucked up through the inlet.

I have now started pouring water down the filter before I clean it out to ensure the inlet isn't blocked, if the level drops I know it is clear (mostly weed)! Otherwise I use the matress inflation pump (stirrup type), which also doubles for unblocking the sink outlets too!

[LEO]

Hi,

 

I also found the advantages of a water cooled exhaust when we went downstream through Shiplake Lock during Henley Royal reggatta one year.

 

A punt full of blazered, well turned out, well oiled ladies and gents came into the lock behind me. They objected to a dirty black boat coming to the festivities and started fendering off their boat with poles and paddles, generally using my paintwork as a point of purchase. The Lock Keper noticed this and suggested that their behaviour was anti-social and had better stop.

 

We came to exit the lock and I tried to warn the good people that we had a water cooled exhaust and not to come too near, but they ignored this, the engine somehow got started on near full throttle out of gear - it's amazing how far and how much water and exhaust smuts go at times - especially on blazers and dresses. The Lock keeper smiled, one got the impression it made his day.

 

Leo

[Phil Ambrose]

Most, if not all, GRP boats have this type of cooling system, don't they?

 

Yes. (short and sweet)

 

Phil

[laser]

Hello everyone.

 

Well we have bought our first narrow boat. We had it surveyed today and the surveyor, although laying it on a bit thick "so that I couldn't sue him if I found something he hadn't picked up" said that it was very nice boat and that if I did all the work he recommends it would be worth more than I am paying for it. I will, of course, have to pay for some of the work but the vast majority of it is tidying wires and tightening nuts in the engine bay which is not beyond me. We are going to have it professionally painted as well which is going to eat into any profit I might make but as we have no intention of selling it for at least ten years I dont think that is a problem. I was going to do the paint job myself but having looked at some of the work that the painter guy has done I soon realised that there no way in the world would I get it as good as he does.

 

Anyway one of the things that the surveyor did pick up was the fact that the engine cooling water entry point on the hull had an external filter. This was actually half full of freshwater mussels. He suggested that I do away with that filter and get an internal filter fitted. Now I haven't actually looked at the feasability of this as the boat is out of the water on a trailer being blacked and having new anodes fitted. Obviously changeing and cleaning an internal filter would be a lot easier than cleaning an external one as the only way I can do that is if the boat is out of the water or I don my snorkel gear and that I really dont fancy doing that.

 

So basically my question is; Has anyone done this? Apparently canal cooled engines are a bit of a rariety. Is this do-able?

 

Excuse my rattling on a bit there at the beginning but this is our first narrow boat and my missus and I are very very enthusiastic about it. Well probabaly more than enthusiastic LOL.

 

Cheers for any answers

 

Pete.I

 

OOPS sorry I just realised that this is in the wrong place. Please move for me mods to maintainence. Cheers

 

 

Hello everyone.

 

Well we have bought our first narrow boat. We had it surveyed today and the surveyor, although laying it on a bit thick "so that I couldn't sue him if I found something he hadn't picked up" said that it was very nice boat and that if I did all the work he recommends it would be worth more than I am paying for it. I will, of course, have to pay for some of the work but the vast majority of it is tidying wires and tightening nuts in the engine bay which is not beyond me. We are going to have it professionally painted as well which is going to eat into any profit I might make but as we have no intention of selling it for at least ten years I dont think that is a problem. I was going to do the paint job myself but having looked at some of the work that the painter guy has done I soon realised that there no way in the world would I get it as good as he does.

 

Anyway one of the things that the surveyor did pick up was the fact that the engine cooling water entry point on the hull had an external filter. This was actually half full of freshwater mussels. He suggested that I do away with that filter and get an internal filter fitted. Now I haven't actually looked at the feasability of this as the boat is out of the water on a trailer being blacked and having new anodes fitted. Obviously changeing and cleaning an internal filter would be a lot easier than cleaning an external one as the only way I can do that is if the boat is out of the water or I don my snorkel gear and that I really dont fancy doing that.

 

So basically my question is; Has anyone done this? Apparently canal cooled engines are a bit of a rariety. Is this do-able?

 

Excuse my rattling on a bit there at the beginning but this is our first narrow boat and my missus and I are very very enthusiastic about it. Well probabaly more than enthusiastic LOL.

 

Cheers for any answers

 

Pete.I

 

OOPS sorry I just realised that this is in the wrong place. Please move for me mods to maintainence. Cheers

[laser]

hi pete

 

I also have a raw water cooled bmc engine (thru a heat exchanger) i got fed up with the mud box getting blocked and having to be cleaned out after every trip,so i scrapped it and fitted a vetus water filter the type with the clear plastic lid you can see when it needs the filter element cleaning because the water level rises above it. this is a lot less frequent than the mud box and takes only a few mins .The reason is due to the position of the water inlet fitting position, it is just the simple brass type with a grill shaped thicker at one end than the other placed thru the counter plate at the side of the weed hatch the thick end faceing the bow ,the theory is that the water is so turbulent here due to the prop ,that debris passes rapidly out of harms way. this certainly works for me ,but you must fit a ball valve directly onto the fitting which is in my case 1/2 bsp.after doing its job the water then returns to the canal a little cleaner and warmer making friends on the way with the o so quiet exhaust gasses well worth the effort

 

laser

[pete.i]

Hi Laser and everyone.

 

Well I found out what the filter thing is on the side of my hull. It's actually a nylon tea strainer that has had the handle cut off. A piece of round hardwood has been bolted to the hull just to the side of the water entry hole and the diameter of the circular piece of hardwood is the same outside diameter as the inside diameter of the tea strainer. I have found this out because the guy that is blacking the hull hit it with his rotary wire brush and now it has no mesh left LOL. It was held on to the hardwood disk by 2 self tapping screws. Thats a hell of a description for something so simple but to be honest it works, well it did before the blacking guy stuck his wire brush through it.

 

So now I'm trying to find another plastic tea strainer to replace it. I think that, probably I will end adapting something else to do the job. The only trouble is the boat is back in the water on Sunday and then it will be almost imposiible to get at. That isn't quite as bad as it seems though because the boat is coming out again at the beginning of June to have the superstructure painted so I will be able to get at it again.

 

Personally I think the tea strainer idea is a much better idea that an internal filter because it's going to be much more work to fit an internal filter. If something is sucked in with an internal filter then its going to go up a length of pipe first before it encounters the filter making it much more difficult to remove. If something is sucked in with an internal filter fitted the pipe and the filter will have to come apart to remove it. The tea strainer idea is much better as stuff dosen't actually get into the boat. It's been there for the best part of 20 years, maybe more until the blacking guy destroyed it, and it has obviously done the job.

 

Pete

[RobinJ]

Personally I think the tea strainer idea is a much better idea that an internal filter because it's going to be much more work to fit an internal filter. If something is sucked in with an internal filter then its going to go up a length of pipe first before it encounters the filter making it much more difficult to remove. If something is sucked in with an internal filter fitted the pipe and the filter will have to come apart to remove it. The tea strainer idea is much better as stuff dosen't actually get into the boat. It's been there for the best part of 20 years, maybe more until the blacking guy destroyed it, and it has obviously done the job.

I was thinking of something like this Brass Inlet

[pete.i]

Hi robinj

 

That looks just the job. I shall buy that and have a play when it's out of the water in May.

 

Thanks for that.

 

Pete

[FadeToScarlet]

The Duck had a simple triangular baffle plate over the inlet, so the water had to flow backwards and into it, before it came up to a Vetus clear-lidded strainer, and from there into the engine heat exchanger.

 

Annoyingly, our surveyor recommended that we cut slots into the baffle plate, so as to reduce any vacuum- but this completely reduced its effectiveness and it became blocked much more often. We cable tied on some plastic mesh over the entrance (having experimented with an old pair of SWMBO's tights, which worked very well!) and this helped, but it wasn't perfect.

[Evo]

Hi robinj

 

That looks just the job. I shall buy that and have a play when it's out of the water in May.

 

Thanks for that.

 

Pete

 

 

I've been looking at all sorts of strainers and methods of protecting the inlet from crud......but I cant come up with anything. My fear is, as it is at the moment I will always be able to fix it with the boat in the water, If I start putting strainers and deflector shrouds over it then I cant get at it properly without getting the boat out the water.

 

My latest harebrained scheme is a lorry air brake compressor, or car aircon unit ,and a small cylinder. I could braze an air fitting to the inlet pipe and some strategically placed nozzles in the pepperpot, rig up a push button, or even an automatic system, that blasts air out the pepper pot to clean it. A bit excessive......but could be handy having compressed air on board. Cant think what for...blowing up a lylo...

Edited March 26, 2010 by Evo