Advice needed on over heating engine

[Jennifer McM]

6 hours ago, Alan de Enfield said:

 

Due to the lack of rain there is little flow in the rivers at the moment - if we get some 'weather' in the next few weeks you will have a serious problem - the river at Billing Aquadrome is not particularly friendly and has flooded the moorings quite frequently, it does get a fair bit of flow on it.

 

It can be 'sorted' but I think you are unlikely to get a reliable 'fix' to allow you to have your holiday in a week's time.

 

Billing with the river in flood

We passed Billing today (we're moored at Western Flavel flood gates on the EA mooring). Guess the river is about an inch or two higher than it was last month, going by the marsh marigolds which are just about underwater - presently there's a gentle flow. 

 

Weather forecast says it's going to be a couple of hours rain tonight, and tomorrow (we'll be staying put tomorrow), it looks like Monday onward will be clear. 

[nb Innisfree]

Looking at those pics it seems to me that the skin tank is plumbed incorrectly into the heat exchanger. Also copper pipe into calorifier has no means of venting air, assuming of course it's an indirect calorifier. 

Edited August 11, 2018 by nb Innisfree

[Tony Brooks]

37 minutes ago, nb Innisfree said:

Looking at those pics it seems to me that the skin tank is plumbed incorrectly into the heat exchanger. Also copper pipe into calorifier has no means of venting air, assuming of course it's an indirect calorifier. 

I agree about no vent on the calorifier coil but if the OP is getting hot water then the engine water pump would have managed to bleed the coil and as long as the OP then vented that air that might have ended up in the skin tank I doubt it will ave a major effect on the overheating.

 

I also agree that it looks a if the skin tank may be piped backwards but its hard to tell. Even if there is a heat exchanger core in the exhaust manifold it should not be in use with a skin tank so best call the manifold what it is.

 

To the OP

 

lease make sure the hot water exiting the engine goes to the top of the skin tank and the return water to the engine water pump comes from the bottom.

 

 

[mrsmelly]

Looks as though you could stick another tank on the opposite swim. This boat has tanks either side and remains more or less constant wether on tick over or being wellied.

[David Mack]

1 hour ago, mrsmelly said:

Looks as though you could stick another tank on the opposite swim. This boat has tanks either side and remains more or less constant wether on tick over or being wellied.

I thought that, but there's not a lot of room for a welder to get in there and fit a second tank , - unless you remove the engine first.

Blackrose fitted a second tank to his wide beam, where there is much more room. If you search back through the forum you might find the photos.

[TheBiscuits]

16 minutes ago, David Mack said:

I thought that, but there's not a lot of room for a welder to get in there and fit a second tank , - unless you remove the engine first.

The usual trick is to build them from the outside.  Cut a hole through the hull, and build the new skin tank from the inside out.

[David Mack]

9 minutes ago, TheBiscuits said:

The usual trick is to build them from the outside.  Cut a hole through the hull, and build the new skin tank from the inside out.

 

Indeed, but Blackrose's was fitted from the inside while the boat was afloat. Which may be an advantage in some circumstances.

[alan_fincher]

If you put the tank on the outside of the swim, you are unencombered by all the things that will inevitably get in the way.  The fabricator will probably have a hell of a task, even just making sure the engine and anything else in the engine bay stays undamaged.

By going on the outside you can invariably provide the required area in a single tank, and avoid the complexities of trying to link two tanks together, with correct flows, and no potential to air-lock.

 

We elected to have one external replacement tank, and to decommision the existing inadequate internal one.  I still think in many cases that is the way to go.

[blackrose]

3 hours ago, David Mack said:

 

Indeed, but Blackrose's was fitted from the inside while the boat was afloat. Which may be an advantage in some circumstances.

The other difference with mine was that it was pre-fabricated by a gate and trailer yard based on a drawing and plywood template that I made. Cost me £70 for the 4 sided tank and then another £60 for them to weld it in (plus the fittings) with the boat in the water. They happen to be based on the Thames at Staines, so I avoided those ridiculous boat yard prices (quoted £500 + drydock charges by UBC who also told me that welding it in with the boat in the water would never work!) The tank was only made from 3mm steel in the end as they said 4mm was harder to curve on their kit, so I got them to put those vertical bars in as I wasn't sure if the internal pressure would blow it out. Probably not but better safe than sorry... It only has one baffle as shown in my drawing, but it works fine - plumbed in series with the original tank.

 

As mentioned above, you probably wouldn't have enough space to weld it onto the inside on most narrowboats so it would have to go on the outside.

 

 

Edited August 11, 2018 by blackrose

[MtB]

2 hours ago, alan_fincher said:

If you put the tank on the outside of the swim, you are unencombered by all the things that will inevitably get in the way. 

 

Except for one thing.... the skin tank on the inside! 

 

Very important and easy for a fabricator working outside to overlook, is the need to construct the new external skin tank NOT overlapping the outside of the existing internal skin tank.

[blackrose]

11 hours ago, matty40s said:

Another place is where Martin Trnecka off the forum went as his boat was struggling on the Nene, Ouse and Lark. He used Foxboats yard over there who use the same system on most of their hire boats. 

This is what they do.

As far as I am aware he hasn't had a problem since fitting.

 

What's the advantage of doing it that way exactly? It doesn't look that much easier than fitting a proper tank, it's less secure if it hits something and you've got a lot less surface area for cooling.

12 minutes ago, Mike the Boilerman said:

 

Except for one thing.... the skin tank on the inside! 

 

Very important and easy for a fabricator working outside to overlook, is the need to construct the new external skin tank NOT overlapping the outside of the existing internal skin tank.

Shouldn't it be fitted on the other swim?

[MtB]

3 minutes ago, blackrose said:

What's the advantage of doing it that way exactly? It doesn't look that much easier than fitting a proper tank, it's less secure if it hits something and you've got a lot less surface area for cooling.

 

I'd say the advantage is it takes a LOT less time to fabricate than a proper skin tank. 

[blackrose]

Just now, Mike the Boilerman said:

 

I'd say the advantage is it takes a LOT less time to fabricate than a proper skin tank. 

Yes, I guess so - no curves. But it has some disadvantages that I mentioned too.

[MtB]

4 minutes ago, blackrose said:

Shouldn't it be fitted on the other swim?

 

Yes it should. But we have all encountered boatyards making incredibly stoopid basic mistakes!

[alan_fincher]

7 hours ago, Mike the Boilerman said:

 

Except for one thing.... the skin tank on the inside! 

 

Very important and easy for a fabricator working outside to overlook, is the need to construct the new external skin tank NOT overlapping the outside of the existing internal skin tank.

Not if you make the new one the only one you have.  When we did this ours totally covered the area used by the previous internal one.

 

Provided the internal one isn't where the inlet and outlet for the new one need to be you don't even have to have it cut out, (though we did for tidiness).

[Neil Smith]

The problem is the op does not have time to do a proper job, that expensive rad and fans he is looking into could be bought in a car breakers and fitted with a large bilge blower from the outside vent might be enough.

 

Neil

[Neil2]

10 hours ago, blackrose said:

What's the advantage of doing it that way exactly? It doesn't look that much easier than fitting a proper tank, it's less secure if it hits something and you've got a lot less surface area for cooling.

Shouldn't it be fitted on the other swim?

The idea with this approach is the pipe/tank goes right round the swim, in some boats this could give you a continuous 20' plus run in cooling water which to me makes a lot of sense.  

 

 

Incidentally wasn't there a thread a while back with some pictures of Martin Kedian fabricating an external tank? 

[blackrose]

23 hours ago, Alan de Enfield said:

 

Due to the lack of rain there is little flow in the rivers at the moment - if we get some 'weather' in the next few weeks you will have a serious problem - the river at Billing Aquadrome is not particularly friendly and has flooded the moorings quite frequently, it does get a fair bit of flow on it.

 

It can be 'sorted' but I think you are unlikely to get a reliable 'fix' to allow you to have your holiday in a week's time.

 

Billing with the river in flood

 

I moor at Cogenhoe just downstream from Billing. I'm not sure what you mean by "not particularly friendly"? Billing floods infrequently - I think only once in the two years I've been here. The river has been unnavigable due to strong flows more often than that of course, but those periods never last very long. 

 

I'm not sure where the OP is heading but I don't see a problem going either way - up to Northampton and the GU or downstream to Peterborough. As previously mentioned, at the moment the level is up by about an inch from the recent rain and the flow is perfectly navigable even on an underpowered boat. Today light rain is forecast and then you've got a few hours rain on Thursday which probably won't affect the river very much. I can't see any more rain forecast up to the 25th Aug so I would just look at the forecast yourself, have a look at the river, time your departure and get where you need to be.

[Michael Quelch]

Thanks again for all your advice, I’m still thinking about what can be done. But in the long term a new second skin tank will be fitting on the other swim. As Tony pointed out it’s only over heating when we have pushed here hard for a while so a slow chugging pace is the answer for now and not going to far in one hit so an hours slow chug then stop for a bit. 

[Tony Brooks]

1 hour ago, Michael Quelch said:

Thanks again for all your advice, I’m still thinking about what can be done. But in the long term a new second skin tank will be fitting on the other swim. As Tony pointed out it’s only over heating when we have pushed here hard for a while so a slow chugging pace is the answer for now and not going to far in one hit so an hours slow chug then stop for a bit. 

 

Take some time to think abut the cooling pipe runs if the tank is to go on the other side. If the present skin tank is on the same side as the engine cooling water connections then it may be easier and more reliable to have a larger tank fitted to the outside on that side of the swim. Te connections will probably have to outside the area of the present tank but  can't see that being a problem and as skin tanks really only dump heat from the outside skin the old tank will have little effect. Long complicated pipe runs tend to encourage air locks and this is why I do not favour a tank on the other side piped in series with the present tank

 

[blackrose]

9 minutes ago, Tony Brooks said:

 

Take some time to think abut the cooling pipe runs if the tank is to go on the other side. If the present skin tank is on the same side as the engine cooling water connections then it may be easier and more reliable to have a larger tank fitted to the outside on that side of the swim. Te connections will probably have to outside the area of the present tank but  can't see that being a problem and as skin tanks really only dump heat from the outside skin the old tank will have little effect. Long complicated pipe runs tend to encourage air locks and this is why I do not favour a tank on the other side piped in series with the present tank

 

That's exactly what I've done with my Isuzu 55 with no problems at all. I'd get the new tank installed on the other swim and if it's not adequate then at least you still have the existing tank and can plumb both in series.

[MtB]

Or do as Alan suggested in Post 40. Fit one new, big enough external skin tank on the same side and abandon the internal small one. 

[BWM]

32 minutes ago, Tony Brooks said:

 

Take some time to think abut the cooling pipe runs if the tank is to go on the other side. If the present skin tank is on the same side as the engine cooling water connections then it may be easier and more reliable to have a larger tank fitted to the outside on that side of the swim. Te connections will probably have to outside the area of the present tank but  can't see that being a problem and as skin tanks really only dump heat from the outside skin the old tank will have little effect. Long complicated pipe runs tend to encourage air locks and this is why I do not favour a tank on the other side piped in series with the present tank

 

With that in mind, would it not be better to remove the old one and replace with a new one of the correct size?

 I wouldn't risk damage to the head, etc. with a lengthy journey until it is sorted. 

[Tony Brooks]

2 minutes ago, BWM said:

With that in mind, would it not be better to remove the old one and replace with a new one of the correct size?

 I wouldn't risk damage to the head, etc. with a lengthy journey until it is sorted. 

Yes, but on a narrowboat there is not much space for the welder to work on the inside of the hull so hence the advice to get a larger one on the outside of the swim.

 

Now the OP has a good idea about at is causing the overheat then as long as they restrict running to no more than about half throttle and throttle back f the temperature starts to climb I very much doubt they will damage the head because the will not now cause an overheat.

[MtB]

8 minutes ago, BWM said:

With that in mind, would it not be better to remove the old one and replace with a new one of the correct size?

 

 

If the OP fits a new one the correct size on the outside, there is no need to remove the old one from the inside.