Engine cooling

[Rufus1010]

Could my narrowboat have both keel cooling and raw water cooling?  I seem to have a narrow tank to the side of the engine bay with two inlet/outlets and a relief at the top but I also have a raw water cooling setup. I'm unsure as I purchased the boat whilst it was on hardstanding and couldn't ask the previous owner.

[ditchcrawler]

2 minutes ago, Rufus1010 said:

Could my narrowboat have both keel cooling and raw water cooling?  I seem to have a narrow tank to the side of the engine bay with two inlet/outlets and a relief at the top but I also have a raw water cooling setup. I'm unsure as I purchased the boat whilst it was on hardstanding and couldn't ask the previous owner.

A few photos and a bit more info would help, make of engine, builder of the boat etc

 

[Tracy D'arth]

Could have keel tank cooling and water injection into the exhaust.

Much more detail and pictures needed if you want an answer, we are not all mind readers.

[GUMPY]

Mine started life with a skin tank and water injection exhaust.

Skin tank was ditched in favour of heat exchanger.

If you follow the water pipes back from the exhaust where do they go?

[Tony Brooks]

2 hours ago, GUMPY said:

Mine started life with a skin tank and water injection exhaust.

Skin tank was ditched in favour of heat exchanger.

If you follow the water pipes back from the exhaust where do they go?

 

Probably into the exhaust manifold, with another thin one to the raw water pump, but then the question is how many hoses are attached to it. I think that I would rather wait until we get the photos.

[blackrose]

18 hours ago, Rufus1010 said:

Could my narrowboat have both keel cooling and raw water cooling?  I seem to have a narrow tank to the side of the engine bay with two inlet/outlets and a relief at the top but I also have a raw water cooling setup. I'm unsure as I purchased the boat whilst it was on hardstanding and couldn't ask the previous owner.

 

If it turns out you've got both, I think the next question is do you need both?

 

If keel cooling can be made to work (i.e. if it keeps the engine cool enough when pushed hard for prolonged periods against river currents), then especially for the inland waterways this "self contained" system is a much better solution than raw water or indirect raw water cooling. There's much less to go wrong, no possibility of clogged up mud boxes or blocked inlet strainers, and no need for any winterisation because it's already full of antifreeze.

Edited June 16, 2023 by blackrose

[ditchcrawler]

1 hour ago, Tony Brooks said:

 

Probably into the exhaust manifold, with another thin one to the raw water pump, but then the question is how many hoses are attached to it. I think that I would rather wait until we get the photos.

If we get any photos

[Tony Brooks]

5 minutes ago, ditchcrawler said:

If we get any photos

 

Again, and again, but give the OP time, they might not be on the boat to take photos.

[ditchcrawler]

22 minutes ago, Tony Brooks said:

 

Again, and again, but give the OP time, they might not be on the boat to take photos.

But they were here an hour ago and could have said so, or even acknowledged all the suggestions

[Rufus1010]

Sorry all, thanks for all the great responses so far. I'm currently working with very limited availability. When home later I'll try to dig out some photos. 

Forgive my ignorance as I'm very new to narrowboats at 61 years old!  I will do my best to provide pics and more information when I can.

[ditchcrawler]

18 minutes ago, Rufus1010 said:

Sorry all, thanks for all the great responses so far. I'm currently working with very limited availability. When home later I'll try to dig out some photos. 

Forgive my ignorance as I'm very new to narrowboats at 61 years old!  I will do my best to provide pics and more information when I can.

Great stuff, as they say a photo is worth a thousand word if you can see the right bits of course. 

[GUMPY]

Sorry I meant follow the water pipe back from the water injection point and see where it goes to. If it goes to a pump then to  the oil cooler and finally back to the inlet it's just a water injection exhaust. If it goes through a heat exchanger, header tank on the engine then it's heat exchanger cooled.

I can't think of a simple way to plumb a HE and a skin tank so they work together. 

To give you some idea what a water injection exhaust  might look like in the picture the water intake is through the copper pipe on the right it goes through the oil cooler goes in copper pipe  round the Left side of the engine and the  water returns to the exhaust via the copper pipe over the to

 

OH what engine do you have and what HP is it?

 

 

 

 

Edited June 16, 2023 by GUMPY

[Rufus1010]

Sorry all, thanks for all the great responses so far. I'm currently working with very limited availability. When home later I'll try to dig out some photos. 

Forgive my ignorance as I'm very new to narrowboats at 61 years old!  I will do my best to provide pics and more information when I can.

[Tony Brooks]

But a heat exchanger engine will have the raw water flowing, raw water pump > manifold with heat exchanger > exhaust injection point.

 

A heat exchanger engine converted to run on a tank is likely to run raw water pump > manifold with heat exchanger > exhaust injection point. Except, the manifold may or may not still have a heat exchanger core in it. Often the raw water is passed through the manifold to reduce the heat the skin tank has to dump, but on other boats the manifold is used as a header tank for the tank cooling.

 

In both the above cases, the RAW water pipes and hose will be similar sized to car heater hose.

 

If it is tank cooled then the raw water may run as per Gumpy's photo, so the raw water never gets into the manifold, but that is far from certain. The raw water may or may not pass through a gearbox oil cooler.

 

A tank cooled boat will typically have a flow like this using something like a 1.25" pipe, thermostat housing > manifold > top of skin tank > bottom of skin tank > inlet to engine water pump. If there is a gearbox oil cooler, then it should be in the cold return between tank and engine water pump.

 

There are so many variations, it is difficult to be certain. In some cases, you have extra hose connections in the manifold that are blanked off.

Thanks for the photos.

 

The thermal insulation wrapped exhaust pipe says that it is a dry exhaust boat.

 

I can't see the engine and its plumbing, but with a dry exhaust, it is almost certainly a tank cooled boat.

 

The gearbox is a Hurth and it does not use an oil cooler.

[Rufus1010]

Hi all, photos not great but best I have. On first you can just see edge of raw water cooling at the left just below my stepping board. Other two show the slim tank in the engine compartment.  The raw water cooling has the hole through the hull and a surveyor told me that was a raw water cooling system.  I later noticed the tank and there were hoses attached to what looks like a pump with a drive belt to the main engine but not to the tank?

Sorry I'm vague but the boat isn't a runner at the moment and needs a lot of work. Just trying to establish what I'm dealing with.  I want to avoid raw water cooling and wondered whether I had the bones of keel cooling.  Thanks everyone.

Sorry meant to say its an old bmc1500 and the boat is from around 1992 by Aqua Marine.

Sorry meant to say its an old bmc1500 and the boat is from around 1992 by Aqua Marine.

 

I took off what I believe was the raw water cooling system and it was indeed gunked up with slime leaves and marine growth.

[Tony Brooks]

I am afraid that we need to see the engine and cooling hoses to comment further. If it is raw water cooled the as there is no sign of water injection into the exhaust and the exhaust is wrapped, there should be two holes in the hull. Both fairly small. One low down below the waterline somewhere and another above or at the waterline, so you can see the water coming out and know if it fails.

 

Be aware that there could be all sorts of add thing and bodges on the cooling system, looking at the rust scabs on the skin tank I wonder if it leaked and something has been cobbled together.

 

You may find the skin tank is a bit small, so it may overheat when on the river.

[Rufus1010]

Sorry meant to say its an old bmc1500 and the boat is from around 1992 by Aqua Marine.

 

I took off what I believe was the raw water cooling system and it was indeed gunked up with slime leaves and marine growth.

 

Thanks everyone for the useful information so far. I've been back at the boat today getting the engine ready for removal. I took some photos below. One is an overview of the engine, one shows what I was advised was a raw water cooling system that I removed. One shows the raw water incoming through the hull the others are what I think is the coolant pump and hoses to the head of the engine. There are two othe hoses that were disconnected but look as though they should go to the skin tank?j

[Alan de Enfield]

It certainly has had (still has ?) raw water cooling. Half of the filter is in picture 2 and the belt driven pump is in picture 3.

 

I would imagine that the impeller (inside the pump) will be "beyond use".

[Tracy D'arth]

I am presuming that you intend using the skin tanks for cooling, are you sure they are serviceable?Its odd that someone has installed raw water cooling on top of an engine with skin tanks. There was probably a reason.

You have a lot of work to come on that boat.................

[David Mack]

22 minutes ago, Tracy D'arth said:

I am presuming that you intend using the skin tanks for cooling, are you sure they are serviceable?Its odd that someone has installed raw water cooling on top of an engine with skin tanks. There was probably a reason.

For example, what is going on here?

[Rufus1010]

Thanks all, it did seem bizarre to me but being such a newbie I was unsure.  The boat is a major project but I'm determined to restore her to former glory days.  Engine is being removed next week, all new channels and some other welding being done around engine bay, chines replaced and some pitting to deal with.  I'm back to steel work both inside and out.

Just another quick question if I may.  Assuming the skin tank is  serviceable would you consider it large enough to provide keel cooling?

The area you circled had a large patch of clear sealant stuck to the side but it doesn't hide anything sinister.🙂

[Tony Brooks]

7 minutes ago, Rufus1010 said:

Just another quick question if I may.  Assuming the skin tank is  serviceable would you consider it large enough to provide keel cooling?

 

If it is close to 9 sq ft on one side and baffled then yes, if not it is likely to boil on rivers.

 

There are two forms of raw water cooling. Direct where the raw water passes through the engine, and indirect that uses a heat exchanger in the manifold.

 

The pair of rubber clips around the rubber boots on each end of the manifold, plus the large hose connecting manifold and thermostat housing suggests that you have a heat exchanger core inside the manifold (be aware they can block with raw water debris)

 

What I can't be sure of is the return from the manifold cum heat exchanger into the ENGINE water pump (not the raw water pump).

[Bee]

That has got a bit of everything. I wonder if its had a selection of engines over the years. each one with a different cooling system. Does it run? Does it run OK? I think I would try and settle on keel cooling and make it work. You might well find that the keel cooling tank leaks but if you are having welding done then that makes it easier to repair. Raw water (or heat exchanger) cooling should have a decent sea cock that should be off when you leave the boat and a syphon break to stop water syphoning back to the engine and a different exhaust system to be safe. Oh and a water strainer or weed filter of some sort otherwise the system will fill up with weed, shrimps and wriggly things.

Edited June 17, 2023 by Bee

[Tony Brooks]

11 minutes ago, Bee said:

That has got a bit of everything. I wonder if its had a selection of engines over the years. each one with a different cooling system. Does it run? Does it run OK? I think I would try and settle on keel cooling and make it work. You might well find that the keel cooling tank leaks but if you are having welding done then that makes it easier to repair. Raw water (or heat exchanger) cooling should have a decent sea cock that should be off when you leave the boat and a syphon break to stop water syphoning back to the engine and a different exhaust system to be safe. Oh and a water strainer or weed filter of some sort otherwise the system will fill up with weed, shrimps and wriggly things.

 

No Bee, it does not need a different exhaust because the waste raw water can go straight through the hull. In fact, trying to use a wet exhaust as that one is laid out is likely to end in expensive tears because of the potential for hydro-locking you clearly know about.

 

I fully agree with using the skin tank for a canal boat if possible.

[Rufus1010]

Thanks all, I've already learned so much in a day and a half!  When the engine is out I'm going to do a partial strip to see if it's viable, if not it will be replaced. I've removed the hoses from the manifold today and there is indeed a heat exchanger core (very gunked up!)

This project will be a lengthy one but will be completed. I will undoubtedly be back with more questions, if I become a pain just say.....I won't be offended.🙂