Calorifier pump?

[Janz]

Hi guys,

What is this? Is it a pump that feeds the calorifier? I have bought a boat with the calorifier disconnected. There are two hoses on it that should be plumbed into the engine but no obvious inlet/exit fittings.

This pump must have been disconnected/blanked off as it is leaking, both from the shaft & the gasket. It's also been packed with grease, presumablyto negate the leak but it ain't cutting it. When the engine is running, it starts losing a lot of water & I can't really sort out the rest of the cooling system &/or add antifreeze until it is either watertight or swapped out for something that works. In order to fix it I would need to know brand, model & function. I'm good for air cooled motorbike engines but I don't know much about water cooling stuff such as cars, boats etc...

Any ideas?

[Janz]

The belt is also on its last legs, so to get one I need a model name/number. Is it part of the Bowman thing adjacent to the rocker box?

Could someone point me to a thread on what that does & its connections?

My tub is using a closed cooling system like a car with skin tanks for rads. It's ok for now but if the temperature droms I'm worried it might freeze as I'm just running straight water through it...

[Tony Brooks]

That is nothing to do with the calorifier or if it has it is a  very odd system and the domestic hot water probably stays veyy cool.

 

It is (normally) the raw water pump that pumps river/canal water through the heat exchanger core to act like the air through a car radiator to cool the engine coolant.

 

Basically the pump body has worn so you now need a new pump (£100s probably) but there is a packed gland under the big nut behind the pulley so you could try repacking that and seeing how it goes. If it works this could turn out to be  a very  frequent job. A new pump may look different to this one. I expect sleeving the body and a new shaft would cost more than a new pump.

[Jen-in-Wellies]

Welcome to the forum. What you have there is a raw water pump for the cooling system. Nothing to do with the calorifier at all. It is part of the engine cooling system. Takes water from the canal, passes it through a heat exchanger with the engine coolant and then dumps it in to the engine exhaust. It needs to work, or your engine will overheat and die. The grease filled things are to lubricate the bearings each side of the pump.

 

[Tony Brooks]

Just now, Janz said:

The belt is also on its last legs, so to get one I need a model name/number. Is it part of the Bowman thing adjacent to the rocker box?

Could someone point me to a thread on what that does & its connections?

My tub is using a closed cooling system like a car with skin tanks for rads. It's ok for now but if the temperature droms I'm worried it might freeze as I'm just running straight water through it...

 

he stuff you ask about is in the maintenance notes on http://www.tb-training.co.uk. I very much doubt that you have a skin tank so photos of the entire area showing where the pipe & hoses go.

[Janz]

Wow, thanks for the prompt replies! Excellent... ok, what I don't get is why I have two cooling systems. Why use raw canal water & also have a header tank & two skin tanks?

[Janz]

6 minutes ago, Tony Brooks said:

 

he stuff you ask about is in the maintenance notes on http://www.tb-training.co.uk. I very much doubt that you have a skin tank so photos of the entire area showing where the pipe & hoses go.

Thanks Tony.

I will head down there & take some pics.

But from memory the header tank runs to a welded in tank which is about 40 litres capacity. A hose exits the bottom of the tank & runs across the prop shaft to another identical tank on the other side with an air bleed on it. A thick hose then exits, runs along the bulkhead but I haven't looked where that goes...

[MtB]

22 minutes ago, Janz said:

Wow, thanks for the prompt replies! Excellent... ok, what I don't get is why I have two cooling systems. Why use raw canal water & also have a header tank & two skin tanks?

 

Probably because an idiot designed and installed it, or your boat has had an engine change. 

 

Photos of the pump only tell half the story. You need to follow the pipes connected to the pump and see/tell the forum where they come from/go to, to get a fuller understanding of what is going on. 

Edited February 8, 2022 by MtB

[Tony Brooks]

Right that sounds like a hybrid system (or a bit of a bodge) where what would normally be canal/river (raw) water is replaced by another header tank that has antifreeze mixture in it. This mixture is probably pumped through the heat exchager core to cool the engine coolant, then through the skin tanks to get rid of the heat it has absorbed and back, cool, to the pump.

 

This means there is probably two fillers, one on the "raw water" header thank and one on the manifold/heat exchange for the engine coolant.

 

If the connections on the skin tanks is in excess of 1" ID then that pump could be done away with by re plumbing  to just use the engine water pump.

[Janz]

4 minutes ago, MtB said:

 

Probably because an idiot designed and installed it, or your boat has had an engine change. 

 

Photos of the pump only tell half the story. You need to follow the pipes connected to the pump and see/tell the forum where they come from/go to, to get a fuller understanding of what is going on. 

Thanks 👍, my boat is old (1981), so that could be likely. It's a BMC 1500 D. I'm heading down now to take pics. I'll give the pump a regrease whilst there & report back asap...

[Tony Brooks]

3 minutes ago, MtB said:

 

Probably because an idiot designed and installed it, or your boat has had an engine change. 

 

Photos of the pump only tell half the story. You need to follow the pipes connected to the pump and see/tell the forum where they come from/go to, to get a fuller understanding of what is going on. 

 

You can see the pump feeds into the manifold but I can't see how many clips are on the rubber end cap so can't confirm there is a heat exchanger core inside. I can also see the return from the heat exchanger going by large bore pipe back into the engine water pump. If there is no heat exchange core then it is an even bigger bodge that I think it is. We must await more photos, especially of the rubber end caps on the manifold.

[Janz]

There are two fillers as you described. The header tank one is the supply that is losing water...

37 minutes ago, Jen-in-Wellies said:

Welcome to the forum. What you have there is a raw water pump for the cooling system. Nothing to do with the calorifier at all. It is part of the engine cooling system. Takes water from the canal, passes it through a heat exchanger with the engine coolant and then dumps it in to the engine exhaust. It needs to work, or your engine will overheat and die. The grease filled things are to lubricate the bearings each side of the pump.

 

Thanks 👍I shall regrease it & see if it slows the leak. I have never seen any water coming from the exhaust no matter what the conditions - full, empty, bled or unbled...

[Tony Brooks]

4 minutes ago, Janz said:

I have never seen any water coming from the exhaust

 

That confirms its a bodge system.

[MtB]

2 minutes ago, Janz said:

Thanks 👍, my boat is old (1981), so that could be likely.

 

Just to clarify, I wasn't meaning to run down your boat in particular, rather to point out NBs especially older ones, sometimes have engine installations carried out by amateurs doing their first and only install, which consequently contain some right howlers. I think you said you only just bought it and people new to boating often expect boats to be like cars, i.e. very carefully designed and developed and generally 'right'. This is not the case. It is very much a cottage industry where production runs are often limited to single or double figures and by people making it up as they go along. Bear this in mind! 

[Janz]

5 minutes ago, Tony Brooks said:

 

You can see the pump feeds into the manifold but I can't see how many clips are on the rubber end cap so can't confirm there is a heat exchanger core inside. I can also see the return from the heat exchanger going by large bore pipe back into the engine water pump. If there is no heat exchange core then it is an even bigger bodge that I think it is. We must await more photos, especially of the rubber end caps on the manifold.

Thanks, I have just read the maintenence link to your site. I shall try & replumb the calorifier when I know what the hell is going on with the cooling system. It's a steep learning curve, this... normally, if I see water coming from an exhaust pipe, I get scared. Now I'm getting scared if I don't..!

[Tony Brooks]

1 minute ago, Janz said:

Thanks, I have just read the maintenence link to your site. I shall try & replumb the calorifier when I know what the hell is going on with the cooling system. It's a steep learning curve, this... normally, if I see water coming from an exhaust pipe, I get scared. Now I'm getting scared if I don't..!

 

The engine looks like a BMC 1.5 so the calorifier take of is on top of the head, probably a choice of hexagon plug at either end. The return goes into the return to the ENGINE (big pulley) water pump.

 

I am 99% certain there should be no  water coming from the exhaust.

[Janz]

4 minutes ago, MtB said:

 

Just to clarify, I wasn't meaning to run down your boat in particular, rather to point out NBs especially older ones, sometimes have engine installations carried out by amateurs doing their first and only install, which consequently contain some right howlers. I think you said you only just bought it and people new to boating often expect boats to be like cars, i.e. very carefully designed and developed and generally 'right'. This is not the case. It is very much a cottage industry where production runs are often limited to single or double figures and by people making it up as they go along. Bear this in mind! 

😂 loool, it's cool, you can run down my boat if you want, it's a shed. It's basically a floating building site. I ran it down to London from Herts but I kept topping up with water to keep it under 100°C. When fully topped up it runs around 70-80°C. Hasn't let me down yet. I did all the tappets halfway & I need to change the oil but the oil pump thing doesn't pump... the gasket is worn out & doesn't touch the sides. It smokes a bit, especially on start up but doesn't lose oil & there's no water in the oil. I dunno whether there's oil in the water because the water doesn't hang around long enough to see any.

From the index number search, the boat was originally made by 'Tollandine' in 1981 & it's 39'6". I don't know whether that helps in pinning down whether it's had an engine swap. 👍

[Tony Brooks]

3 minutes ago, Janz said:

the oil pump thing doesn't pump... the gasket is worn out & doesn't touch the sides.

 

Are you sure, have you unscrews the top to look inside. What often happens is the bottom unscrews from the piston so the seal falls off and the piston valve ball and spring falls out. The hardest thing about putting it right is getting the bits out.  I used to take the pump off and tip them into a tray.

[Janz]

No it's all there Tony, the 'piston ring' thing is totally knackered - it's rock hard & cracked. I felt around the sump but there's no sump plug, so I think it's a bespoke marinised engine. I need to buy a rubber hand pump from ebay or see if my pal has an old beer pump in his shed to get the old oil out or maybe a replacement for the piston can be sourced. I shall take a bunch of pics in a bit. The tub is only a mile away near lock 100 in Brentford so I wont be long.

Thanks for your replies guys. This forum is most efficient, well done. You have put my mind at rest quite a lot. Just knowing that there's sound advice available is a great help. Bless you all...

[Tracy D'arth]

Is it a cast ally sump or a tin one? If the latter, is it the same depth all along or shallow at the front half? If its the original tin sump the plug is not on the bottom but on the cross wise corner of the deep part.

[Janz]

3 hours ago, Tracy D'arth said:

Is it a cast ally sump or a tin one? If the latter, is it the same depth all along or shallow at the front half? If its the original tin sump the plug is not on the bottom but on the cross wise corner of the deep part.

I'm there now. Gonna have a look 👍

[Janz]

 

  Ok guys.

My bad, I got it wrong, the plumbing is as follows:

From the header tank, the water flows directly to the port side skin tank. From there it goes to the lower part of the pump, then into the heat exchanger, out the other side & into the top of the second skin tank, out of the bottom of that through a two inch hose & it looks like it goes out of the side of the boat but I can't see where.

 

There are two jubilee clips on each end of the heat exchanger...

A pal just had a look & he's as bemused as I am as to why it's like it is. I'm going to post up some pics as soon as I resize them.

👍

[Janz]

[Tony Brooks]

The hose clip in the middle of the rubber end cap implies there is a heat exchanger core inside it.

 

I can't make out the pipe run you describe. It needs a return pipe from the second skin tank (the 2" one) back to the header tank or first skin tank, otherwise you can't circulate the liquid.

 

It is very unusual to put the heat exchanger core between the two skin tanks, but it is still using both tanks to cool. Normally the pipework would be something like filler pipe from that header tank to one skin tank. Then ignoring that roughly 1/2" to 5/8" bore pipes/hoses from one skin tank bottom connection to top connection of the other. Then bottom connection of that tank to the Jabsco pump inlet. From Jabsco pump outlet to one rubber end cap of the  manifold and then from the other end cap into the top of the first skin tank.

 

In that way the hotter water enters the top of the tank and then drops as it cools and gets denser, only after it has passed through both tanks does it return to Jabsco pump to be recirculated.

 

I wonder if those totally stupid and poorly designed skin tanks has necessitated the fitting of an external tank or pipe loop to augment the cooling capacity. Skin tanks should be very thin but cover a large area. In your case a bit shy of 9 sq ft but only about half to one inch thick. For just canal work you could get away with a smaller skin tank but it might boil on rivers and tideways. You need to find the way the second tank connects back to the pump.

 

[David Mack]

47 minutes ago, Janz said:

My bad, I got it wrong, the plumbing is as follows:

From the header tank, the water flows directly to the port side skin tank. From there it goes to the lower part of the pump, then into the heat exchanger, out the other side & into the top of the second skin tank, out of the bottom of that through a two inch hose & it looks like it goes out of the side of the boat but I can't see where.

I would expect the hose from the bottom of the second tank to go to the top of the first tank - possibly at the opposite end to the header tank and bottom connections. That way you have a complete circuit flowing from top to bottom through both skin tanks, then through the pump and heat exchanger. The header tank is only there to supply a small quantity of make-up water to cover for any leakage, and to accommodate water pushed out of the main circuit as the engine warms up and the coolant expands.