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What’s a land? 

35 minutes ago, Tony Brooks said:

 

I agree but would he get enough wrap on the new pump pulley? Just a thought. I think this may be the easiest way of doing it. Otherwise as even a large Jabsco pump takes a comparatively modest load I think those three allen screws could be used to drive an extra crankshaft pulley without issue. It would need a land to centralise it on the existing pulley I suspect. seeing the size of the crankshaft pulley on the 1.5s with a Jabsco pump (very small) I don't think here would be much load at all

 

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1 hour ago, Pierre Thomas said:

What’s a land? 

 

 A land is a piece of a stricture that stick out, usually related to locating something, so in this case it would be a sticky out bit that fits the hole in the middle of the multi-groove pulley so it has to be central and run true.

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47 minutes ago, Pierre Thomas said:

I’m struggling to find a 12V electric pump that will shift the same amount of water. 

 

How much do you need ?

 

I've recently bought an electric pump yo use as a 'roving bilge pump' which is around 35-45 litres per minutre depending on head.

 

12V PORTABLE ELECTRIC FUEL DIESEL FLUIDS TRANSFER PUMP CLIP ON BATTERY | eBay

 

Problem is that it draws 10 amps, so you'll need an extra battery, just for the pump, and obviously a means of putting (say) 60Ah per day back in (5 hours @ 10amps + inefficiencies)

 

 

 

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9 hours ago, Alan de Enfield said:

 

How much do you need ?

 

I've recently bought an electric pump yo use as a 'roving bilge pump' which is around 35-45 litres per minutre depending on head.

 

12V PORTABLE ELECTRIC FUEL DIESEL FLUIDS TRANSFER PUMP CLIP ON BATTERY | eBay

 

Problem is that it draws 10 amps, so you'll need an extra battery, just for the pump, and obviously a means of putting (say) 60Ah per day back in (5 hours @ 10amps + inefficiencies)

The other problem is that it won't be continuously rated, and uses a brushless motor so the service life will probably be in the hundreds of hours. 

 

Lots of cars use electric water pumps now, to supplement the engine driven one for intercooler or heater circuits. They're not cheap but are brushless, high flow and have a long service life as there's no mechanical seal on the shaft between pump and motor - it's magnetically driven. Most common one is the Bosch PAD12V but there's plenty of other options with higher flow and different output spigot sizes. As the pump has a built-in RPM sensor similar to brushless motors in computer fans, it can be used with a compatible controller to give a low RPM alarm...and the fancier controllers can also ramp up/down the pump speed at specific temperatures or run it on a timer after the engine's been turned off.

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10 hours ago, Tracy D'arth said:

 

Is only a small improvement on what I've got which is inadequate at 30plm, The one indicated in an earlier post is  158 lpm or a factor more. 
I can see alternator capacity being an issue with an electric pump.

The other factor is that no matter how fast the engine goes (or how hard it is working) an electric pump is constant.

It's an intercooler pump I'm using at the moment. I shall look through the Craig-Davies pumps.

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40 minutes ago, Pierre Thomas said:

 

Is only a small improvement on what I've got which is inadequate at 30plm, The one indicated in an earlier post is  158 lpm or a factor more. 
I can see alternator capacity being an issue with an electric pump.

The other factor is that no matter how fast the engine goes (or how hard it is working) an electric pump is constant.

It's an intercooler pump I'm using at the moment. I shall look through the Craig-Davies pumps.

 

Mine has a gear-wheel & actually connects to the drive for the air brake compressor.

You can see from the drawing that it has a tapered shaft to which any manner of 'drive' options can be fitted (Gear wheel, pulley, PTO shaft fitting etc etc)

 

The Triangular lobed bracket gives you a menas of mounting it, but I have seen ones with a flat "L" bracket which attaches to the pump, and then mounts flat onto the engine and is then pulley driven.

 

They are all the same pump (F7B) but the added "-?" is the fitting/drive method. MIne is "-9", the foot mounted one is "-8"

 

Products tagged "Johnson F7B-5000 1" BSP Horizontal Impeller Pump without  Clutch" - The Wetworks

 

 

 

 

The F7B-8 has fixing feet and can have a pulley mounted :

 

 

 

SPX Johnson Heavy Duty Impeller Pump 1" F7B-8 10-24572-01

 

Johnson_10-24139-4_parts.jpg

Screenshot (659).png

Edited by Alan de Enfield
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2 hours ago, Pierre Thomas said:

 

Is only a small improvement on what I've got which is inadequate at 30plm, The one indicated in an earlier post is  158 lpm or a factor more. 
I can see alternator capacity being an issue with an electric pump.

The other factor is that no matter how fast the engine goes (or how hard it is working) an electric pump is constant.

It's an intercooler pump I'm using at the moment. I shall look through the Craig-Davies pumps.

158 Lpm is hell of a flow rate, that is what you get from a mains submersible pump.

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2 hours ago, Pierre Thomas said:

 

Is only a small improvement on what I've got which is inadequate at 30plm, The one indicated in an earlier post is  158 lpm or a factor more. 
I can see alternator capacity being an issue with an electric pump.

The other factor is that no matter how fast the engine goes (or how hard it is working) an electric pump is constant.

It's an intercooler pump I'm using at the moment. I shall look through the Craig-Davies pumps.

The litres per minute assumes that there's no restriction on the output - depending on the pump, the flow will drop in different proportion to the pressure. Davies Craig publish theirs, can you compare it against your current pump? https://daviescraig.com.au/electric-water-pumps near the bottom.

 

I've got a feeling the flow rate of the existing intercooler pump isn't much under pressure.

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2 minutes ago, ditchcrawler said:

158 Lpm is hell of a flow rate, that is what you get from a mains submersible pump.

It's down as 107 lpm on the Johnson spec for the F7B-8, my existing one is 30lpm  but does no more than trickle even though all the pipes are 1" bore.

 

But as Cheesegas says, pressure make a difference

6 minutes ago, cheesegas said:

The litres per minute assumes that there's no restriction on the output - depending on the pump, the flow will drop in different proportion to the pressure. Davies Craig publish theirs, can you compare it against your current pump? https://daviescraig.com.au/electric-water-pumps near the bottom.

 

I've got a feeling the flow rate of the existing intercooler pump isn't much under pressure.

 

It's very irritating, nowhere does it mention current or 12V power needed.

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5 minutes ago, Pierre Thomas said:

It's very irritating, nowhere does it mention current or 12V power needed.

Their site isn't very good, you need to go into the Products page, select a pump and then click Downloads to get the spec sheet. Looks like it's around 7-10 amps depending on backpressure.

https://daviescraig.com.au/media/694/1427092566.EWPSelectionGuideTechSpecs2009.pdf

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12 minutes ago, cheesegas said:

Their site isn't very good, you need to go into the Products page, select a pump and then click Downloads to get the spec sheet. Looks like it's around 7-10 amps depending on backpressure.

https://daviescraig.com.au/media/694/1427092566.EWPSelectionGuideTechSpecs2009.pdf

 

I'm quite liking the EWP150 with the controller. 10A is not too much for the engine alternator and the mounting would fit nicely with the existing plumbing. 

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19 minutes ago, Mike Tee said:

Slightly off-topic but still skin tank related - does anyone know if a skin tank has ever been successfully fitted to a vintage iron sided ex-working boat (apologies in advance to the vintage purists)

No doubt it could be done, but it is much more fiddly with the need to fit the plates around the knees and chine angle, avoid rivets, avoid heat damage to rivets, which might cause them to leak, as well as the issues of welding steel to iron. 

But a few working boats have fitted a 'trombone' i.e. a loop of pipe outside the hull, under the counter, to achieve the same effect.

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8 minutes ago, Mike Tee said:

Slightly off-topic but still skin tank related - does anyone know if a skin tank has ever been successfully fitted to a vintage iron sided ex-working boat (apologies in advance to the vintage purists)

I personally don't know of any but there must be many, especially the ones with a new stern and counter. its all those riveted seams and things that would be a headache. Heat exchanger cooling using canal water would be easier or even external cooling pipes if they could be squeezed in.  Its always struck me how inefficient keel cooling tanks are. I have a Beta 43 with a heat exchanger, the innards of that exchanger are the size of a couple of baked bean cans full of tubes with  canal water flowing through them.  The exhaust and water that comes out of the side of the boat is comfortably warm, if that  engine was keel cooled it would need a great big slab of a thing welded to the boat and there's every chance it would still be too small or barely big enough. Odd.

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8 minutes ago, Bee said:

Its always struck me how inefficient keel cooling tanks are. I have a Beta 43 with a heat exchanger, the innards of that exchanger are the size of a couple of baked bean cans full of tubes with  canal water flowing through them.  The exhaust and water that comes out of the side of the boat is comfortably warm, if that  engine was keel cooled it would need a great big slab of a thing welded to the boat and there's every chance it would still be too small or barely big enough. Odd.

But the skin tank is trying to push that heat through 6mm of steel plus a few coats of blacking, whereas in the heat exchanger it is less than a millimetre of brass.

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1 hour ago, ditchcrawler said:

158 Lpm is hell of a flow rate, that is what you get from a mains submersible pump.

 

It what is quoted for my Johnson 1" engine cooling 'fresh water' pump. The OP has picked it up from there, althoughhe asked for details on 'bigger Lpm pumps -  I did explain it is a bit bigger engine that his.

 

It is rated at 2100 gallons an hour / 35 gallons per minute / 158 litres per minute, at 3000rpm.

 

Edit to add flow rate graph.

Screenshot (661).png

Edited by Alan de Enfield
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40 minutes ago, Bee said:

The exhaust and water that comes out of the side of the boat is comfortably warm, if that  engine was keel cooled it would need a great big slab of a thing welded to the boat and there's every chance it would still be too small or barely big enough. Odd

 

Raw water cooled has an effectively unlimited supply of cold water if it doesn't block.  A skin tank needs to be big enough to allow the water to cool down before it gets recirculated.

 

The heat will transfer much faster on the engine because of the temperature difference.  40 to 70 degrees gradient on the engine, maybe 5 or 10 degrees at the skin tank.

 

If you want to see the difference, stick a hose between your raw water outlet and inlet and see how long it takes your engine to overheat.  

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2 minutes ago, TheBiscuits said:

If you want to see the difference, stick a hose between your raw water outlet and inlet and see how long it takes your engine to overheat.  

 

Or, as happened this Summer, the outlet pipe from the pump comes 'adrift' within seconds you have 1000 litres+ (and increasing rapidly) of water in the bilges and within a couple of minutes the engine is a mass of steam and will not survive much longer.

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6 minutes ago, Alan de Enfield said:

 

Or, as happened this Summer, the outlet pipe from the pump comes 'adrift' within seconds you have 1000 litres+ (and increasing rapidly) of water in the bilges and within a couple of minutes the engine is a mass of steam and will not survive much longer.

 

Yes, but I don't recommend trying that!

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1 hour ago, Mike Tee said:

Thanks for the comments - my meanderings were directed at ending up with a calorifier for onboard hot water. Probably hugely expensive for not a huge improvement!

 

I think that you have a heat exchanger (indirect raw water) cooled engine and those are usually more than capable of running a calorifier and it would also tend keep the engine cooler while the calorifier heats up.

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