Skin tank size?

[NB Alnwick]

Perhaps you could fit a car type fan cooled radiator matrix to which you could divert cooling water through when needed?

 

That would be a bit complicated but we have considered plumbing a traditional central heating style radiator (located in the 'airing cupboard') into the cooling system or even fitting an additional skin tank.

[nb Innisfree]

That would be a bit complicated but we have considered plumbing a traditional central heating style radiator (located in the 'airing cupboard') into the cooling system or even fitting an additional skin tank.

 

Prob with CH rad is rusting due to mild steel construction.

 

Sorry ignore that, I mistakenly thought you had direct cooling. Yes a Ch rad would be fine

Edited June 7, 2009 by nb Innisfree

[Guest]

Prob with CH rad is rusting due to mild steel construction.

Interesting thought. I have a domestic radiator on the engine cooling circuit, which works wonders. I wondered about corrosion, but then the skin tank is mild steel. Do they corrode? Does antifreeze act as a corrosion inhibitor?

 

Edit: Just saw your edit.

Edited June 7, 2009 by Guest

[david and julie]

Does antifreeze act as a corrosion inhibitor?

Yes.

[NB Alnwick]

Interesting thought. I have a domestic radiator on the engine cooling circuit, which works wonders. I wondered about corrosion, but then the skin tank is mild steel. Do they corrode? Does antifreeze act as a corrosion inhibitor?

 

Edit: Just saw your edit.

 

I have issues with the use of Ethylene Glycol as an 'anti-freeze' in marine engines. This is an extremely toxic substance and unlike engine oil which can be recycled it is difficult to dispose of. I know of at least one case where a boater flushed his used anti-freeze (gallons of it) into the canal which means that (apart from the effect it will have had on fish and other creatures living in and around the canals) it could, eventually, find its way into the national fresh water supply.

 

I prefer to use less toxic corrosion inhibitors and prevent my engine from freezing by maintaining an ambient temperature of at least 40^o Fahrenheit in the engine room.

[sueb]

We had cooling probs with a large skin tank but no baffles. We went to Kevin @ Winkwell who put a thin skin tank on the outside of the swim. He built in baffles and we have had no probs since with cooling and it didn't alter the handling.

Sue

[alan_fincher]

We had cooling probs with a large skin tank but no baffles. We went to Kevin @ Winkwell who put a thin skin tank on the outside of the swim. He built in baffles and we have had no probs since with cooling and it didn't alter the handling.

Sue

Yes, I agree with this - been there - done that.

 

If you need to add a new skin tank to an existing boat, and avoid 90% of the possible grief, put it on the outside, and keep it thin. It must have baffles!

[Chertsey]

The obvious answer is to enhance the cooling tank capacity but this would then result in overcooling on canals.

 

 

Since most proper marine engines were originally designed for raw water cooling - something else that is impractical on modern canals due to the large quantity of plastic bags and similar detritus that now floats around

 

I may be being thick here, but how could an engine designed to be raw water cooled be over-cooled using a skin tank?

[NB Alnwick]

I may be being thick here, but how could an engine designed to be raw water cooled be over-cooled using a skin tank?

 

You are not the only person who has pointed this out - on the balance of authoritive opinion, I must accept that the 'overcooling bit' is nonsense. As one contributor pointed out it may be a story propagated by boat builders to justify inadequately sized skin tanks.

[Tony Brooks]

I may be being thick here, but how could an engine designed to be raw water cooled be over-cooled using a skin tank?

 

Well, there is one way, but its nothing to do with the skin tank, its just that using a smaller skin tank may have covered up over cooling.

 

Some direct cooled engines, often those based on automotive units, tended to fur up the hotspots I talked about earlier in this thread. A cheap and simple way out of this was to throw away the thermostat so the engine spend most of its time with a much larger than designed temperature difference between the coolant and the hotspots. If/when this engine was bought secondhand and installed on a skin tank system where furring the hotspots would be at a very much slower rate a smaller tank would rise the running temperature - until it boiled.

 

This would also be true for any engine that was never designed to employ a thermostat, possibly like a tank cooled early industrial engine and the propensity for some narrowboat owners to fit ancient engines would tend to suggest this may be where the over-cooling thing originated.

[ronie]

Hi,

 

Just want to say thanks for everyone who has taken the time to reply - it is much appreciated!

 

looks like we are going to be needing a new skin tank - and as we don't have a lot of money, making it ourselves (gulp!)

 

Any suggestions as to how to connect two tanks up? And does anyone know a good place to buy fittings for the skin tank?

 

As far as I know it only needs one baffle is that right? Anyone done one and have any tips as to the best way to tackle it?

 

Should add we are not professional welders so simple is the way to go!

 

Thanks

 

Ronie

[Tony Brooks]

Hi,

 

Just want to say thanks for everyone who has taken the time to reply - it is much appreciated!

 

looks like we are going to be needing a new skin tank - and as we don't have a lot of money, making it ourselves (gulp!)

 

Any suggestions as to how to connect two tanks up? And does anyone know a good place to buy fittings for the skin tank?

 

As far as I know it only needs one baffle is that right? Anyone done one and have any tips as to the best way to tackle it?

 

Should add we are not professional welders so simple is the way to go!

 

Thanks

 

Ronie

 

In that case think about something like 1" steel pipe & U fittings formed into a sort of double Z and fitted outside the swim. You can do this with standard plumbers iron fittings and only tack weld it to the hull. I think I would pay a welder to run a bead around each through swim pipe to ensure its watertight.

[NB Alnwick]

Well, there is one way, but its nothing to do with the skin tank, its just that using a smaller skin tank may have covered up over cooling.

 

Some direct cooled engines, often those based on automotive units, tended to fur up the hotspots I talked about earlier in this thread. A cheap and simple way out of this was to throw away the thermostat so the engine spend most of its time with a much larger than designed temperature difference between the coolant and the hotspots. If/when this engine was bought secondhand and installed on a skin tank system where furring the hotspots would be at a very much slower rate a smaller tank would rise the running temperature - until it boiled.

 

This would also be true for any engine that was never designed to employ a thermostat, possibly like a tank cooled early industrial engine and the propensity for some narrowboat owners to fit ancient engines would tend to suggest this may be where the over-cooling thing originated.

 

Perhaps I am being over-sensitive but if this is intended to be a reference to the Kelvin 'K' and 'J' series engines, it may be worth pointing out that, from a design point of view, they are at least as modern as (and probably superior in build quality to) the ancient example that Tony Brooks was using for his demonstration at Crick. Similarly, the RN engines which are still in production are far better suited for narrow boat purposes than the modified taxi engines that are so often used purely on the grounds of cost.

[alan_fincher]

Similarly, the RN engines which are still in production are far better suited for narrow boat purposes than the modified taxi engines that are so often used purely on the grounds of cost.

Being pedantic, but people often state that taxi engines are regularly marinised for narrowboats.

 

So far as I'm aware the diesels used in the classic FX4 London cab were either the BMC 2.2, or the BMC 2.5.

 

Whilst these are occasionally seen in narrowboats, you could hardly say "often used", as really they are really quite rare, (and people with them seem not to know what they have, quite often )

 

Like so many of the "vintage" or "enthusiasts" engines often shoe-horned into narrowboats, the taxi engines are frankly more powerful than most pleasure narrowboaters would need.

 

What I suspect you are referring to are the 1.5 and 1.8 BMCs - a different engine altogether, and as far as I know, not a taxi engine.

 

I'm guessing that Tony would consider something like an RN a very suitable boat engine - it is of course. But its (I think) 18HP used to happily push two fully loaded narrowboats along. Compare that to some of the ton and a half lumps producing three times the horsepower, and required to do nothing more than push a Hudson pleasure boat along. It's hard to argue that's a more appropriate engine than a BMC in a mid-range shell, surely ?

 

I guess which is "far better suited for narrow boat purposes" depends on how much of your time you like to explore finding out where the bottom of the cut is, and how much of it you like to spend making good progress.

Edited June 10, 2009 by alan_fincher

[churchward]

Being pedantic, but people often state that taxi engines are regularly marinised for narrowboats.

 

So far as I'm aware the diesels used in the classic FX4 London cab were either the BMC 2.2, or the BMC 2.5.

 

Whilst these are occasionally seen in narrowboats, you could hardly say "often used", as really they are really quite rare, (and people with them seem not to know what they have, quite often )

 

Like so many of the "vintage" or "enthusiasts" engines often shoe-horned into narrowboats, the taxi engines are frankly more powerful than most pleasure narrowboaters would need.

 

What I suspect you are referring to are the 1.5 and 1.8 BMCs - a different engine altogether, and as far as I know, not a taxi engine.

 

I'm guessing that Tony would consider something like an RN a very suitable boat engine - it is of course. But its (I think) 18HP used to happily push two fully loaded narrowboats along. Compare that to some of the ton and a half lumps producing three times the horsepower, and required to do nothing more than push a Hudson pleasure boat along. It's hard to argue that's a more appropriate engine than a BMC in a mid-range shell, surely ?

 

I guess which is "far better suited for narrow boat purposes" depends on how much of your time you like to explore finding out where the bottom of the cut is, and how much of it you like to spend making good progress.

Actually it may soon be time to consider the BMC 1.5 and 1.8 as a "vintage" engine given it's longevity and origins or indeed as a "traditional" narrowboat (pleasure) lump as so many have used them over a long period of time now.

 

Perhaps I am being over-sensitive but if this is intended to be a reference to the Kelvin 'K' and 'J' series engines, it may be worth pointing out that, from a design point of view, they are at least as modern as (and probably superior in build quality to) the ancient example that Tony Brooks was using for his demonstration at Crick. Similarly, the RN engines which are still in production are far better suited for narrow boat purposes than the modified taxi engines that are so often used purely on the grounds of cost.

Yes I think you are given your earlier rather sniffy post about buzzing modern engines and egg whisks!

 

Other than making the canals a playground for the rich I see no practical way that all canal boats could use "proper" vintage marine engines. There aren't enough to go around for a start and cost is a factor for many people. Not everyone is going to afford £16K for a refurbished RN or indeed over £20K for a new one.

[alan_fincher]

Yes I think you are given your earlier rather sniffy post about buzzing modern engines and egg whisks!

 

Other than making the canals a playground for the rich I see no practical way that all canal boats could use "proper" vintage marine engines. There aren't enough to go around for a start and cost is a factor for many people. Not everyone is going to afford £16K for a refurbished RN or indeed over £20K for a new one.

Hear, hear....

 

The same thought has been repeatedly going through my mind each time people tell us that the only proper narrow boat engine are the huge slow running lumps running twenty-something inch props in shells that claim to replicate working boats, (but frankly often do not).

 

Such attitudes seem unnecessarily elitist, because, as Churchward says, the only way it could be achieved is by only having as many boats as there were available and affordable "proper" engines, (and hence kicking the majority of existing boaters off the system).

 

Even if you could manufacture enough "suitable" engines and shells, and assuming everybody could afford them, the canals would then become grid-locked as everybody was out there trying to push their way through the shallows.

 

Can I also nominate the Lister SR engines as truly vintage. Far, far, more of these were original fit in (admittedly leisure) narrowboats, than any of the bigger lumps claiming the status of "narrowboat" engine.

 

Finally, I also thought the "buzzing engine" and "egg whisk" thing unnecessary. There seems to be an assumption that those with more modest boats are not extracting as much pleasure from them as those who have a fortune to spend. Getting out and about by boat regularly, and meeting boat owners, I think it's a totally flawed assumption, TBH.

 

(Edited for spelling)

Edited June 10, 2009 by alan_fincher

[RLWP]

Finally, I also thought the "buzzing engine" and "egg whisk" thing unnecessary. There seems to be an assumption that those with more modest boats are not extracting as much pleasure from them as those who have a fortune to spend. Getting out and about by boat regularly, and meeting boat owners, I think it's a totally flawed assumption, TBH.

 

(Edited for spelling)

 

I can assure you that we extracted loads of pleasure on the BCN challenge by having a shallow draught and an accessible weedhatch. Much better than having to call BW to get us through a bridge hole, not getting to the end of the Bradley Arm or fishing about after lengths of plastic with a boathook.

 

Richard

 

1' 10" draught, BMC 1.8, cruiser stern.

[Tony Brooks]

Perhaps I am being over-sensitive but if this is intended to be a reference to the Kelvin 'K' and 'J' series engines, it may be worth pointing out that, from a design point of view, they are at least as modern as (and probably superior in build quality to) the ancient example that Tony Brooks was using for his demonstration at Crick. Similarly, the RN engines which are still in production are far better suited for narrow boat purposes than the modified taxi engines that are so often used purely on the grounds of cost.

 

The engines I am referring to are those of any make that were designed for industrial use, have often been recovered from all sorts of odd places and then "marinised" and sold on. When I say tank cooled I do not mean skin tank cooled but the system that places a tank of water above the engine and it circulates either by convection or maybe a pump. You can see them steaming away and most steam events down one end of the field.

 

I believe the Kelvin was available as a marine unit from new as were RNs.

 

Just because an engine is nice and shiny and it is sold as a marine unit does not mean that it is one or it will be satisfactory. In any case I was not denigrating old engines in the generality, just those of a certain type (not make) that have had insufficient thought and knowledge put into their marinisation. Those can be overcooled by fitting a larger skin tank.

[NB Alnwick]

Being pedantic, but people often state that taxi engines are regularly marinised for narrowboats.

 

So far as I'm aware the diesels used in the classic FX4 London cab were either the BMC 2.2, or the BMC 2.5.

 

Whilst these are occasionally seen in narrowboats, you could hardly say "often used", as really they are really quite rare, (and people with them seem not to know what they have, quite often )

 

I don't think I described a BMC diesel as a taxi engine - modern taxis are usually powered by a Japanese engine that is often marinised and (in my opinion) runs far too fast for narrowboat use. Choosing a sensible slow running engine for a narrowboat need not involve a huge investment. There are plenty of good reliable slow running engines around that will go on forever . . .

 

 

 

What I suspect you are referring to are the 1.5 and 1.8 BMCs - a different engine altogether, and as far as I know, not a taxi engine.

 

Before jumping to false conclusions, it might have helped if you had taken the time to understand that I was not referring to these early BMC engines. On the contrary to what you have assumed, I do know a little about the BMC engines - I have the petrol equivilent in my 1967 MGB!

 

When properly maintained, BMC diesels are excellent workhorses and have proved suitable for many marine applications although I do believe there are better and cheaper alternatives readily available for narrow boats.

[NB Alnwick]

Actually it may soon be time to consider the BMC 1.5 and 1.8 as a "vintage" engine given it's longevity and origins or indeed as a "traditional" narrowboat (pleasure) lump as so many have used them over a long period of time now.

 

 

Yes I think you are given your earlier rather sniffy post about buzzing modern engines and egg whisks!

 

Not sure why anyone should have connected my comment with a BMC engine - I had just spent several hours following a Canaltime hire boat that zig-zagged along the canal, making less than 3 mph with its engine buzzing away at what must have been near its maximum rpm. I am not sure of the make of engine but I think they use a marinised version of a Japanese taxi engine.

 

 

Other than making the canals a playground for the rich I see no practical way that all canal boats could use "proper" vintage marine engines. There aren't enough to go around for a start and cost is a factor for many people. Not everyone is going to afford £16K for a refurbished RN or indeed over £20K for a new one.

 

I am sure there are plenty of proper engines around for a fraction of the prices quoted. The Rigas two cylinder diesel that was fitted to the boat that we used to hire before we bought Alnwick is a good example - it recently sold (if it did sell) on eBay for less than £100. The Ruston-Hornsby designed two and three cylinder diesels now made in India are also very affordable.

[churchward]

Not sure why anyone should have connected my comment with a BMC engine - I had just spent several hours following a Canaltime hire boat that zig-zagged along the canal, making less than 3 mph with its engine buzzing away at what must have been near its maximum rpm. I am not sure of the make of engine but I think they use a marinised version of a Japanese taxi engine.

 

 

 

 

I am sure there are plenty of proper engines around for a fraction of the prices quoted. The Rigas two cylinder diesel that was fitted to the boat that we used to hire before we bought Alnwick is a good example - it recently sold (if it did sell) on eBay for less than £100. The Ruston-Hornsby designed two and three cylinder diesels now made in India are also very affordable.

We shouldn't turn the thread into an argument about the different uses of engine. However, the fact that two of us thought the same thing must show something abut your comments. Say taxi rather than car or truck engine then many will think of black cabs many ran with a form of BMC diesel. By the way the BMC 1.5 or 1.8 spins at similar RPM to Beta and other marinised Japanese engines.

 

Yes of course you can get cheaper older engines than the RN but we are back to the fact that there will be a limited supply as man of them are no longer made.

 

Many of the marinisation of the various Japanese makes are not vehicle engines either they are made for agricultural or industrial use such as the Kubota.

 

The point here is that to sneer and get snobbish about what kind of engine is in a narrowboat someone uses is rather futile and misses the point of boating which is to get out on the water and enjoy life and meet people not worry about where one comes in some self conceived hierarchy of boating.

 

You enjoy your older engine and why not but let's not put down others who don't use such an engine in their boat please.

[alan_fincher]

<SNIP>

 

I don't think I described a BMC diesel as a taxi engine - modern taxis are usually powered by a Japanese engine that is often marinised and (in my opinion) runs far too fast for narrowboat use.

 

<SNIP>

 

Before jumping to false conclusions, it might have helped if you had taken the time to understand that I was not referring to these early BMC engines. On the contrary to what you have assumed, I do know a little about the BMC engines - I have the petrol equivilent in my 1967 MGB!

Sorry for any confusion Graham - you are correct - jumping to conclusions. So many people seem to think the BMC 1.5 or 1.8s had a former life in taxis, that I fell into the trap of thinking that's what you were also saying.

 

I'm not confident enough of my facts to state anything in stone, but aren't just about all the modern Japanese narrow boat engines, (Kubota/Isuzu/Mitsibushi/etc) based on industrial rather than automotive units. I'd be somewhat surprised if many of the "narrow boat" sized ones were designed as car engines, as most are too powerful and sophisticated for such use, I would have thought.

 

I may be wrong, though, so I'd be interested if anyone can explain the parentage of these engines.

 

As an aside.....

 

If you found a CanalTime boat who's speed was as limited as you say, I can see advantages. The only boat I've witness pass us at ludicrous speed, (whilst we were moored), in the last 4 years was a CT one, and it was certainly at well, well in excess of the 4mph limit, as it sucked most of the water out from below us.

[churchward]

I'm not confident enough of my facts to state anything in stone, but aren't just about all the modern Japanese narrow boat engines, (Kubota/Isuzu/Mitsibushi/etc) based on industrial rather than automotive units. I'd be somewhat surprised if many of the "narrow boat" sized ones were designed as car engines, as most are too powerful and sophisticated for such use, I would have thought.

 

I may be wrong, though, so I'd be interested if anyone can explain the parentage of these engines.

You are correct.

[NB Alnwick]

You enjoy your older engine and why not but let's not put down others who don't use such an engine in their boat please.

 

I was not aware that I was trying to 'put down others' and if I ever gave such an impression then I am truly sorry because it was certainly not intended.

 

My comments about the engines fitted to many hire-boats are a personal opinion and from talking to the hirers who were struggling along in front of me yesterday, it seems that they were instructed that the engine had two speeds 'cruising speed' which was near maximum rpm (and much too fast for them to get through the mud and silt comfortably) and 'slow' which, commendably, they were told to use for passing moored boats. I am not familiar with Morse controls but if there are just two speed settings then the higher one must have been set far too high.

[alan_fincher]

You are correct.

So probably the only "taxi engines" in any significant number of canal boats then are BMC 2.2 or 2.5 units, (and I don't come across very many of them).

 

 

I am not familiar with Morse controls but if there are just two speed settings then the higher one must have been set far too high.

A Morse control, (like any other single lever control in this type of use), allows a complete selection of anything from idle, up to the maximum set on the engin. (Assuming it's correctly set up, of course).

 

CanalTime are not famous for their instruction of hirers - well actually I think they are infamous. One crew we had to help in one of the deepest double locks on the T&M said they had been sent to park their car whilst the instructional DVD was being shown.

 

I try never to blame the hirers, but rather to help them. I do get angry with the hire companies, though.