Secondary waterpump

[p6rob]

Hi again,

 

I'm still trying to get the boat to run nicely, apart from the plumes of smoke, which I publicly apologis for, (I'm hoping it's to do with the prolonged bedding in period and that it will settle down to an acceptable level once the boat has a few more miles under it's belt) it still overheats. I think an airlock got purged during this afternoons trip as, initially, the first skin tank was warm, whereas the second tank was stone cold. After this airlock was belched out, the second tank started to warm up, but by then, I'd discovered the Cambrian Wharf visitor moorings were full, so headed back to Sherborne Wharf.

 

Basically, I think the coolant is struggling to travel around the circuit because the engine pump can't push the huge volume of water around the numerous 90 deg bends in the circuit between engine and skin tanks.

Does it sound sensible to add another pump between the starboard and port skin tank? I'm thinking of fitting a thermostatically controlled electric one as I think it would be easier to plumb in, but, if a mechanical pulley driven one is more suitable, I'd go with expert opinion.

 

If this is a sensible mod, what pump make/type would get your vote? The external hoses are all 32mm id except for restrictions into and out of the engine and gearbox oil cooler heat exchangers.

At the moment, and it was only a very short trip, it seems that running at anything over tickover causes overheating but it was stable cruising at tickover.

 

Failing that, is it possible to convert to raw water cooling or is that just changing one set of problems for another?

 

Thanks in advance

 

Robert

 

[bizzard]

Hi again,

 

I'm still trying to get the boat to run nicely, apart from the plumes of smoke, which I publicly apologis for, (I'm hoping it's to do with the prolonged bedding in period and that it will settle down to an acceptable level once the boat has a few more miles under it's belt) it still overheats. I think an airlock got purged during this afternoons trip as, initially, the first skin tank was warm, whereas the second tank was stone cold. After this airlock was belched out, the second tank started to warm up, but by then, I'd discovered the Cambrian Wharf visitor moorings were full, so headed back to Sherborne Wharf.

 

Basically, I think the coolant is struggling to travel around the circuit because the engine pump can't push the huge volume of water around the numerous 90 deg bends in the circuit between engine and skin tanks.

Does it sound sensible to add another pump between the starboard and port skin tank? I'm thinking of fitting a thermostatically controlled electric one as I think it would be easier to plumb in, but, if a mechanical pulley driven one is more suitable, I'd go with expert opinion.

 

If this is a sensible mod, what pump make/type would get your vote? The external hoses are all 32mm id except for restrictions into and out of the engine and gearbox oil cooler heat exchangers.

At the moment, and it was only a very short trip, it seems that running at anything over tickover causes overheating but it was stable cruising at tickover.

 

Failing that, is it possible to convert to raw water cooling or is that just changing one set of problems for another?

 

Thanks in advance

 

Robert

 

It might be worth trying streamlining the circuit by doing away with the elbows, they act as brakes to the flow, and work out nice gentle bends instead.

[p6rob]

That's a good idea Bizzard. So far, I managed to take one elbow out of the circuit. I think, with a bit of re-engineering another 2 or 3 could be removed but parts will need to be obtained first.

[Charlotte Burnett]

Don't convert to raw water....I dream of skin tanks!

[p6rob]

I dream of a smoke free, cool running narrowboat. I'm pretty sure the canalfolk around me share the same ambition. It'll happen, one day, soon.

Is your raw water system a chore, Charlotte?

[Charlotte Burnett]

It's a bit of a pain but tbh it's more as a result of being poorly installed and I've not got around to sorting it out yet. I have no strainer on the hull fitting so sometimes, a bag plugs it and I have to go fishing for it. The inboard strainer is badly mounted and difficult to access and far too close to the inverter for comfort when I have to clean it. As a result, I don't do it as often as I should. I then get mud in my vasaline when I reseal it and swear a lot when this one ends up in my handbag by accident. Clearing the bowden tubes is a slow, joyless process and more importantly, suggests that mud has at points entered beyond there and into my water jacket.

 

Will I trash the back cabin to fit skin tanks? No. What I would like to do though is fit twin inlets running to twin mud boxes prior to a double valved T. This would enable switching from a dirty line to a clean one without having to race through Camden locks single handed managing an overheating Gardner. I will also fit a header tank and run an indirect system where the raw water cools a closed system via a heat exchanger.

[p6rob]

Hmm, that does sound 'challenging'

Is indirect the ideal solution?

 

TIA

 

Rob

[RLWP]

Skin tank is the ideal solution

 

There is something wrong here beyond 'the water can't get around the corners'

 

Richard

[casper ghost]

My coolant water is pumped by a bosch 12 volt car auxillary water pump, bought for £1 from a wrecked car. saved me having to fit a water pump to my engine which would have only been gravity fed.

Casp'

[p6rob]

Indeed. The boat is 30 years old so this system must have worked reasonably well until fairly recently.

 

There was still some trapped air on the last trip which, once shifted did see the second skin tank warming up. By then I'd found there wasn't enough space on the VMs at Cambrian Wharf, so headed back to Sherborne.

 

It's been overplated in the past, and it's probably quite fouled, so presumably thermal transfer won't be what it once was.

Skin tank is the ideal solution

 

There is something wrong here beyond 'the water can't get around the corners'

 

Richard

My coolant water is pumped by a bosch 12 volt car auxillary water pump, bought for £1 from a wrecked car. saved me having to fit a water pump to my engine which would have only been gravity fed.

Casp'

Hi Casp, Do you know what vehicle it was off so I can start looking around? I've been eyeing up a Davies Craig pump and controller but it's rather more than a quid.

[smileypete]

Skin tanks can trap air at the top, which may then escape elsewhere and cause problems, especially if the hose layout is poor.

 

If it's a common engine might be good to find out what the marinisers say in their manual about installing and bleeding, I reckon much problems occur 'coz people don't 'read the fine manual'!

 

Also trawl the forum search facility for past discussions, plus a look at the install instructions for similar engines might be helpful.

 

cheers, Pete.

~smpt~