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Losing water


Peter Thornton

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It's a Pat Buckle boat. Ref the engine, I think it's about the 4th engine. The first lastedcsome time I believe then there were 3 quite quickly - from Calcutta I believe. The last engine was fitted whilst still under Ownerships and is about 7-9 years old I believe.

ref the raw water cooling, happy to be corrected and in fact there are no signs of it ever being fitted.

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Can't help you with further info, as the Buckle boat I had a share in still had it's (completely knackered) original Mitsubishi 1.4 engine in it when I sold my share.

My second shareboat was a Milburn fitted with a Calcut Boats BMC 1.8 which expired after 12 years and 13,000 hours and was being replaced with Beta 43 when I sold my share.

Hopefully someone will be able to describe the exact original cooling arrangement of an Ownerships Buckle boat fitted with a BMC 1.8 engine.

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2 hours ago, Peter Thornton said:

Thanks Tony.

this is an ex Ownerships boat of 1997 vintage. I think it started off with using raw canal water to cool and then was converted whilst part of Ownerships, along with all of the other boats. (I stand to be corrected!)

I don't know if the pictures help?

interestingly, today's cruise resulted in the header tank filling right up and then dripping out. The engine was working reasonably hard in a shallowish canal (Leeds Liverpool beyond Silsden) but no signs of overheating and the gauge on its normal 80. No signs of boiling or anything like that, the level just rose to the top of the tank and then dripped. So I'm wondering if the air pockets might have been filled and this is the result? The header is filled to the Min mark, about 1/4 full.

Tony, if it's cooled directly from the skin tank then is it all one system and is the header tank effectively connected directly to the skin tank?

i feel I'm learning a lot more than I expected this week! Thanks to all the tutors ......

 

Yes, the header tank should be connected directly to the rest of the system. My last post was to explain that you can not simply assume a manifold with Bowman on it is a heat exchanger. If you do so and call it an exchanger or heat exchanger you will confuse people and may not get good advice. For completeness I had to mentions how a heat exchanger manifolds can be used with a skin tank but it rare.

First I cant read the side of the manifold and it looks more likse a Polar or JGM one to me but its not important, only an idiot would fit so called Polar end caps nowadays because they fail easily. Those who know persuade a Bowman one to fit.

I am sure its a straight forward skin tank cooled boat and that brings up another point. Once you are sure any air in the system is out and the cooling has settled down over fill the header tank just once and then go for a good run. Coolant will overflow as it heats up but do not worry. When the whole system has cooled down and is nice and cold get a permanent marker and make a maximum mark on the expansion tank at the then water level. Ignore any moulded in markings.

The reason is that no one knows the volume of the skin tank and coolant pipes on a particular boat so any mark moulded into the tank are meaningless unless they just happen to suit your boat. They do not on most tank cooled boats, they tend to get the tank overfilled.

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Thanks Tony

That day may just have been today! I'll make a temporary mark with tape then monitor it over the next few days.

Hopefully we have just been getting all the air out of the system, otherwise it's back to looking for a leak!

Out of interest, what sort of oil consumption would you expect on one of these, also  mpg, or whatever the equivalent is? (On a 58ft boat)

we tend to put in about a pint of oil every 100 hours or so (not all at once) and we use about 1.1 to 1.3 litres of diesel per hour working out at about 1.75 litres per mile.

I know the mpl figures are a bit meaningless as locks make a big difference but do those figures sound about right?

Thanks very much for all your help, it's much appreciated.

 

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Both of those figures sound good for a BMC 1.8 that is getting on in hours.

With our BMC 1.8 engined shareboat, I  ran a spreadsheet for its last year before the engine change, recording fuel consumption in hours run and lock/miles for the various shareholders.

Fuel consumption varied between 1.1 and 2.2 litres per hours, depending upon "driving style" and how heavily locked the route was.

Higher cruising revs and relatively lock free routes used the most fuel.

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  • 2 weeks later...
8 minutes ago, Peter Thornton said:

Not sure whether it’s a Polar unit, but I think you’ve found the problem. It’s damp around there in the morning. 

If it is a Polar unit replacing the seal/neck is not easy. Based on  my experience the neck is secured by a large nut that  will both be corroded and impossible to grip through the end cap hole. I had to remove the manifold, cut the neck off flush with the surface of the manifold, coĺlapse the remaining part, have the hole reduced in size with weld then drill, tap and fit a flush fitting neck. ( if you consider fitting a Bowman neck you will find the existing hole too large ) . Somewhere I've got a note of where igot the replacement neck from but it would be a few days before i could dig the info out.

 

Frank

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On 9/25/2017 at 17:28, cuthound said:

I've had shares in Ownerships boats built in 1992 and 2002. Neither of these used raw water cooling.

As virtually all Ownerships boats were "of a type", those of that type were similar.

In 1997 the boats were either the last of the Pat Buckle type or the first of the Graham Reeves (fitted out by John Milburn) type. To the best of my knowledge no Ownerships boat ever used raw water cooling.

However it is unlikely that the engine in Sunseeker is the original, most  BMC 1.8's lasted 8-12 years in shared ownership usage. That header tank is not typical of a BMC 1.8 installation if it is in a Graham Reeves shell fitted out by John Milburn. On the semi-trads they had a long pipe rising from the skin tank which the water expanded up, with a vented screw on BSP type cap. It emerged through a hole in the hexagrip cover ofthe gas locker on the port side of the boat (behind the morse control).

Regarding raw water cooling, many of the earlier Pat Buckle/BMC 1.8 boats had wet exhaust systems complete with mud box, strainer/filter separate pump and drive belt. However, engine cooling was always via skin tank.

Although very quiet, these wet systems proved unreliable in operation with most being replaced with 'hospital' silencers. I guess retention of redundant mud boxes in some cases has led to the myth these boats were originally raw water cooled.

Early boats tended not to have header tanks and were prone to overheating due to airlocks.  Many had them retrofitted.  Later ones had the long pipe header tank arrangement you describe.

 

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