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Sabb 2J - calorifier connection


PaulJ

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None of the Sabb owners I have encountered over the years have mentioned the cooling as an issue worth modifying. I wonder what Johno at UCC in Braunston would advise.He is an expert on using these engines both in his own fleet and servicing and repairing customers engines.

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I don't like the idea of prolonging the warm up time of any engine, the faster it's at operating temperature the better.

 

Therefore the idea of passing hot water to a calorifier and returning cold is less than ideal. A bypass is there for good reason.

 

One idea I have considered is using a thermostatic mixing or blending valve on the return from the calorifier and keel, such that when the return temperature of the calorifier is above a threshold the return feed would switch to the keel cold return.

 

Most radiators/engines work on a 20degsC temperature between input and output so if the engine is working at 70degsC the maximum return temperature is 50, so I'm make it initially 40. To be honest 70degsC sounds low and might be in part because of the very low temperature of the efficient keel cooling.

 

This is the sort of blender I would consider:

http://www.ebay.co.uk/itm/Reliance-Underfloor-Heating-Blending-Mixing-Valve-28mm-Heatguard-/261406633824

 

Not cheap I have to admit, but there might be others and may solve all your problems. I would think 28mm would be sufficient, anything larger becomes prohibitively expensive. 2 x 22mm would give almost the same impedance/flow rate.

 

Just an idea.

 

 

I agree that delaying engine warm up is far from ideal. It must be considered though that wherever you plumb a calorifier, it will add to the heat soak.

 

By far the best automated method is to employ a twin thermostat system as mentioned at the end of this post, and as shown/described below. Many larger marine engines employ such including the whole Barrus Shire range now.

 

RDG60310228-Issue2-Shire12CompleteManual

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  • 2 weeks later...

There does seem to be a sudden rash of people who are all wrestling with newly fitted Sabb and water flows!

Peter Bullfinch is proposing that we all meet up next year.

We could call ourselves the Sabb Owners Calorifier Knowledge Society (SOCKS) ?????

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That's a lovely looking installation Chop. Well done. I believe that the Sabb engine thermostat can be housed at either end of the heat exchanger box to make it more convenient for your plumbing layout.

It would be interesting to know if any other Sabb owners would be up for a get together. I suppose even a nucleus of two would be a start!

Edited by Peter-Bullfinch
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Looking good on your blog Chop- looked out for you last Saturday (I was moving that new widebeam ) but you was already in the water by then.

Im up for a meet up Peter. Hopefully Sabb should be running and boat finished enough to get it moving!

Engine just in today in its new colour- just got to line it all up now and plumb it in...

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Hi Paul and Chop glad your installs are going ok and thanks to Peter for all the pictures and info

which I have found helpful,post-25801-0-03814100-1481411879_thumb.jpg would love to meet up with other Sabb owners but it will be a while before the boats finished

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That's a lovely looking installation Chop. Well done. I believe that the Sabb engine thermostat can be housed at either end of the heat exchanger box to make it more convenient for your plumbing layout.

It would be interesting to know if any other Sabb owners would be up for a get together. I suppose even a nucleus of two would be a start!

Yes Peter, I think that's right, the same goes for the exhaust outlet.

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So, I've checked my thermostat and it's a 75 degree one (Quite mucky too, looks like the engine needs a damn good flushing.

I checked my skin tanks and they seem to be free from blockages, so I decided to try a change from raw water to skin tank cooling making a closed circuit with the calorifier.

JohnO seems to think that, as I've overplated the skin tanks, I'll get overheating problems. :0(

If it looks like it's going to overheat, I'll add some kind of heat exchanger up higher than the engine, cooled by raw water. It will then, hopefully self drain, while the closed circuit can be filled with antifreeze.

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The first time we went over the Ribble crossing years ago we were advised (wrongly) to go with plenty of speed on the length all along the River Douglas. I was concerned about overheating so I asked my non boating passenger please would she run the bath. She looked quizzically at me but happily complied. I watched the temperature guage and the whole performance made virtually no difference. The engine didn't overheat. I was concerned about stressing a relatively elderly engine so I slowed back to our usual gentle river speed. Much pleasanter. I relate this only to say that sometimes trusting your own instincts and being thoughtful is sometimes a worthwhile path to take.

I think you are right about your keel tank project. Try it and if it is OK, then that's a good result. On the other hand Johno is always worth listening to!

I think we used the bath full for some laundry....

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Youtube videos of me boat running - albiet with temporary exhaust, fuel and controls!

Sorry Chop- couldnt resist

If I said I was chuffed that would be an understatement. Engine and prop push the boat along effortlessly on tickover against the flow ☺

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Cheers chop. Reckon you are going to love the gruntiness.Fingers crossed on the skin tank being up to it. Reckon that heat exchanger will sort it if not.Even after running several hours none of my pipes have got much above blood temperature. Will check my stat etc when I get courage to swap the exhaust and thermostat round.

Might sound and go nice but I still got the engine room,bathroom and bedroom to refit yet

Edited by PaulJ
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Well done Paul. The engine sounds really good. I was told some years ago by another Sabb owner that these engines were commonly fitted into ships lifeboats and as such were tested with the engines running for quite a few minutes out of the water without overheating. Another test was the engine needing to run leaning over at quite an angle. I have no idea if these were official test requirements or not. Abandoning ship, I would imagine, with a lifeboat it would be best to start the engine once in the water and not dangling about in mid air with the risk of a moving prop near anyone floating around underneath. I'm sure someone here knows what should happen in these circumstances.

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Thanks Peter- way to go yet but Im still grinning ear to ear :-)

Im pretty sure mine did indeed come out of a lifeboat and is low hours. Certainly when I took the gearbox off the splines, drive plate and internal bellhousing were immaculate with no wear visible (relief) Similary the flywheel ring gear has little wear.

The diesel filter has a really tall collection of fittings for the return pipe.I thought it had been bodged. Turns out the reason for this is that the lifeboat engines were actually fitted with it and is a one way valve so the lifeboat could be turned over 360 degrees with no fuel running back into the engine! Amazing stuff but I dont intend to try this theory out :-D

I will put up a video / pics of engine sometime soon - if you see the chaos the engine is sitting in at the moment you would realise why I havent yet..:-D

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In post #36 Chop refers to JohnO just to be clear, that be me.
U.C.C. Jono prefers to be known as Jonathan Hewitt nowadays.
Jonathan knows more about The Sabb than I will ever know.
Concerning life boat use, this document
http://www.sleeman-hawken.co.uk/files/identify-your-engine-gearbox.pdf
basically,
H/G - single cylinder
GA - life boats, air cooled
2H - yachts, lightweight alloy block, shorter stroke, lower engine height.
2G/2J - fishing vessels, Tough, Robust, Sturdy!
by’eck is totally on the money with the twin thermostat system.
I have recently installed two Shire engines, really impressed, like their use of exhaust manifold.
wonder if this unit is available or what would be an alternative.
A get together sounds good.

I will just leave these here!

SABB semi-diesel A,B,C,D,

SABB type D 6-12 HK semi-diesel

Edited by JohnO
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O.K. theory time, if, with my overplated skin tanks, she runs a tad hot, would using Evan's waterless coolant help? Anyone used it?

Also, Marine Enterprises state that they have raw water or skin cooled versions, do they need a different pump? i.e. will my pump, which is allegedly set up for raw water, work OK through my skin tanks?

Edited by Chop!
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