Calorifiers - Connection To Engine

[floydraser]

I was on the verge of ordering the calorifier and expansion tank but got the jitters at the last minute. There’s no rush but I want to be sure I can make satisfactory connections to the engine before jumping in with both feet.

The engine is a Thornycroft OE160 which is a British Leyland – Triumph 2.6lt 4 cyl derivative. I have experience of rebuilding engines but not diesels, and not marine versions.

I have worked out that I need to connect to the bypass next to the thermostat housing but is it just a matter of diverting the bypass via the calorifier, or should I be teeing into the bypass hose with the return somewhere else? I've just spotted a blanking plug - could that be part of the answer?

Thanks again, the video may help.

 

[Vaughan]

I am probably putting my head "on the block" by answering this and please excuse the pun -

Cylinder block?  

I don't know this engine, but there are some basic principles :

The calorifier tank must be connected to the internal or "fresh" water side of the cooling system. So forget about the "raw" or river water side, including the raw water pump and the heat exchanger.

Hot water will rise in the system and cold water will drop. In other words, convection. So the top part of the engine cooling circuit is connected to the lower part of the spiral tubing in the calorifier. 

The cooling circuit is pumped by the "circulating" water pump - not the "raw" water pump - on the front of the engine. So the top pipe to your calorifier must be somewhere after the pump and the return must be somewhere between where the cooling water comes out of the bottom of the block and goes back to the pump. The top feed should also not be between the pump and the thermostat, or the cooling effect of the calorifier might cause the thermostat to open late and run the engine too hot.

There are threaded drillings in all cylinder heads, which are there for temperature gauge senders and one of these ( usually the front one if the engine is at an angle) can be used for the top pipe to the bottom of the calorifier. The return pipe to the engine will probably be in the form of a braised connection, fitted as a T piece into the cooling hose.

Don't forget that the "drinking" water system in the hot tank must be fitted with a pressure relief valve. Otherwise if you overheat the engine, you might also boil the drinking water and explode your nice new tank.

Do you get the impression that it might be a great deal easier to have this job done by a boatyard?

[floydraser]

Thanks for the reply. I think you've confirmed what I was beginning to think: The blanking plug visible on the side of the header tank I'm pretty sure is part of the fresh water cooling system and therefore a good place for the return from the top of the calorifier loop?

The raw water pump is on this side of the engine (video still) driven by the same shaft as the injection pump. The fresh water pump is in the "traditional" place behind the front pulley, on the front of the block. I still think I'll have to tee into the bypass hose though, but on the next visit I'll have another good look around to see if there are any other plugs on the block.

I've done a bit of comparison and the calorifier I'm going for comes with everything needed including a pressure relief valve. Ditto the matching expansion tank.

Boatyard? Not until I've been forced to admit the challenge has beaten me! They can however, gladly have the forthcoming antifouling job!

 

[Vaughan]

20 minutes ago, floydraser said:

The blanking plug visible on the side of the header tank I'm pretty sure is part of the fresh water cooling system and therefore a good place for the return from the top of the calorifier loop?

You need to take the top feed from the head, as that is where the hot water will come from.

If you then return to the heat exchanger you will be on the "wrong side" of the circ. pump and will not get a flow of water. You will also get trouble with air locks.

Anyway, at least I offered a reply.

 

[Smoggy]

The standard take offs on my volvo's are only a couple of inches apart and effectively bypass the thermostats and it warms the water quickly enough, it means the engine with the calofier connected warms slower but not much slower.

On my old boat I took one feed from a drilling in the head and one from the bottom of the block and worked just as well, probably slightly better but that had both engines feeding the calorifier (twin coil calorifier not linked engines), this setup also effectively bypassed the thermostat.

If any hoses dip down then up you will need a way to get the air out unless you are very lucky, once bled it should work fine.

Remember convection can also take heat from the calorifier back to the engine block when on an immersion heater.

[floydraser]

35 minutes ago, Vaughan said:

Anyway, at least I offered a reply.

 

And very welcome too; you started the ball rolling.

[floydraser]

Ok the penny has started to drop, a little; I got my flows and returns back to front. I'm a bit slow but I normally get there in the end.

I've just found a very good diagram via Google which makes it a bit clearer. 

[Vaughan]

I have just had a brainstorm!

I got a bit thrown by the "bypass hose" you mentioned, as I hadn't heard of that, but it is possible that this is a piece of hose which has been fitted simply to blank off the connections which would have been used for the cab heater, if the engine was fitted in a vehicle.

In which case, all you need is to use those two ends, as a cab heater is exactly the same principle as a calorifier in a boat.

A photo would help if possible.

[floydraser]

3 hours ago, Vaughan said:

I have just had a brainstorm!

Steady on, someone may get hurt!

My original thought/hope was the same, but then I thought it can't be that simple; nothing ever is... 

I will have a good look around for more tappings in the block and head, and get down there and see exactly where the "bypass hose" goes to/from. It should go from the thermostat housing into the block, the water pump being a separate item just below. It's a bit hard to see with that Bowman heat exchanger stuck on top. The video is the best I've got up till now but I'll record everything as ever when I do the job.

The engine was fitted in the old Scammel Mechanical Horse 3 wheeler and the Karrier, which were always dustbin lorries around here. And I think if you could find a very old lorry driver he may say they didn't have heaters!

Thanks again.

[annv]

NO!! the bypass is to allow circulation within the block when thermostat is closed, as i said be for, the flow of coolant from the engine comes USUALLY from the top of the cylinder head usually at the rear this is the hottest part of the engine, this is piped to the TOP califorafia heating coil the bottom heating coil ie return goes back to the engine usually at or near the ENGINE circulating pump the circulation of engine coolant through the coils  is pumped by the engine pump. DO NOT attach any pipes to the heat exchanger from the caloriafia. There are blanking plugs in the engine that need removing and hose tails connecting in place off, usually 1/2" dia, you use the connections that if the engine was in a car are where the heater would be connected to, when marinized these are blanked off. John 

[floydraser]

Thanks John.

Here's the calorifier I'm looking at: http://www.surejust.co.uk/15-litre-horizontal-single-coil-surecal-calorifier

Fitting instructions: http://www.surejust.co.uk/surecal-horizontal-calorifier-connection-instructions

You'll see the top and bottom connections are for the "drinking" water and the engine water pipes side to side, but I get the idea regarding flow and return. 

So I could do with finding a ready tapped connection to the rear of the head for the flow, and the return goes to the car equivalent of the bottom hose, or thereabouts?

I was hoping to find blanked off connections as there must have a calorifier fitted before. Where they around in 1970?

[annv]

Hi Yes calorifora's have been around for longer than 1970 they where originally just a cylinder with a coil inserted inside exactly the same as a house one but smaller, not sure why you need to pay extra for a thermostatically controlled valve in outlet pipe, i use the cheaper plain coil in and out ones with double coils when separate engine and boiler/heaters are fitted this often can have a thermo syfan action and pre heat the engine in cold weather. I prefer the upright type as they are cheaper and take up less room than horizontal ones, but!! your decision why not get a haynes manual for a car this will show you where the hater pipes are connected to the engine, alternatively are there  two blanking plugs that have no or different paint colour at the right places, your picture doesn't show anything get a close up of the top of rear head and the back of water pump to show up these area's. John

[MauriceMynah]

10 minutes ago, annv said:

 why not get a haynes manual for a car this will show you where the hater pipes are connected to the engine, 

Isn't there enough ill will out there without Haynes adding to it?

[Regulo]

The thermostatically controlled valve on the outlet ensures that the water at the hot taps isn't at the same temperature as that in the calorifier, which will be approaching the running temperature of the engine. 85 degrees C plus - enough to badly burn you.

[Smoggy]

The thermo valve are very useful if you are likely to have youngsters on board and even with knowledgable adults they tend to make your hot water go further as it's easy to use way too hot then add lots of cold till it's useable.

I recon you'd be hard pushed to find a haynes manual for that engine, even then haynes are known for a good few cockups.

How about asking these people? https://www.thornycroftengines.com/contact

They must have all sorts of old info lurking somewhere or the old guy in the workshop that will tell you straight from the top of his head.

[floydraser]

I won't be paying extra for the thormo valve; it comes with the calorifier from the manufacturer. I think it's recommended modern practice to fit them and I want to end up with a proper job and honour the T&Cs of the warranty. 

I've just bought a Haynes manual for a Tornado jet fighter and another for the Moon (stocking fillers for Grandchildren) but they haven't got round to the Scammel Mechanical Horse yet. Pitty. No matter though; I do have an owner's manual for the engine and gearbox, and a workshop manual for the engine but no tappings shown, and no mention of calorifiers. Looking at some of my "older" videos I can see something bolted to the back end of the head but I can't make out what it is until a I get over there again. I could call Thornycroft engines after Christmas but hopefully I'll be sorted by then. They don't list much if any info about these engines (the OE.138 & OE.160) on their website so hopefully the old guy in the workshop will still be around!

In the meantime, here's one I prepared earlier:

 

A bit of engine porn for you...

 

[D46]

2 hours ago, floydraser said:

I won't be paying extra for the thormo valve; it comes with the calorifier from the manufacturer. I think it's recommended modern practice to fit them and I want to end up with a proper job and honour the T&Cs of the warranty. 

I've just bought a Haynes manual for a Tornado jet fighter and another for the Moon (stocking fillers for Grandchildren) but they haven't got round to the Scammel Mechanical Horse yet. Pitty. No matter though; I do have an owner's manual for the engine and gearbox, and a workshop manual for the engine but no tappings shown, and no mention of calorifiers. Looking at some of my "older" videos I can see something bolted to the back end of the head but I can't make out what it is until a I get over there again. I could call Thornycroft engines after Christmas but hopefully I'll be sorted by then. They don't list much if any info about these engines (the OE.138 & OE.160) on their website so hopefully the old guy in the workshop will still be around!

In the meantime, here's one I prepared earlier:

 

A bit of engine porn for you...

 

Nice rover ( ex Buick) V8 , well designed headers too ( all the same length)  😀.

Calorifier wise a mixer on the tank will give you more hot water and is useful as far as not delivering red hot water to hot outlets , me I removed mine as it supply's hot to taps that are mixer taps anyway so I can reduce it there but that's personal choice .

As for horizontal or vertical colorifiers it depends on the installation really but it's worth bearing in mind vertical ones from ASAP the fittings ie hose connections and PRV Valve + mixer valve are all extra , hot pot or sure just are exactly the same item really .

Connection wise it's normally from a tapped connection from the back of the cylinder head ( I'll be amazed if there isn't one ) return is to immediately before the engine's water pump inlet as John discribed , that bit might need a suitable tee joint making up .

[annv]

Hi I prefer to have the thermostatic control on the shower valves where it can be adjusted easily, this then gives hotter water at the kitchen sink where you need hot water to clean pots pans hygienically and as most marine engines have a 74 degree thermostat i find this best, can you not fit a bigger cylinder then a 15lt not much capacity there only 3 gallons in english,   as i said upright ones are cheaper and tend to hold larger amounts for the room they take up. John

[StillCruising]

Hi.

I may be wrong (I often am according to my wife).  I thought that the Scammell Scarab diesel  version was a Perkin’s lump but the later Scammell Townsman (GRP cab) had the Layland OM160 borrowed from the Layland 20 & 90 Commercials and had  heaters / demisters as standard.  If this is the case your engine will have the heater pipe points for sure. There a number of both types restored at various heritage railways etc so it could be worth your while looking in that direction or maybe trying the ‘Scammell Register ‘ (www.Scammell Register.co.uk) .

Regards

Bob

[Smoggy]

Fit your calorifier and get hoses 1.5 metres longer than you expect to need and just try any high & low tapping on the block/head and see how it runs watching the temp gauge and checking the domestic water temp as you go, if it seems ok and doesn't take an age for the engine to warm up leave it else change it and try something different, bsp hosetails are not expensive as long as you are not chopping into hoses each time.

There's probably no two plumbed the same out there anyway, at least your domestic plumbing will be done and you will have hot water when plugged in via immersion even if it takes a while to get engine connected spot on.

The yellow circle shows how close mine are apart (that's the thermostat housing, one each side of stats), the hose is to stop the coolant peeing out while they were out.

This setup gives me hotish water within 20 mins of a cold start at river speeds (1000-1200rpm) and both engines warm up fairly close together.

 

This is when I had to take them out to replace the fuel tanks, never again I hope.

I now have the same take offs on the other engine plumbed to a heater matrix blowing under the cabin steps via a bilge blower fan, makes life a bit more comfortable for the slightly chill days that are not quite worth firing up the eberspacher for, this works ok too.

[floydraser]

Thanks again guys.

Smoggy, The photo is a great help; I wouldn't have thought the connections so close together would have worked but if that's what I find, I won't be worried.

Bob, I think (contrary to you wife) that you're right. The engine was also used in tractors but is generally an industrial engine.

Choice of calorifier comes down to price, availability and practicality: Surejust do an upright but only 10 litres, around the same price as the equivalent horizontal. Their calorifiers come with matching/recommended fittings and mountings. With others they are extra unless I shop around, then they've got to match and fit properly, and if anything wasn't quite right I would be kicking myself and end up with a poor job.

15 litres is just a tad bigger than the heater in our touring caravan, which has a shower. I don't see us spending more than a couple of days at a time on the boat just yet and if we do, it'll be in the summer. So heating more water for such a short time would be wasteful. Any future owner will have to replace just the calorifier for a larger one if needed; no plumbing to do, and the cost would have to seen in relation to overall purchase price. No plans to sell at all, hence the 15 litre calorifier! 

Yes D46, that's the one. Not quite "prepared" though; removed from an old SD1 and cleaned up to be measured for a fitting. The exhaust is a BL Motorsport Rally spec replica and the blue subframe was for fitting to this:

 

[stumpy]

Floydraser - it might be worth getting in touch with Ipswich Transport Museum, they have a Scammel Scarab which I think is up and running. The museum is run by volunteers who are very knowledgeable (I used to work with one who is a total bus-geek). They're closed until after new year but an E mail to the office on 'enquiries @ipswichtransportmuseum.co.UK' can't hurt.

[Smoggy]

A tr with the proper engine then, wouldn't fancy working on it in situ though.

the thing with the connections close together is that if the engine temp drops the stats shut and the calorifier get the heat, theres no point paying out diesel to heat a river, stats don't close the circuit they just open an easier circuit, some will still go the other way.

[MauriceMynah]

13 hours ago, Smoggy said:

stats don't close the circuit they just open an easier circuit, some will still go the other way.

Well we have to get our jollies where we can.

[floydraser]

Well I nipped over on Monday/Tuesday and near the top of the agenda but below exchanging fridges and lifting the diesel tank was looking for possible hose connections on the engine. I'm stumped. My information was that the original engine would have been the 2.3lt version but this is a 2.6lt and doesn't look 50 years old. So it's quite possible that my engine came from a source that didn't require any further connections. 

I'm putting this part of the project on hold while I do more investigation and in the meantime I'll look at other means. 

Here's the vid:

https://youtu.be/1X8G8dbot1k