Coolant Flow LW's

[mark99]

Does anyone know the exact flow route the engine coolant takes when pumped into the cylinder block/head? (not concerned re other circuits like calorifier or skin tank at the mo).

 

The link below from Marine Power Services shows a picture of 2LW restoration. Look at picture 4, you can see the entry point at bottom of cylinder block (pump entry) and 4 ports on opposite sides. Then it must flow round cylinder head (not shown in picture) to arrive at other side and enter into the commonly used coolant header pipe.

 

http://www.marinepowerservices.co.uk/engines/past-engines/20-1953-gardner-2lw

 

I can't find a sectional drawing of a cylinder block/head anywhere.

 

Below is 2 LW showing the coolant header pipe (marked "engine top header"). And inlet to cylinder block (red elbow marked "engine inlet").

 

Edited October 26, 2015 by mark99

[LEO]

Hi M,

 

I will get some pics of my installation to-day, perhaps Steamraiser will be along with the answer.

 

M.

[mark99]

Cheers Mike.

 

What I'm trying to fully understand is that on the coolant header there are two ends, and if the water pump by means of the cylinder coolant galleyways, exerts a similar pressure at both ends of the header.

 

If it does then it would make more sense NOT to connect a cooling circuit at both ends of the header (inlet one end and outlet the other) as the pressure difference required to shift coolant round circuit could be largely nullified.

Edited October 27, 2015 by mark99

[martyn 1]

Essentially the block is hollow. the water enters via the port at the bottom of the block which you pointed out in photo 4 of your link, the water then passes from the block into the head via 9 x 5/16" ish dia holes in the top of the block, the water joints between the block and head being sealed via o rings (You can see these in photo 3 on the same link). once in the head again the water jacket is common to both cylinders and the water flows around inside and out of both the ports into the top rail.

 

Your new note appeared as I was writing this, the reason your header has two ends is because it is a rail meant for a 4LW with another cylinder head. a proper 2LW one only has a flange at one end to take in your case the thermostat assembly. which way round you bolt the header on doesn't matter but if you were to only use one of the ports the cylinder at the other end would suffer from poor coolant flow as all the water will be flowing to the open port. As for similar pressures on these port it will depend how scaled up the jacket in the head is as some of the small passages are prone to blocking up which would alter the flow.

Edited October 27, 2015 by martyn 1

[LEO]

Essentially the block is hollow. the water enters via the port at the bottom of the block which you pointed out in photo 4 of your link, the water then passes from the block into the head via 9 x 5/16" ish dia holes in the top of the block, the water joints between the block and head being sealed via o rings (You can see these in photo 3 on the same link). once in the head again the water jacket is common to both cylinders and the water flows around inside and out of both the ports into the top rail.

 

Your new note appeared as I was writing this, the reason your header has two ends is because it is a rail meant for a 4LW with another cylinder head. a proper 2LW one only has a flange at one end to take in your case the thermostat assembly. which way round you bolt the header on doesn't matter but if you were to only use one of the ports the cylinder at the other end would suffer from poor coolant flow as all the water will be flowing to the open port. As for similar pressures on these port it will depend how scaled up the jacket in the head is as some of the small passages are prone to blocking up which would alter the flow.

 

Hi Martyn

 

The definitive answer as ever...........

 

Mike.

[mark99]

 

Hi Martyn

 

The definitive answer as ever...........

 

Mike.

 

Excellent reply.

 

Just to be clear Martyn, on the photo above would you suggest this is not the best way to cool the engine? would you prefer to see the flow entering/leaving where the plug is on the nearside of header travelling along the header and leaving via the far (thermostat) end?

 

Out of curiosity, I'll field test with my electronic temp gauge to check temp along the header - esp the "dead" end with the plug in.

 

NB there is a bypass circuit you can't see on photo above.

Edited October 27, 2015 by mark99

[Cloudinspector]

Excellent reply.

 

Just to be clear Martyn, on the photo above would you suggest this is not the best way to cool the engine? would you prefer to see the flow entering/leaving where the plug is on the nearside of header travelling along the header and leaving via the far (thermostat) end?

 

Out of curiosity, I'll field test with my electronic temp gauge to check temp along the header - esp the "dead" end with the plug in.

 

NB there is a bypass circuit you can't see on photo above.

I'm guessing that if both ends are utilised the coolant would flow from both ends? On mine the calorifier circuit is connected to the end with the plug in on your photo. Initially I thought the coolant from the calorifier came back in that way but now I think the opposite is the case.

[martyn 1]

 

Excellent reply.

 

Just to be clear Martyn, on the photo above would you suggest this is not the best way to cool the engine? would you prefer to see the flow entering/leaving where the plug is on the nearside of header travelling along the header and leaving via the far (thermostat) end?

 

Out of curiosity, I'll field test with my electronic temp gauge to check temp along the header - esp the "dead" end with the plug in.

 

NB there is a bypass circuit you can't see on photo above.

I don't quite follow what you mean, from what I can see in the picture the setup you have is pretty typical. water comes from the keel tank into the large port on the water pump, it then leaves the pump and enter the block/head. it exits the head at the rail on the top of the engine where it meets the thermostat. when the themostat is open the water flows out of the fitting in the end back to the keel tank. when the stat is closed it passes down a pipe from the side of the thermostat back to the pump (this is the line that normally has the calorifier in it). now if your thermostat is a fully closing type (e,g, when it is open back to the keel tank it fully blocks the pipe back to the pump then you would need to take your calorifier water from one of the ports on the water rail.

I'm guessing that if both ends are utilised the coolant would flow from both ends? On mine the calorifier circuit is connected to the end with the plug in on your photo. Initially I thought the coolant from the calorifier came back in that way but now I think the opposite is the case.

The opposite is the case as you say , hot water rises so the rail on the top is the hottest point so this is the out to tank, radiator, calorifier and the bottom (water pump end) is the cold in.

[mark99]

Martyn, Thanks.

 

What I'm trying to understand is that if the coolant circuit is connected to BOTH ends of the coolant header, is there a risk the pump would not circulate coolant properly? as both ends of the header will be pushing water out and these left and right flows will meet somewhere in the middle of coolant ring?.

 

You can see my connection in my photo above. Coolant exits one end of header. (I know it gets back via bypass circuit or the main skin tank circuit).

 

Cloud Inspectors circuit is different - his coolant is moved out of one end of header and returns the other end of header.

 

You can see Cloud Inspectors circuit here (2nd page shows the return to opposite end of header).

 

http://www.canalworld.net/forums/index.php?showtopic=80157

Edited October 27, 2015 by mark99

[martyn 1]

Looking at the other thread I would have said yours looks correct and Cloud Inspectors is a little odd on setup. In most installations the bypass line back to the water pump is either removed or modified so the water comes out of the thermostat which is on one side of the water pump and is returned into the pump where the bypass pipe once was fitted, which is on the other side of the pump and therefore ensures flow. now without complicating things some still have the bypass pipe but modified with valves to allow fine adjustment of how much water goes around the calorifier or misses it and goes straight to the pump.

 

If Cloud Inspectors calorifier circuit goes to the calorifier via the tee in his picture on the bypass line and returns to the top water rail then it is essentially a deed head circuit and will never really make the most of the water flow. The easy thing to remember is water will take the easiest root and I would have said that on Cloud Inspectors setup with a bit of calorifier pipework to engine mods it would work alot better. Please not this is all based on what I can see in the pics, I would need to work out the whole system to be sure.

Edited October 27, 2015 by martyn 1

[Cloudinspector]

I've fully got my head round how my system works now. Coolant flows through the block to top rail and exits both at both ends. One end to thermostat then bypass circuit and/or skin tank. The other end is hot water into the calorifier which exits into the bypass pipe via t piece.

 

This pipe feeds hot water into calorifier

 

 

The t piece is the return from the calorifier into the bypass pipe.

 

 

Would my system be more efficient if it was plumbed the same as mark 99?

The difference as I see it is there's a possibility marks calorifier circuit will be cut off when the thermostat closes off the bypass circuit whereas mine will always have hot water fed into it with a less efficient flow?

[Split Pin]

As Martyn indicated the best way to connect a calorifier is to remove the bypass pipe and insert the calorifier coil circuit in its place.

This ensures that water is circulated through the block and head and along the top rail to the thermostat, giving proper temperature control.

By taking the hot water from the rear of the rail there is a non temperature controlled circuit being established, with the potential of water flowing in both directions from the top rail.

It may be that when the thermostat opens that the flow will go round the skin tanks as they are probably the path of least resistance.

To guarantee that you are heating the calorifier you could either change the thermostat for one without the top hat that blanks the bypass when open or remove the top hat from your current one.

 

Steve

[mark99]

Cloud Inspector - see picture below of my bypass circuit - it keeps flowing when thermo off. My bypass circuit goes via my calorifier. (See below for feed return from calorifier).

 

As Martyn indicated the best way to connect a calorifier is to remove the bypass pipe and insert the calorifier coil circuit in its place.

This ensures that water is circulated through the block and head and along the top rail to the thermostat, giving proper temperature control.

By taking the hot water from the rear of the rail there is a non temperature controlled circuit being established, with the potential of water flowing in both directions from the top rail.

It may be that when the thermostat opens that the flow will go round the skin tanks as they are probably the path of least resistance.

To guarantee that you are heating the calorifier you could either change the thermostat for one without the top hat that blanks the bypass when open or remove the top hat from your current one.

 

Steve

 

 

Thanks SP - that's exactly the point I've been trying to get to bottom of/validate - the pump can be setting up a null point in the cooling bypass circuit if connected both ends of header.

[Cloudinspector]

Cloud Inspector - see picture below of my bypass circuit - it keeps flowing when thermo off. My bypass circuit goes via my calorifier. (See below for feed return from calorifier).

 

 

 

 

Thanks SP - that's exactly the point I've been trying to get to bottom of/validate - the pump can be setting up a null point in the cooling bypass circuit if connected both ends of header.

It makes sense that substituting the bypass circuit with the calorifier is the preferred option and I'd more or less come to that conclusion. This info has confirmed it for me. Thankfully I don't rely on the engine for hot water as we have a diesel range which means we tend to have hot water available all the time.

However I will be altering the plumbing at the first opportunity.

[steamraiser2]

I see that Martyn has beaten me to it , which is a surprise as he is supposed to be looking after Laura who has just presented him with number one son, Thomas. Am I a smug Grandad or what! . Comes to something when you have to start a breeding program for apprentices!

 

Martyn was being lowered into locomotive boilers on a rope as a five year old to shovel out the rust and scale. I bet Thomas is up to his arms in Gardners before he starts school !!!!! ..... must go and find a starter size boiler suit in Mothercare!

 

On a Gardner note:

 

Incidentally I notice that there are quarter turn domestic stop valves in Cloud Inspectors picture. Be careful of using these as many types have a very small bore and can easily block with scale. If you use them make sure you have a corrosion inhibitor in your cooling system.

[Split Pin]

 

On a Gardner note:

 

Incidentally I notice that there are quarter turn domestic stop valves in Cloud Inspectors picture. Be careful of using these as many types have a very small bore and can easily block with scale. If you use them make sure you have a corrosion inhibitor in your cooling system.

Cloudinspector if you re-plumb it might be better to take the quarter tun valves out completely, no chance then of turning of the bypass accidentally.

 

Looking back at the previous topic which started this debate you haven't said if you made the original system work again,

I have always found it necessary to vent out the air from the top rail especially if the header tank is not connected directly to and above the top rail with the pipework running up from the top rail,

Adding a bleed vent to the top rail would be a worthwhile addition,

If your thermostat doesn't have a jiggle pin then you will need to bleed out air from the block when the system has been separated and refilled.

Even with a jiggle pin it takes a long time to release all of the air. assuming it has some where to go on the other side of the thermostat

Gardner's recommended that the air bleed be reduced to 1mm dia on marine applications to speed up the warm up time.

 

Steve

[LEO]

I see that Martyn has beaten me to it , which is a surprise as he is supposed to be looking after Laura who has just presented him with number one son, Thomas. Am I a smug Grandad or what! . Comes to something when you have to start a breeding program for apprentices!

 

Martyn was being lowered into locomotive boilers on a rope as a five year old to shovel out the rust and scale. I bet Thomas is up to his arms in Gardners before he starts school !!!!! ..... must go and find a starter size boiler suit in Mothercare!

 

On a Gardner note:

 

Incidentally I notice that there are quarter turn domestic stop valves in Cloud Inspectors picture. Be careful of using these as many types have a very small bore and can easily block with scale. If you use them make sure you have a corrosion inhibitor in your cooling system.

 

Hi

 

Congratulations. I guess he will be called LW or perhaps Paticroft.....

[Cloudinspector]

Cloudinspector if you re-plumb it might be better to take the quarter tun valves out completely, no chance then of turning of the bypass accidentally.

 

Looking back at the previous topic which started this debate you haven't said if you made the original system work again,

I have always found it necessary to vent out the air from the top rail especially if the header tank is not connected directly to and above the top rail with the pipework running up from the top rail,

Adding a bleed vent to the top rail would be a worthwhile addition,

If your thermostat doesn't have a jiggle pin then you will need to bleed out air from the block when the system has been separated and refilled.

Even with a jiggle pin it takes a long time to release all of the air. assuming it has some where to go on the other side of the thermostat

Gardner's recommended that the air bleed be reduced to 1mm dia on marine applications to speed up the warm up time.

 

Steve[/quote

I've had some success by connecting a hose onto the calorifier circuit and forcing the air out by tap water pressure. Because I misunderstood which way the hot water was flowing into the calorifier the inlet is connected to the outlet. Swapping these round will hopefully aid flow.

[LEO]

 

Hi

 

well you've shown me yours so I had better show you mine!.

 

The 15mm pipe (bottom left) with the red gate valve is from the calorifier.

 

The thick copper pipe (rear of starter motor) is from the skin tank.

 

The thick copper pipe running along the wall (below) the fuel filter connects to the Thermostat housing.

 

 

 

 

 

The 15mm copper connects to the calorifier.

 

This system gives a quick warm up and the engine runs at a good even temperature.

 

Must get the Brasso out, but am about to embark on a major undertaking - changing the coolant, no drain tap so it's a messy job.

 

Paintwork on the block is peeling off so some de-greasing and repainting work will be carried out at the same time.

 

Engine overhauled and installed about 2002, the red air filter (and peeling paint) indicates who restored the engine, it's not a 'polished' version.

 

Mike.

Edited October 28, 2015 by LEO

[mark99]

Mike your's is same, effectively as Cloud Inspectors.

[by'eck]

Problem with LEO's setup is that calorifier receives heat from engine immediately after start-up which may be regarded as a good idea but must inevitably slow engine warm up. Better that thermostat bypass circuit be engineered so that calorifier is completely out of circuit until engine reaches operating temperature before bypass is routed through calorifier coil. This can be achieved with manually operated T port valve or better still automated with second thermostat.

[Split Pin]

Problem with LEO's setup is that calorifier receives heat from engine immediately after start-up which may be regarded as a good idea but must inevitably slow engine warm up. Better that thermostat bypass circuit be engineered so that calorifier is completely out of circuit until engine reaches operating temperature before bypass is routed through calorifier coil. This can be achieved with manually operated T port valve or better still automated with second thermostat.

 

It would seem that using either of the methods that you suggest would be better, but in reality it doesn't work.I spent more hours than I care to think about trying different ways of controlling the hot water flow through the calorifier coil non actually reduced the overall warm up time.

I built a electrically controlled by pass control vale which would open when the temperature got to about 10 deg below thermostat temperature, when it opened the engine temperature was pulled back down due to the heat lost in the calorifier circuit. It required a differential setting of at least 30 deg C to get it stop open.

The same problem will be encountered using a second thermostat,

It is of course always worst when staring up from cold, (first start up) once into daily cruising there is enough retained heat in the calorifier to assist in the initial warm up period, the biggest problem with warm up time is caused by the fact that in narrowboats the engine is not sufficiently loaded to generate the heat and there is around 1/4 ton of metal to heat up as well.

 

Steve

[LEO]

 

It would seem that using either of the methods that you suggest would be better, but in reality it doesn't work.I spent more hours than I care to think about trying different ways of controlling the hot water flow through the calorifier coil non actually reduced the overall warm up time.

I built a electrically controlled by pass control vale which would open when the temperature got to about 10 deg below thermostat temperature, when it opened the engine temperature was pulled back down due to the heat lost in the calorifier circuit. It required a differential setting of at least 30 deg C to get it stop open.

The same problem will be encountered using a second thermostat,

It is of course always worst when staring up from cold, (first start up) once into daily cruising there is enough retained heat in the calorifier to assist in the initial warm up period, the biggest problem with warm up time is caused by the fact that in narrowboats the engine is not sufficiently loaded to generate the heat and there is around 1/4 ton of metal to heat up as well.

 

Steve

 

 

Hi,

 

If a quick warm up required would closing the gate valve (in Picture) close off the calorifier circuit?.

 

In it's present form the engine is warm and hot water is available from the calorifier within about 15 mins running under load.

 

The cooling system is vented and not sealed and the thermostat on the top rail runs within manufacturers tolerances.

 

Mike,

 

Gardener Engine Forum magazine as good as ever.

[by'eck]

 

It would seem that using either of the methods that you suggest would be better, but in reality it doesn't work.I spent more hours than I care to think about trying different ways of controlling the hot water flow through the calorifier coil non actually reduced the overall warm up time.

I built a electrically controlled by pass control vale which would open when the temperature got to about 10 deg below thermostat temperature, when it opened the engine temperature was pulled back down due to the heat lost in the calorifier circuit. It required a differential setting of at least 30 deg C to get it stop open.

The same problem will be encountered using a second thermostat,

It is of course always worst when staring up from cold, (first start up) once into daily cruising there is enough retained heat in the calorifier to assist in the initial warm up period, the biggest problem with warm up time is caused by the fact that in narrowboats the engine is not sufficiently loaded to generate the heat and there is around 1/4 ton of metal to heat up as well.

 

Steve

 

Well it certainly works for me using a T port valve on my JP2 to positively direct bypass direct to pump inlet or via calorifier coil and it definately aids warm up.

 

Barrus Shire might disagree with the twin thremostat setup they use on their larger engines.

 

 

In fact many/most larger marine diesels have a twin thermostat setup to allow for engine coolant water heating circuit. The TMD31B Volvo on my last boat for example.