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View Full Version : Liquid cooling, part 2



letterman7
16-11-2009, 01:27 AM
I didn't want to highjack Ben's thread about rad placement, as this is along another assembly line... literally! This question stems from being completely boneheaded about the basics of engine cooling. From my build post above, I've pulled the water pump assembly from the motor, since the shaft was frozen up solid from years of rust and corrosion:
http://i16.photobucket.com/albums/b31/letterman7/SNR%20build/NRenginenaked.jpg
You can see the housing right below the engine. The bright circle in the middle was where the actual bearing shaft was, and the bright spot to the right is where one of the water necks fit (more on that). The other water neck is on the upper intake manifold whaich you can just see dead center with the three studs sticking up. Now... there was no thermostat in place - this was a California car. Which way does the water actually flow into and back out of the block? Does it enter from the lower right and exit out the top of the block?
The reason I'm asking is I'm trying to figure out the hose connections on the lower water neck. On the back of the block there is a 90 degree neck (seen as the dark spot in the water passage in the lower right corner), on the now very corroded water neck there are two more necks - one the same size as the block neck (about an inch and a quarter wide) and one small neck (about a half inch). I'm figuring one or two of those had to fit a heater - the smaller of the two necks was blocked off with a plugged piece of hose, and, come to think of it, one of the big necks was blocked, too. Somehow it doesn't make 'flow' sense to me that the heater core would be right on the inlet to the engine, but having never taken one apart I can't be sure.
The other thing I wanted to check was this: instead of putting a new water pump assembly on, is it possible to simply weld closed the bearing shaft hole and use an electric pump on the inflow side (and, if needed, on the outflow)? Not having the bearing neck and pulley will actually save me a couple of valuable inches in interior space, so long as I can set the other accessory pulleys correctly. Can anyone see any issues with that particular setup?

Big Birds Car
16-11-2009, 08:45 AM
If no-body comes up with the answers I will see if there is anything in my Ford Granada manual that shows the water system (My Granada had the 2.8 cologne engine in it). If memory serves I think you had the main radiator hose going in at the top of the inlet manifold, there would have been a heater hose as well somewhere up there. The bottom radiator hose I think was out the front of the water pump (thermostat bit) and a heater hose somewhere there as well and there may well have been another reasonably sized hose that went from the back of the water pump area to the expansion tank/header tank.
Can't see why electric water pumps couldn't work so long as it can push the volume of water required at a constant rate.

nbb350
16-11-2009, 05:19 PM
Factory setup:
Coolant comes into the pump from the lower 1 1/4" radiator hose (cold coolant falling thru the radiator) AND from the 1/2" heater hose - this path is shown at the "4 o'clock" position. It comes into the center of the pump. Coolant in centrifugal pump is sucked in at the center and spun outwards to the channels leading to the engine block - small rectuangular holes at ends of spiral channels on either side of pump. Coolant passes thru the block/heads and into the intake manifold. HOT Coolant splits into a small heater outlet (1/2") and then thru the Thermostat and into the upper radiator hose. There is often also a small (~3/8") bypass channel next to the thermostat housing - this should NOT be blocked since you need some coolant to be able to pass by so that your pump isn't trying to create a vacuum in it's inlet side. Especially important if you have the heater hose blocked off. Instead of blocking off the heater hose though, if you're not installing a heater core, just loop the heater outlet to the heater inlet with a chunk of hose.

Modified setup:
Weld the cover plate over the bearing shaft opening. In the lower radiator hose between radiator and engine block, install an electric coolant pump. Placing it here mimics the factory design: the coolant is PUSHED thru the engine instead of being PULLED thru if the pump was on the upper radiator hose.

Buy something designed for the task, like this:
http://www.summitracing.com/parts/FMS-M-8501-L54/ (hose size??)
http://www.summitracing.com/parts/PRO-66225BK/ (will need custom ends machined & welded. this is what I did)
http://www.summitracing.com/parts/MEZ-WP136S/ (only 20gpm)

letterman7
16-11-2009, 05:27 PM
Ah... ok, that's what I was thinking it was. I'll have to double check to see if there is an actual heater bypass on the upper water neck. Since it's an aftermarket manifold, I don't remember seeing one in the neck, but I didn't look that hard, either. I have to replace it anyway...

Good idea with pushing the water, too. I was and still am tempted to put a push/pull system in (two pumps) just in case...one fails. Or maybe just carry one as a spare!

Spacenut
16-11-2009, 07:52 PM
Hi Rick - see "New Life" post for exactly what you are suggesting (replace mechanical water pump with electric). Great minds and all that :D

As far as the heater matrix is concerned, the heater core should be connected between the flow and return before the thermostat, i.e. when the engine is cold and the thermostat is closed, there will be no flow through the radiator, just from the water pump back to the engine. This speeds up the warming process. The heater core should be connected between these two points, otherwise the heater will stay cold until the thermostat opens, which in Winter could be quite a while!

Looking at the impellor configuration (the arrangement of serpentine casting in the block), the thermostat housing on the right is in the return feed from the block. I am hoping that one of your smallbore water outlets is accessible at this point, and that there is another inlet stub on the other side of the impellor (the "compression" side, if you like). This would allow the heater core to warm up even with the thermostat closed.

Just guesswork on my part, but it might help. If you do go down the electric pump route you need to push coolant into the two cylinder waterways, and extract the return flow from the thermostat housing at lower right. Hopefully the electric pump will be one with an integral thermostat (i.e. for road use not drag racing), so you can simply block off the appropriate ports with a suitable blanking plate.

Lauren

Spacenut
16-11-2009, 07:55 PM
Actually, Nbb said it all, serves me right for not reading the whole post through! :dunce:

Lauren

nbb350
16-11-2009, 08:39 PM
Maybe I should also add: the aforesaid is correct in regards to most GM small block v8 engines. I don't work on Ford or Mopar...or any imports (from an American point of view!). I think the theory I outlined holds water (er...coolant?) for most general cooling systems though...with a few minor variations between manufacturers.

Lauren, I know the casting on the lower right looks like it would take a thermostat, but it also looks like his thermostat could be up in the front-center of the intake manifold? without one in place originally, it's hard to tell...

Big Birds Car
16-11-2009, 09:10 PM
Lauren, I know the casting on the lower right looks like it would take a thermostat, but it also looks like his thermostat could be up in the front-center of the intake manifold? without one in place originally, it's hard to tell...

NBB
The thermostat on the Cologne is in the water pump housing and not on the inlet maifold on the top. Yes odd but true. Ihaven't been able to locate the Granada manual but did find a Sierra one that shows the thermostat. I will try to scan it tomorrow if it is of any use.

letterman7
16-11-2009, 09:43 PM
Lauren, I know the casting on the lower right looks like it would take a thermostat, but it also looks like his thermostat could be up in the front-center of the intake manifold? without one in place originally, it's hard to tell...

NBB
The thermostat on the Cologne is in the water pump housing and not on the inlet maifold on the top. Yes odd but true. Ihaven't been able to locate the Granada manual but did find a Sierra one that shows the thermostat. I will try to scan it tomorrow if it is of any use.

That's where I thought it was. The top most housing looked too small for a T-stat. I'll have to get a Bentley for a Mustang II sometime soon!

Spacenut
17-11-2009, 07:04 PM
I know the casting on the lower right looks like it would take a thermostat, but it also looks like his thermostat could be up in the front-center of the intake manifold? without one in place originally, it's hard to tell...

:oops2:

You're right.

I'm not being very observant am I?

:blushing:

nbb350
17-11-2009, 07:24 PM
I'm not being very observant am I? :blushing:

eh...I didn't even notice the lower port could take a thermostat until YOU mentioned it... :whistling:

letterman7
14-05-2010, 09:06 PM
Am I overthinking this?
I put the final pieces of the plumbing in place today, hooked up the pump and filled the system with water to test for leaks (none - thankfully!). But it occured to me that the way I had it plumbed initially, with the pump forcing water in from the bottom of the block and out the top wouldn't circulate the water, since the t-stat would be closed anyway. The water would be basically stagnant in the block. So, I swapped the pump fittings, and now I'm forcing the water in from the top and (eventually) out the bottom when the 'stat opens.


http://i16.photobucket.com/albums/b31/letterman7/SNR%20build/NRplumbing.jpg

However...and I may be panicking prematurely, hence my asking here: in theory, the "recirculating hose" - Ford's doing, not mine - does not seem to be doing just that. I have pressure at the pump side (water exits the hose at the block), but if I pull the heater hose off the very top fitting, nothing comes out, even though the block is filled with water. I can add water to that heater hose if I hold it high enough, and if the radiator cap is off, it will back-overflow out of there, then eventually out the block fitting. Now... the only thing I can think of is that since there is no "open" system, really, then the water is still stagnant until the t-stat opens, which hopefully will happen as the water in the block heats up. I'm sure there are some air pockets; I can squeeze the hoses and hear gurgles.
With the OEM water pump, the pump would pull the water around in circles in the block I'm assuming until the t-stat opened, wouldn't it? I'm hoping to fire the engine up again this weekend, but I want to make sure I'm not going to cook anything - I don't have a temp gauge in place yet (maybe I should get a cheap one!). But I want to run the engine long enough to heat the water to see that everything circulates right and to purge some of the air bubbles.

Should I worry? Should I maybe drill a small hole in the t-stat housing just to get some water to flow?

Spacenut
14-05-2010, 09:56 PM
Hmmm - I would at the very least jury-rig a temperature guage before running the engine for any length of time. My original 1.5 Ti engine would still be here today if I had done that; instead, I ran the engine until I noticed the coolant boiling in the header tank (the thermostat had stuck closed), and the cylinder block was cracked.

I agree with you - the coolant should not be stagnant in the block during warm-up. It must be allowed to circulate through the block. The thermostat normally sits at the top of the block so that convection heat migrates to it. Conversely, cooler water from the radiator is fed into the bottom of the block. Hopefully the location of the appropriate inlet and outlet stubs will give you the clue to the circulation direction.

I am curious as to why the bypass hose is stagnant with the thermostat closed. I think if you are at all concerned it might be safer to run the engine without the thermostat altogether. It may take a little longer to get up to temperature, but at least it shouldn't overheat - unless the block is badly silted up. Either way, a temporary temperture guage is good insurance. Good luck!

Lauren

Spacenut
14-05-2010, 10:25 PM
Just dug out my Cortina MkIV data manual - the 2.3 Litre V6 is a Cologne unit. Neither the engine section or the cooling section are particularly helpful, as neither show the cooling system in-situ, but the thermostat housing is connected to the bottom hose of the radiator. Also, the heater return hose is connected to the thermostat housing. I can't tell anything else from the manual, but I think you are on the right track.

Lauren

bushboy
14-05-2010, 10:33 PM
think you will find that the cold water will allways be drawn from the bottom of the radiator & "sucked into the water pump from the lowest large fitting. The hot water will exit the engine from the highest large fitting & enter the radiator at the highest point. This way, even if the radiator is only 1/2 full the pump will always be drawing water. The coil/spring on the thermo stat is always on the hot side. ie it will point into the block. As it is heated by the hot engine water it will open, allowing the water to pass through the radiator.

For the test, fit clear hoses to the recirculate & heater hoses so you can see what is going on. On the Mazda V6 in the reek the heater hose acts as the recirculate hose.

If you are unsure about the thermostat then as Lauren has said, leave it out for the test. Any holes you drill in castings will have to be filled later.

Best of luck & a video with sound of the beast running would be nice :clapping: :clapping:

bushboy

bushboy
14-05-2010, 10:43 PM
Try this link for a picture that may help.

http://www.google.co.uk/imgres?imgurl=h ... s%3Disch:1 (http://www.google.co.uk/imgres?imgurl=http://www.fordscorpio.co.uk/images/coolantcosch.jpg&imgrefurl=http://www.fordscorpio.co.uk/leaks.htm&usg=__RZJbUUP3ZhwJENEONgpAl0tpEjw=&h=756&w=577&sz=62&hl=en&start=23&um=1&itbs=1&tbnid=ANcVDp4gapLgaM:&tbnh=142&tbnw=108&prev=/images%3Fq%3Dcologne%2Bv6%2Bcooling%26start%3D20%2 6um%3D1%26hl%3Den%26sa%3DN%26ndsp%3D20%26tbs%3Disc h:1)

bushboy

letterman7
15-05-2010, 12:23 AM
I've got the manual for the basic engine, and the cooling section is very vague. The orientation of the hoses for the heater and recirc system are where they are shown in the manual, but oddly, I could not find the "right" hose for the recirc system to fit. There must be something intermediate when the engine is in a production car. The heater hose is what it is and will be replaced once a true heater gets installed.
I thought about the feed orientation, BB. With an electric pump it will always be drawing off the bottom of the radiator anyway, so I'm thinking if I remove the t-stat, the actual flow direction won't matter, so long as the radiator is fed from the top and drained from the bottom. My biggest worry with removing the t-stat is that the engine won't get up to temperature, and that may be worse yet for it. Oy....I've some thinking to do tonight!

Big Birds Car
15-05-2010, 10:15 AM
With regards the thermostat, you could leave it in place but drill a couple of extra holes in to ensure that if it doesn't open there is still passage of water, there is usually a bleed hole in them to ensure there is no air locks in that area but a few extra wouldn't harm. Alternatively get a thermostat that opens at a lower temperature, I think you can get ones down to about 82 degrees Centigrade, can't for the life of me remember what that is in F.
But on the other hand run without for the time being and at any of the shows you attend between now and finally putting the car on the road for good, take a look at other cars, modified or standard engines, and seehow they are hooked up.
Drawing from the bottom and pushing through the block is the way I would go.

Spacenut
15-05-2010, 05:42 PM
You gotta admit, these guys are good :D

Don't forget though, the thermostat is really only there to assist in engine warm-up. By keeping the radiator out of the loop the engine gets up to its working temperature more quickly. The thermostat does not "regulate" the engine temperature in normal operation - its just wide open all the time. Temperature control of the engine then passes to the thermostatic radiator fan.

So if you remove the thermostat altogether, the 5 minutes the engine took to get to temperature may extend to 10, or maybe 15. I don't think you will do any lasting damage if you aren't caning the living daylights out of it. I suspect initially you will be idling in the driveway checking which hose gets warm where, and looking for leaks under pressure. That should be no problem at all. Once you are satisfied that the flow control and direction are OK, then you can drain down the system again and refit the thermostat (is it new? Using a 25 year old one that hadn't been operated for 10 years is what killed my engine :bye2: ).

Good luck with whatever you decide to do. I'm looking forward to seeing (and hearing) the results!

Lauren

letterman7
15-05-2010, 05:52 PM
Thanks all, for the suggestions. I removed the t-stat this morning and re-assembled everything, this time with the hoses going in the "stock" direction. We have circulation! I'll have to do some more research about not running a t-stat (and it is a new one); from what I've read most people discourage it as they suggest the engine will never come up to temperature and thusly impart a hardship to the oil and moving parts that require the higher operating temp. I had thought, since my water pump would be switched anyway, I could simply leave it off until the temp sensor read around 150 degrees, but then I might crack the block once it was turned on and that cold water hit it!

I'm sorting some wiring and starter issues right now, so hopefully we'll have ignition soon!

bushboy
15-05-2010, 08:10 PM
Davis Craig do an electric water pump replacement & also sell a box of tricks that will vary the pump speed according to engine temp. With this system the engine does not need to have the t-stat. So to avoid a gut full of cold water hitting the block when you turn the tump on you could have it wired up for two or more speed. Run a PW modulator & you can vary it all the way to full speed.

Bushboy

Spacenut
17-05-2010, 01:09 PM
That sounds like a neat idea. I would tend to agree that the coolant should circulate all the time, but varying the circulation speed seems like the best approach. Although when you consider that a fair old gulp of cold water will be received when the thermostat opens for the first time (little holes notwithstanding), its fairly clear that the thermal shock margins are quite high :D

I'm still not convinced by this argument that the thermostat somehow regulates the engine temperature. I've got a thermostat that opens at 78°C in my Alfa engine. The thermofan switch kicks in at 88°C. So there is only 10°C of control margin in this loop. That's just not enough to be effective. So unless you live in the Arctic and the thermostat is permanently closed, there is no regulation of the coolant temperature from this device.

The reason an electric pump can replace the thermostat is during warm-up, by restricting the flow of coolant through the radiator until the block has reached its optimum operating temperature.

Lauren

Big Birds Car
17-05-2010, 06:07 PM
If the block and heads are cast iron I doubt thermal shock will be much of an issue, if alli then yes, more problematic. MGF's and Lotus Elise suffer badly with this from the thermostat opening and closing and cold water suddenly rushing in from the front of the car. It is a known issue and has a couple of different ways of overcomming it. Cast iron will take the shocks with less issues.
Lauren, remember years ago there wasn't electric fans to help cool engines and the thermostat was the only way of slowing up or increasing the water flow through the radiator as everything else was basically constant ie, water pump speeds and usually the fan was attched to the front of the water pump, sit in traffic and you would heat up so the thermostat would open fully, get on a motorway and you could end up cooling too much unless you reduced the water flow hence the thermostat would alter the water flow characteristics. With electric fans a thermostat isn't accurate enough to do the job efficiently so a more accurate "switch" is needed, so with an electric fan set up the thermostat only helps quick warm up and the fans and switch do the rest.

letterman7
17-05-2010, 06:11 PM
I'm loving the idea of an adjustable speed pump. I'll have to look into that idea a little more as the car gets closer to completion. Thanks for the ideas!! :group:

Spacenut
17-05-2010, 09:11 PM
Lauren, remember years ago there wasn't electric fans to help cool engines and the thermostat was the only way of slowing up or increasing the water flow through the radiator as everything else was basically constant ie, water pump speeds and usually the fan was attched to the front of the water pump, sit in traffic and you would heat up so the thermostat would open fully, get on a motorway and you could end up cooling too much unless you reduced the water flow hence the thermostat would alter the water flow characteristics. With electric fans a thermostat isn't accurate enough to do the job efficiently so a more accurate "switch" is needed, so with an electric fan set up the thermostat only helps quick warm up and the fans and switch do the rest.

Point taken BBC - I guess the Cologne V6 is old enough to remember a fan on the end of the water pump pulley, although it was probably a viscous-coupled unit :clapping:

I suppose I was making the mistake of assuming all engines have the same limited control range, forgetting that the Alfasud was designed from the outset for thermofan control... in 1972 :D

Lauren

Big Birds Car
18-05-2010, 10:26 PM
Well there you go, my 73 Capri had a crappy (no pun intended) 2l V4 that was about as good as a chocolate tea pot, (hence putting the V8 into it) and had nothing that ressembled any sort of electronic features and if you remember the engine had to have an extra shaft fitted into it to stop the rubbish engine from vibrating itself to bits, basically an after thought and not forethought. The Itallians were far and away more advanced on design and technology but had no idea about wiring or keeping a steel body in one piece. :laugh:

Spacenut
20-05-2010, 09:48 PM
Very true BBC. IIRC the Ford V4 was actually a Cologne 60° V6 with two cylinders lopped off so that it would fit in front of the transmission in the Taunus. The same engine and transmission package was used in the rear of the 1964 Mustang prototype. So the balancer shaft was needed to keep the reciprocating mass balance. The technique has been used to better effect on later cars - the Mitsubishi Starion and Porsche 944 notably...

Lauren