Cooling

[gdr]

Poured in 2 bottles of Water Wetter. Dropped stable idling water temp (with fans on) from 95 deg C to 85 deg C just like that. Remarkable.

[Stig]

gdr said: Poured in 2 bottles of Water Wetter. Dropped stable idling water temp (with fans on) from 95 deg C to 85 deg C just like that. Remarkable.

Did you add the Water Wetter to an antifreeze/water mix or was it plain water?

I tried 2 bottles of water wetter in mine and it still overheated?

[GTRCLIVE]

Did a Cruise down the Kings road on Sunday, highest temp was 92C when stationary. Water only. Have you decided what you are going to fitt yet Bud ?

[Stig]

Have fitted the Davies Craig (keep wanting to type Craig Davies - arrghh!!! Can't stand the crooning muppet) EWP and oil cooler fan. Improvement, but still not there yet.

2 new Pacet 10" profans arriving today which have twice the airflow than the standard fans.

If that doesn't work then err... will remove mesh in bonnet behind rad. Put some more open stuff in like the mesh in front of the rad.

PS. Edited to say that there's an update on my site with all the details

>> Edited by Stig (moderator) on Wednesday 28th May 10:17

[gdr]

Did you add the Water Wetter to an antifreeze/water mix or was it plain water?

I tried 2 bottles of water wetter in mine and it still overheated?

---

I am using a red coolant premix from Comma, can't remember brand name, glycol and some sort of corrosion inhibitor I think. WW meant to be better with plain water if label to be believed, but seems to have worked ok for me. Have you used 2 bottles of WW? Volume of Ultima cooling system must be about 25-30 litres.

[Miraz]

Aplogies for a dumb question - I'm trying to understand the location that Stig has used for the EWP.

Does anyone have a diagram of the cooling system that shows the relative positions of the stock water pump, swirl pot, bypass circuit and radiator circuit?

>> Edited by Miraz on Wednesday 28th May 11:11

[Stig]

Miraz said: Aplogies for a dumb question - I'm trying to understand the location that Stig has used for the EWP.

Does anyone have a diagram of the cooling system that shows the relative positions of the stock water pump, swirl pot, bypass circuit and radiator circuit?

>> Edited by Miraz on Wednesday 28th May 11:11

Miraz,

The coolant flows out from the top manifold outlet, into the swirlpot, down (through the EWP) into the left hand cooling pipe, into the top of the rad, out of the bottom of the rad, along the right hand pipe, into the water pump, around the block, then up and out again.

[Miraz]

Have you measured the temperature gradient across the engine?

If you developing a significant temp gradient (more than 10 celsius) then you need to do more work on pumping coolant - if the coolant is moving fast enough to keep everything at the same temperature then the pushing more air through the radiator is the way forwards.

>> Edited by Miraz on Wednesday 28th May 11:56

>> Edited by Miraz on Wednesday 28th May 12:07

[ultimasimon]

Chris; were did you get your Pacet 8" fan, and both your hi-flow radiator fans? Don't suppose you would happen to have a price and a part number would you?

Cheers Simon.

[jschwartz]

Removing that restrictive grill behind the rad may help. I'd bet if you removed the blower she'd cool just fine.
How about spraying some NOS across the radiator like the "Fast and Furious" crowd does with their intercoolers?

[Alan 2]

Stig. I am wondering if your EWP will actually increase the coolant flow rate through the system bearing in mind that it is in series with the mechanical pump. It would seem to me that the controlling factor in respect of coolant flow must be the speed of the impeller on the mechanical pump. If this impeller is going slowly (when the engine is idling) then the fact that the EWP is revolving its head off, may not make that much difference. It's some time since I had a mechanical water pump in bits but as far as I remember, there isn't very much clearance between the impeller vanes and the housing so you can't really force water through it, if you see what I mean.

The early Mark 4 Sports had serious overheating problems in traffic so I went to a lot of trouble to ensure that mine didn't. Most significantly, I plumbed in a second radiator in the o/s side pod with a 10" fan (with all the extra pipework involved, this also added an extra 4 litres or so to the total volume of coolant). I also fitted two 9" extraction fans either side of the gearbox to pull hot air out of the engine bay. These really work. I also have an EWP as well as a high performance mechanical pump. However, by far the most important reason that my car doesn't overheat is the fact that it doesn't have a 600hp supercharged engine.

Apologies for the not very helpful comments but I think that what you really need is more radiator area, more coolant and more fans.

[stig]

Alan 2 said: Stig. I am wondering if your EWP will actually increase the coolant flow rate through the system bearing in mind that it is in series with the mechanical pump. It would seem to me that the controlling factor in respect of coolant flow must be the speed of the impeller on the mechanical pump. If this impeller is going slowly (when the engine is idling) then the fact that the EWP is revolving its head off, may not make that much difference. It's some time since I had a mechanical water pump in bits but as far as I remember, there isn't very much clearance between the impeller vanes and the housing so you can't really force water through it, if you see what I mean.

The early Mark 4 Sports had serious overheating problems in traffic so I went to a lot of trouble to ensure that mine didn't. Most significantly, I plumbed in a second radiator in the o/s side pod with a 10" fan (with all the extra pipework involved, this also added an extra 4 litres or so to the total volume of coolant). I also fitted two 9" extraction fans either side of the gearbox to pull hot air out of the engine bay. These really work. I also have an EWP as well as a high performance mechanical pump. However, by far the most important reason that my car doesn't overheat is the fact that it doesn't have a 600hp supercharged engine.

Apologies for the not very helpful comments but I think that what you really need is more radiator area, more coolant and more fans.

Err... somewhat contradictory comments Alan seeing as you have fitted an EWP?

Regarding the additional rad, it's not an option seeing as both pod grills are filled (n/s oil cooler and o/s air con) but at least they both have fans which help draw cooler air into the engine bay.

The uprated fans which I got today flow 2180 CFM of air combined compared to 1150 with the current setup - that's a significant increase.

I thought about fans to draw air out of the engine bay, but the heat tends to hang around in the top of the canopy where the 'charger sits. If I mounted them by the gearbox the air would just come from the area of least resistance and would do sweet f.a. above the headers.

Anyway, thanks for your input and as I said earlier, I think the solution will consist of several small fixes, rather than one big cure-all.

[k wright]

Another option is that of using four returns from the four corners of the intake manifold. This increases the amount of water that circulates by the rear cylinders and evens out the temp throughout the heads. I think that CSI makes and adapter that mates the -8 hose size (four of them) to the radiator hose size. www.csiperformance.com/cooling_5.html

I think that adding an elctric water pump in series with the mechanical one will not be an exercise in futility. The mechanical pump is not a positive displacement pump. It is possible for coolant to flow right by it even when it is at a dead stop.

ken

>> Edited by k wright on Thursday 29th May 15:55

[Stig]

Having a sense of humour failure now

Fitted the high performance fans today, but, still no joy. The car took about 35 minutes to get to 100 degrees and didn't look like stopping - so I shut it down.

Next 'fix' was to remove the grill mesh from behind the rads, the result - again, the temperture only goes up, no down.

So, convinced myself that the EWP may be restrictive, so I remove it and re-fit the standard pipework - again, no joy.

So I'm a bit stuck now? I've doubled the volume of air cooling the rad, I've improved the airflow to get the heat away from the fans and I've made sure that the coolant is circulating properly and I've got a hi-performance fan cooling the oil cooler.

I tried at low idle, high idle, every damn idle.

I tried with the heater on (the last run it made a rather ill sounding rattle and now appears to have seized ) off, aircon on/off, you name it.

The only good thing was that today, being so hot, means that it was a realistic test for a summer traffic jam.

However, it's no good if the car still can't cool itself

Bugger.

[GreenV8S]

All I can suggest at this point is that you measure the temperatures across the rad. Air and water, upstream and downstream. This will require four remote sensing thermometers which you can buy from Maplins for about £10 each. Once you know the air and water temperatures in and out of the rad it is possible to work out what is limiting the cooling system.

[jay esterer]

Hi Stig
was the EWP noisy? I bought one for my car (the stock v12 WP is pathetic)
When I have had the type of cooling problems you are having on my past projects I have resorted to extreme
measures. I start adding methonol to the gas,10%,30%,
what ever it takes. Methanol and blowers go very well together. Of course you have to run 10 to 30% more fuel to the motor and methonol is more corrorive than gas. It will solve the cooling issue and potentially cause other ones.

[Alan 2]

stig said:

Err... somewhat contradictory comments Alan seeing as you have fitted an EWP?

---

Not really contradictory as I didn't fit the EWP in the same way that you did.

My EWP is in parallel with the mechanical pump rather than in series with it. This means that under normal operating conditions, coolant from the engine goes straight through the swirl pot along the n/s pipe and into the radiator just as in the standard set up. It does not have to go through the EWP as it does in your car. I did think about doing it your way but didn't know if it would then be necessary to run the EWP all the time (which is not recommended), in order to guarantee a sufficient flow of coolant. I tried to find out how easily the EWP impeller would "freewheel" when the pump was switched off so that coolant, driven along by the mechanical pump, could pass through it more or less unhindered but nobody seemed to know.

I finally decided to install my EWP on a by-pass, with the intake being just below the swirl pot and to use a simple on/off switch to control it. It was intended to provide a boost to the coolant flow when things got really desperate but fortunately, I have never had to use it. I am putting a GTR together at the moment and intend to build all of the cooling mods which are in my Sports into the new car; except for the EWP which I don't think is necessary.

I have some photos of the various cooling mods I built into my Sports, which I would be happy to E-mail to anyone who may be interested. I am not saying that this is the way everyone should go, only that these mods seem to work for me. But, and it's a big but, my 350 Chevvy is a standard ZZ3 HO engine dynoed at 332BHP. I do have aircon, with the condenser fitted in front of the main radiator, (which doesn't help engine cooling) and I have also panelled the underside of the engine bay against the factory's advice, which again, doesn't help engine cooling.

Like most of the folks posting to this forum, just trying to be helpful to other Ultima enthusiasts.