High H2O temp. at slow traffic

[srreck]

Comments and solutions about high temp. on slow traffic and stops are welcome. Thanx

[GreenV8S]

Comments and solutions about high temp. on slow traffic and stops are welcome. Thanx

Is your stat working? This must be the first suspect.

Is it actually overheating? Is the gauge accurate? If not, may be worth letting sleeping dogs lie.

Assuming you really do need more cooling, you need to start with some good fans, that are ducted so they draw in cold fresh air (i.e. make sure hot air off the back of the rad can't be sucked in the front again). Water circulation goes up dramatically with revs so if your pump is geared for high revs, it may be turning too slow at tickover to pump enough water to shift the heat. One of the clues is if the engine overheats at tickover but cools better if you hold the revs up to 2000 rpm. (Incidentally, if you do get stuck in traffic and get catastrophic overheating, just picking the revs up gives you a much better chance of avoiding a boil over.) You may be able to increase the gearing to improve low RPM water circulation but make sure it doesn't over-rev at max rpm (allegedly this is why the TVR Le Mans contenders dropped out all those years ago). If you've got plenty of cold air through the rad and can't up the water pump rpm, you could add a Davies Craig wassaname secondary electrical booster pump to help at the bottom end.

If you want to be a little more precise at narrowing down the problem, what you want to measure is the water temperature in the corner of the radiator matrix right where the bottom hose connects. This is a pretty good indication of the relative amounts of air and water going through the rad, which tells you which you need to increase to improve the cooling.

Hope this helps,
Peter Humphries (and a green V8S)

(edited becausde I can'tr speel)

>> Edited by GreenV8S on Monday 24th February 20:58

[G Man]

srreck

I have the same issues, first get "water wetter" it does work.

"www.redlineoil.com/redlineoil/wwti.htm

The heat from the exhaust does not help, try a ceramic coat www.zirotec.com.
www.camcoat.u-net.com/ these guys do an ceramic coat to go on the radiator to improve efficiency

PS Do you have the extra large radiator from Ultima

One Ultima user has installed an electric water pump in parallel with his mechanical one to keep constant water flow

Live in colder country !!!!!!!!

G Man

[adequatespeed]

You could use an electric water pump

www.csiperformance.com

I have one of these on my car and it seems to work a treat.

[srreck]

My stat is opening at 165ºF. The rest of things are in the Ultima usual way. However I have found that the fans switch comes too late (at 192ºF) it means that when fans start to cool the radiator the temp on the heads is close to boiling point. I will replace the fans switch. A temp. strip on the radiator outlet may be a good idea !!.
Does Ultima offer a bigger radiator ? I think that I have the biggest because there is not a free milimeter in the radiator compartment. I was thinking to fit an aluminium core unit and a Stewart Components in line electric pump, or and additional radiator.
Thanks to everybody

[mkoch1]

Another option is to switch to a non-water coolant like NPG + coolant. More info can be found at www.evanscooling.com/main31.htm

Here is some info from an engine builder that uses the coolant
______________________________________________-
General Information
Evans NPG+ is a special waterless coolant with a 375 degreeF boiling point at zero psi and does not freeze until -70 degreesF (it contracts and gets 'slushy'; not really freezes). Because it is non-aqueous (no water), corrosion is virtually eliminated and there is no need to change it yearly. In fact, it has been tested for hundreds of thousands of miles with no signs of degradation, according to Evans. While the initial cost is high, compared to ordinary coolant, it is a bargain over the life of the vehicle.

Ordinary coolants operate at the verge of boiling, which puts them at high risk of localized boiling at hot-spots within the engine, even when coolant temps otherwise appear moderate. Any localized boiling interrupts heat transfer and potentially creates a cycle that leads to overheating (hot spot gets hotter and hotter, until it gets out of hand). Ordinary coolants also require the system to be highly pressurized to raise the boiling point to the required operational temperature. This puts stress on all the cooling system (seals, hoses, etc.) and poses an additional risk of a leak that depresurizes the system and drops the boiling point of the coolant below operational temperatures. Evans NPG+ coolant, on the other hand, can be run at zero pressure and has a remarkably high boiling point of 375 degreesF. Because its boiling point is so high, localized boiling is eliminated and overall heat transfer is greatly improved. What you will notice is (1) your vehicle will get up to operational temperature in about half the time, (2) it will then stay right in the optimum temperature zone even when driven well beyond what ordinary coolants could endure.
___________________________________

You will have to form you own opinion on whether or not to use it. If people want I can post comment from people who are using the stuff.

mark

[ultiman]

Rather than start a new post on the subject of summer cooling, l thought l would look through some old subjects and see what wise words have already been written. l was looking for info and experience on the use of auxillery electric water pumps for slow traffic in hot conditions, but found the non acqueous Evans coolant.
Does anyone have experience of either?
l noticed a TVR owner suggested reasing the revs to make the water pump faster. Ted suggested we try reducing the revs as it gives out less heat. He was correct but if running a lairy cam this may not be an option so l am back at auxillery electric water pumps etc.

[ultimaandy]

Things that have worked in Ultima's before.

-Lower the idle to 750rpm
paul and another had overheating problems in france and it was cured on the spot by lowering from 1000rpm to 750rpm.

-buy the fan override switch from Ultima
I did this and retrospectivelly fitted it, the loom should already be there and it cost about £5.

-Try cooling additives (as GMAN).

-Fit an oil cooler (if not already) this made a big difference on my car to the water temp.

Hope this helps
Andy

[ultiman]

Andy
l was that "Other" with Paul in France. l will tell you the storey one day. lt is the experience of the auxillery water pump l am seeking. Does anyone have any knowledge of these?

[ultimaandy]

Sorry wasn't aiming my answer at you ULTIMAN.......

But since you ask, my advice to you on how to keep your engine cool is to make sure it's running on all 8 cylinders


Sorry couldn't resist! be kind

[james]

ultimaandy said: Things that have worked in Ultima's before.

-Lower the idle to 750rpm
paul and another had overheating problems in france and it was cured on the spot by lowering from 1000rpm to 750rpm.

-buy the fan override switch from Ultima
I did this and retrospectivelly fitted it, the loom should already be there and it cost about £5.

-Try cooling additives (as GMAN).

-Fit an oil cooler (if not already) this made a big difference on my car to the water temp.

Hope this helps
Andy

Andy,

Don't you have your fan thermostatically controlled? If it is, you shouldn't need a manual switch (although it's always a good idea to fit one just in case the thermostat fails).

I agree with you on the oil cooler. Remember that the most important job that the oil does is actually cooling. Your engine has come from a front engined car with a lot more airflow over the sump, and you've fitted it in the back of a car that sits low to the ground, so your're going to get less airflow in that region, and therefore less of a cooling effect.

Also remember that you've got the engine producing a lot more power than it was originally designed to, and so it'll be putting more heat into the oil in the first place. An oil cooler is a must.

James

[srreck]

Thank you everybody. Problems has been solved. They were caused by a wrong water pump. Finally fitted a new one with a better flow rate. I installed a manual fan switch as well. For those to think about auxiliary electric Wat.pumps take a look at www.stewartcomponents.com
Interesting site.
Cheers

[ultimaandy]

James
My fans do have thermostat control, its just that it comes in a little later than I would like so I fitted the switch. (I also wanted to move my ignition key and the switch was exactly the right size)

Like you say its a good idea to have the switch even if you never need to use it.

[stig]

Mine has a fan override too. It's a lot easier to keep the heat in control before it's got too hot rather than trying to cool a boiling system!

[james]

The other option is to install a variable thermostatic switch, and you can set it to turn on the fans at the point you require.

[B1 ECC]

I have the bigger rad fitted and have had no problems, I also came up with an idea that seems to work quite well! If you have air-con fitted a'la GTR run a wire through a fuse from the earth side of the front rad fan switch to the earth of the aircon fan, ergo, when the front fan starts so does the air-con fan, blowing the hot air out of the engine compartment. This has double benefits, as when you turn on the air-con the front fans run as well which helps cope with the extra engine load and consequent heat build up.