DAX COOLING SYSTEMS

[Kevin Smith]

I have a Dax with a Super tube chassis and a 327 Chevy.
When using the car in hot weather or in heavy traffic it starts to run very hot. Even with the thermostat removed and both cooling fans running flat out the temperature still remains high.
The conclusion I have come to is that this is caused by poor coolant circulation due to the expansion tank been fitted lower than the top hose/inlet manifold.
Have any of you bloody nice blokes any suggestions or photos of the cooling system lay out on your vehicles.

Many thanks

Kevin

[Steve]

THe expansion tank must be the uppermost part of the system, or the free air will end up in the top of the rad, or the top of the inlet manifold - either way overheating is a possible result.

Sounds like you need to rectify this just a case of moving the header tank


Steve
GD/LS1/T56 in progress
sgullick@waverider.co.uk

[kdavies3]

Make sure the thermostat is opening fully. Better still remove altogether to try it.
Is this a new build or just a new problem thats just appeared?
Maybe the radiator isn't big enough.
By the way Steve is correct about the header tank.

http://animatedgif.net/flags/-flags-uncat/Wales.gif

Kev Davies
Dax, 383ci Chevy Stroker, Tremec TKO
South Wales

[NC427]

Hi Kevin,

what you wrote sounds pretty familiar to the problem I was confronted with when I sorted the cooling issues on my DAX (no supertube) 6,4ltr CSB stroker.

Guess you are correct upon concluding that the bottle neck is the expansion tank being fitted lower than the top hose/inlet manifold.

Will try to attach two pictures to this mail.

What you could also check / do:

1) High flow water pump

2) Check if the radiator is fully working or if part of the
system is blocked.

3) When I bought my Dax the fans where installed in front of the
radiator which resulted in bad cooling. Installed them behind the
radiator which helped a bit.
Finally got installed a single high perfomance radiator which
resulted in a mayor improvement re colling system temp as well
as it imporved the oil-temp as I installed a drysump system
and the external oil tank is no cooled by the airflow of the
radiator fan too. fan is controlled via thermo-switch.

4) Radiator unit: Last but not least installing an aluminium raditor
unit helped to finally getting fully controlled cooling system
temperatures.

5) Thermostat: Points of view may vary but I would not run the engine
without a thermo unit. Had mine reinstalled and with the above
changes there is no problem at all. Even this summer with 33°C
outside and being trapped for more than one hour in traffic jam
with stop and go driving there was absolutely NO problem with
the water temp.

Good luck
Carsten

[SimonP]

Those thermostat housings which have the hose connection pointing up at 45 degrees are the main cause of these situations.
The pump can *circulate* coolant adequately at idle (ie when the complete circuit is full of coolant!), but it does not have the power to generate a head of pressure to "push the coolant over the hill" caused by the high point in the top hose. Therefore no circulation = no cooling = overheating.
If you felt the radiator in this situation, it would likely be barely warm if the fan was running

Use a 'stat housing that has the hose connection exiting horizontally if your engine ancillaries allow this.
You will then have much more "margin" to work with when siting your header/expansion tank.
Maybe you will not even need to relocate your expansion tank from its current location.


Simon.

[SimonP]

Here's a photo of mine on the GD.
http://www.cobraclub.com/crcforum/user_files/2491.jpg

Yes, there's still a little "hill" for the coolant to overcome, but it is very slight, and the system works well.

I've since seen some GDs with the header tank bolted below the crossbar to enable the top hose to sit horizontally.

Simon.

[Kevin Smith]

Many thanks for all the help.

Regards
Kevin

[graham]

Yep I installed a 90 deg right angle outlet which can also be turned to what ever angle you want ie pointing forward or forward and to right a bit. Expensive and had to be imported. AK header tank about same level as outlet and no probs. Also I only have a smidgeon of water in the bottom of the header tank as expansion of the water when hot can easily use up the spare volume. also one small hole drilled in stat seems to aid any bleeding of air. Runs at 78 to 82 degrees before fans. If guage is accurate!

Graham