Hello again,I am after some advise regarding the cooling system on a A112 engine fitted in a 600d. I have mounted the radiator on the front of the car also I have kept the radiator at the back with a electric pacet fan.My first question is: Can I install a thermostat , if so how ?. My second question is: I have fitted a fiat uno water pump which has two outlets ,the main one is the return but the one on top I am not sure where to send this.Can I connect it to the cylinderhead ?.I have not fitted a expansion tank. Thanking you for any help.Regards
I had that problem too. What I did was to install an electric fan with reversed air flow driven by a thermostat installed in the bottom of the rariator. In order to install that thermostat, just take of your radiator and take it to a radiator repair shop (that was what I did).
The water pump you used has 2 outlets. The first is foar the engine radiator and the second (the small one) is for the heater radiator. A112, 127 and Uno 45 had heater radiators. The 600 doesn't have one, so you just connect it to the engine head.
Thank you Chris for your advise.I had the radiator modified so the outlet at the bottom points to the front of the car ,I will look into fitting a thermostat in the radiator.Many thaks
Hello Kammtail
1. You MUST run a thermostat or as a replacement a 'banking sleeve', with a 3-5 5mm holes. Here are the reasons. The waterpump must have something to pump against. When this happens, the pressure inside the block is higher than the pressure in the general cooling system, and this lowers the boiling temperature. The thermostat or blanking sleeve also slows the water down so that it spends sufficient time in the radiator to shed its heat. If not, then the hot water rushes back into the motor.
2. The top tank of the radiator must be higher than the top of the head. If not, then you must add a header tank that is higher. The water flow is as follows.
A - From pump into block
B - through block and out of the head to thermostat.
C- From thermostat to the header tank (or top tank of radiator)
D - From bottom of radiator (rear radiator) to top of front radiator.
E - From bottom of front radiator to input of waterpump.
3. The front radiator should have a 'bleed valve' on the top of the radiator to bleed out any trapped air. Better yet, run a small copper line from the top of the front radiator to the top tank or rear radiator (or header tank). This forms a balance circuit and automatically bleeds out any air that may be trapped in the front radiator.
4. NEVER run more than 30-40% antifreeze (coolant). Remember that the best medium for transferring heat is PURE WATER. However it boils at 212 degrees (100C). Coolant (ethelyne glycol) is the worst conductor of heat, but it does not boil very easily as it is alcohol. So a mixture of water and alcohol is a good compromise for a street car. For a race car use plain water with Water Wetter added. This aids in heat transfer by reducing surface tension of the water.
5. Use a higher pressure radiator cap. 14-18 lbs id good for the street, 18-25 for competition. This is the most often overlooked cooling part. If the cap is more than 4-5 years old get a new one.
This is my recipe for success. I am sure that there are other ideas, but I have found this to work even with motors putting out well over 100 HP on 38 C degree days.
Regards,
Paul
www.scuderiatopolino.com
USA
Hi Paul, can you say which electric fan fits/works well on the front side of a stock 600 radiator? I am planiing on using an X1/9 thermstat and hub mounted on the 600 radiator to control the fan.
Thanks,
Gil
Gil
I have heard that the Fiat 128 electric fan works OK. Likewise you could look at a company like Davies Craig. They make aftermarket fans that come in various sizes.
Regards,
Paul
www.scuderiatopolino.com
USA
Hello,
Paul why the higher pressure radiator cap is better? it wont make the "fresh" water from the extra tank flow to the radiator too late to help colling?
Using water on the cooling sistem wont make the sistem have rust earlier?
Have you ever tryed to use a mechanical water pump together with a mechanical fan? This will make continous air flow in the radiator.. isn't that a good thing? In spain and serbia theres people with 903cc engines and fiat 600 stock water pump without cooling problems and in serbia they only use the pump from fiat 900 van even on 1050 70HP cars without extra radiators and no problem (and with stock air flow).
Thanks for all the knowledge you share with us.
Alapimba,
The water in the "tank" is not any fresher than the rest of the system. All of the water recirculates through the entire system, whether it has one, two or twenty radiators.
If rust is a real problem, then you can add some rust inhibitor. However the items used in a water cooling system are generally made of materials that stand up to water very well (aluminum, copper, cast iron), particularly if the system is sealed and oxygen is generall excluded from the system.
The reason to increase the release pressure of the cap is to increase the overall pressure that the radiator system can hold. This will raise the boiling point of the cooling water. In may race car I use pure water, with a water surface tension release agent (no alcohol as the rules do not permit it). I use a 24 lb cap and even at 220 degrees F (104 C) I do not lose water.
I am quite confident that if the water system is properly plumbed, can hold pressure of at least 15 PSI that the standard Fiat water pump is quite capable of circulating the water in the system.
A electric fan has the benefit that it can move the same amount of air whether you are moving or standing still. This makes the assumption that it has a good shroud around it that is properly sealed against the radiator core, the core is clean and air can be pushed/sucked through it.
Doing analysis of cooling systems by remote control is always a problem. All I can do is tell you the physics that come into play in ANY cooling system.
Regards,
Paul
Hello
Yeah i know it's hard to analyse anything so far way i just asked this things so i could understand the theory :)
The water on that extra tank that came as stock on any FIAT 600 isn't to when the cap of the radiator open "fresh" water come in?
Didn't knew that with more pressure on the system the boiling point was higher, but with more pressure and more hot water isn't more dangerous for the head gasket or something like that?
The electric fans that you install in your cars are allways working or only when the system reachs some temperature?
Thanks
Roger
Roger,
Just because the system will allow higher temperatures, does not mean that you HAVE to use this extra margin. Frankly, I run my race car wtih 13.8:1 compression in the middle of summer with ONLY the front radiator and the water temperature NEVER goes over 190 F (88 C). I use an electric water pump and NO fans of any kind. BTW - I have only lost a head gasket ONCE, and that was when I had a broken radiator hose and lost all the water.
Of course for road use, with traffic, you must use a fan. I would set it up so that the fan comes on at around 180-190 F (82-88 C).
Regards,
Paul
www.scuderiatopolino.com
Hello Paul,
And Thank you for your information regarding the cooling problem on my A112 engine I will take your advice.
Just on question where do I install a thermostat as I dont appear to have a housing for the stat ?.Or where abouts would I install a blanking sleeve .
Many thanks
Greg
The thermostat is installed in the head outlet. You can use one from Fiat 850 and block the output of the cabin heater or if you can find one from a Zastava 750?!!!
Hope I helped.
Chris
Hello Kammtail
Yes, use the 850 housing that will work fine, but DO use a thermostat, as it is an integral part of the system.
Regards,
Paul Vanderheijden
www.scuderiatopolino.com