Cooling issues

[Vigri]

I would like to warm up an old topic of mine. As already written before I have a Maserati 222SR (year of production: 1991) and I have not managed to resolve this cooling problem with 4 years.

At the moment I could get maximum 2 fast laps on the track and then the car overheat (temp rises to 120C and this is accurate as I have installed separate water temp sensor and gauge) and starts to push coolant out through over pressure valve on coolant expansion tank.

During that time I have done following modifications (in more or less chronologic order):
• Changed radiator to new one (custom made aluminum one)
• Changed thermostat for new one
• Installed electrical water pump with controller (Davies Craig EWP115)
• Removed thermostat completely (later installed it back as it made no difference)’
• Changed cylinder head casket
• Changed coolant expansion tank cap (old one did not hold pressure anymore)
• Removed AC radiator for better air flow
• Tried running without a hood for better cooling (a bit better but, no significant effect)
• Defected whole cooling system (one small leak was found)
• Installed new fuel pressure regulator to increase fuel pressure and make car run a bit richer on higher revs
These are more or less all the modifications that I have done to resolve his cooling problem and nothing has had significant effect.
I have also made small modification to improve car performance but this should not cause this overheating problems:
• Catalyst converter is changed for “racing” one
• Original boost controller is replace with adjustable one but turbo pressure will not exceed 1,0 bar
• Original air filter changed for two cone air filters
• Blow of valves added

Does anyone have any idea what to try next or has anyone had similar problems whit their car? I’m running out of ideas here…

[Muc3200GT]

Hi Vigri

When reading the thread a lot of things have been discussued, but two things came to my mind:

- what kind of cooling liquid you are using ?
- wheter this is normal operation that the radiator only cools down by 4 degress....as described in your last post in 2010
(although I have no idea what is the expected value , it depends also on the flow of the liquid wheter this is a good or bad cooling performance)

regards

Jörg

[merak66]

Hi Vigri,
as you wirte, that you have the problem already after 2 laps, i don´t thin the reason ist the Kind of liquid you use. And i understand, that you´r running out of ideas.
I know that there was a race series with gihiblis in the past. May be you should find someone who took part and talk to these people how or in what Kind the changed their colling System in the cars they used

[merak66]

sorry for all the mistakes, to fast on the button.... shit autokorrektur
Micha

[Muc3200GT]

yes, maybe there is nothing wrong with the kind of liquid used for normal use but as we discussed already there is a differnce wheter its pure water, 50:50 glycol  or 100% glycol, and also waterwetter claims better transition of the temperature to the metal. And track racing is of cause different to constantly 200km speed on "autobahn" where one has 200km airflow, while on track one has typically full throttle with much lower air speed where it could be a probelm to compensate this with the fans. (maybe they are not turning with full speed as contacts as corroded a bit).

So I dont claim this is the exact cause but those are just things which could influence or improve cooling performance.

[gemballamechanico]

i think that the waterpump doenst work corectly..i read that you installed also an electric waterpump but i think that the problem is your original pump..you have changed everything an modified many things but not the waterpump.how can a ghibli cup with much more horsepower get 10 rounds on race track without any problems..

[Muc3200GT]

what is/was the absolute  temperature on the inlet/ outlet of the radiator when you did the mesurement?

if inlet was 120 and outlet 116, then I could imagine more waterflow would cool more, if it was 90 and 86 when water temperature was 120 than probbaly too few water enters the radiator.

[Vigri]

I’m using regular green antifreeze that you could buy from any gas station. It might be worth trying also other liquids but I doubt if it will resolve the problem entirely. I don’t have possibility to try this out this year any more but I will keep this in mind next year.

Original water pump does not work at all anymore because in order not to have it interfere with electrical water pump we had to remove impeller from original one. I’m now using Davies Craig EWP115 (http://www.daviescraig.com.au/Electric_W...tails.aspx ). It has flow rate of 115L/min but I don’t know if this is big or small number but in regular driving it has no problems cooling down the engine even if it is set to cool it down to 75 degrees.

Regarding the measured temperature difference between inlet/outlet, this was done in the parking lot with IR thermometer so this might have significant measuring error. Engine temp was then ~90 or less. This was also measured before I changed to electrical water pump if I remember correctly.

[Muc3200GT]

I’m using regular green antifreeze that you could buy from any gas station.

you are using a 50:50 mixture of antifreeze and water I suppose ?

[Vigri]

I don’t know exactly what the mixture is as I have bought already premixed coolant but I would assume it is 50:50.
I also posted this problem to Maserati Biturbo Zentrum forum and there general idea seems to be that it is head gasket failure.
http://groups.yahoo.com/neo/groups/Bitur...pics/34390