308 thermostat question

Could not be more important.

My suggestion would be to start getting your parts from a known good supplier. Superformance is not one.

 

For everything or for some things?

 

Ted Rutland once told me he refused to sell a thermostat that wasn't a "Ferrari part". I had to wait on a shipment from wherever he got them. He said other suppliers weren't worth the risk to the engine.

 

Ricambi America, T Rutlands and A&W are all vastly better sources.
And it is not just OEM vs Aftermarket. Sometimes it is but its about quality, correct parts vs going to Pep Boys.

 

I just replaced mine, that I purchased as an off-the-shelf replacement. I still have the old one that I can measure for you. In short, the bottom stopper should extend upon heating, whereas the large top opening opens up. This closes off the short circuit to the pump and opens the route to the radiator once the engine is up to op temperature.

https://www.birdman308.com/service/thermostat/thermostat.htm

You should check out Birdman's site for an excellent discussion on thermostats for the 308: there are some small but important details, including the exact outer diameter that can be important. I eventually found this model to be an exact replacement for the original, except for the little hole that I had to drill:
TH7020.82 Calorstat

Good luck,
Dario

 

That lower hole should be covered when the water is hot. I made an assumption that was understood. It will not cover the lower hole which is a bypass port until water is up to the opening temperature of the thermostat.

You'll have to excuse me but if that is not understood you should rethink repairing the cooling system of the car.

 

I would disagree with this based on my own (10+ years) experience and that of others that I know have been purchasing parts from them. In truth, there are not that many choices for our cars and I have found their parts to be generally quite good. There are as always some that come with "some adapting required" but overall the parts are good quality and fit correctly. Also, they sometimes offer (and clearly label) cheaper alternatives. When I have had issues, they were quick to reply and try to find a solution. While not always the cheapest, they are far from the top in terms of prices (at least, until brexit added systematic charges for customs paperwork...)

Just my 2 ¢

 

I knew that I had seen something on this before -- but couldn't recall where . Just ran across it again -- page C12 in the Mondial8/QV WSM:

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Nothing unusual with the pic ^ .
It’s cold so shrinks shorter and opens up the block “ short circuit “ That’s why it appears not to fit at the moment .

As the jacket temp rises ( see Steve Magussons post #11 ) it will lengthen from approx 32.5 mm to 44.5 , and close that bottom gap .Simultaneously opening a larger top gap sending more and more proportionally to the Fwds rad .

I replaced mine in the GT 4 followed Birdmans link above .Mine I thought was running slightly hot ( only in the summer ) .Gauge between 6 o clock vertical and say 1/2 way to 5 o clock - slightly to the right of vertical on steep hill climbs and waiting in summer traffic queues .

I did drill a slightly bigger hole than Birdmans example .This means more coolant escapes ( as well as burping air away ) Fwds to the rad when it’s cold and the upper channel is supposed to be closed .
it now takes a bit longer in winter to warm up and when warm , I mean really hot the gauge sits between 6 and 7 o’clock …..the left / cooler side of vertical.

With a GT4 you burp air out the radiator top screw with the car hot and parked up hill Fwds running .There is no air screw on the T stat housing .

Yes both fans work as they should ,Right with the AC switched on .In the winter it moves the needle to the left a little .The LHS fan kicks in if the car is sat idling on a summers day or hot after a spirited run out .

The reason why I changed it while changing the alternator ( sorry a U.K. super performance part ) Pulling the metal water pipe for better access .I noticed the horse show bit of metal from the T stat fast in the top of said pipe . Image Unavailable, Please Login Image Unavailable, Please Login
So with it bust it ran a bit hotter , not much past vertical.
Fortunately it ain’t big enough, either by accident or design to get through the metal pipe it lodges a few cm at the top .So when I pulled it and placed it on the ground ( car jacked up wheel well out working on the alternator) this bit fell out .

Suspect it s needed to get a proper closing of the lower or proper opening of the upper hole ?

Looking back in the history I note the T stat was replaced , appears on a invoice along with rewiring the fans with bigger seperate fuses back in 2015 .Unfortunately it’s didn’t say which part , no part reference .This was a very well know west London official authorised Ferrari repairer .
Anyhow it eventually broke ……but still kinda functioned , not catastrophic ……gauge eased to the right of vertical.