Something odd about this Abarth engine

[mirafiori76]

I noticed something odd about this Abarth engine. Is it me, or does it have 2 !! thermostats? There's nothing much to learn for me concerning group 4 131 Abarth cars, but i've never seen this before.
Anybody out there to shine a light on this?

[N. Dinis]

I would say that the upper part is not a thermostat but a simple T. Our engines have it metal shaped right after the cambelt, but in there for some reason there's a hose putting it further near to the radiator... Just my 2 pennys

[Thotos]

The upper part certainly looks like a thermostat but can't really see the lower one. So I'd guess that the lower one is a simple T-piece. Hot water rises so with the thermostat higher up it will open slightly earlier and therefore keep the engine slightly cooler.

In my 8 valve engine, the blender thermostat has been removed, the T-piece in front of the head has been replaced with a simple 90 degree elbow for the top hose to the radiator and the thermostat (from a Ford Fiesta!) is fitted in the head (just like in a 124 twin cam). Controlling the temperature with a thermostat in or near the top hose is better and I think that's what the top thermostat in the pictured Abarth engine is doing.

[mirafiori76]

Right what i was thinking. Looking at this engine i'm sure it's a "winter" version. There's no airfilter.

[Tas131]

the thermostat is fitted in the head (just like in a 124 twin cam). Controlling the temperature with a thermostat in or near the top hose is better and I think that's what the top thermostat in the pictured Abarth engine is doing.

If the thermostat in the head was better, Fiat would not have changed to an external one. The external thermostat allows continuous full coolant flow through the engine, the in head type doesn't allow flow until it opens.

[Thotos]

If the thermostat in the head was better, Fiat would not have changed to an external one. The external thermostat allows continuous full coolant flow through the engine, the in head type doesn't allow flow until it opens.

The in-head thermostat allows some flow as it has a small hole in the diaphragm. But I agree that the external blender thermostat allows more flow within the engine while closed so will give more uniform warm-up and will also make the heater work faster during warm-up. Good reasons for Fiat to change to this type from the in-head thermostat. But I believe that once the engine is up to temperature with thermostat open, there's better temperature control from a thermostat 'sensing' the temperature within the head than an external thermostat mounted away from the engine within the pipework.

[mirafiori76]

I would say that the upper part is not a thermostat but a simple T.

No, the upper part surely is a thermostat. This is an original fitted to all Abarth 131 engins.
The lower one i'm not sure of. It's not clearly visable if this is just a T-fitting.