Technical What’s this

[Kiltedboarder]

Hi everyone
Just looking round the engine and no idea what this is. Anyone shed some light on it

Thanks

 

[the hobbler]

Hi everyone
Just looking round the engine and no idea what this is. Anyone shed some light on it

Thanks

It looks as if something may have fallen off the thermostat flap. I know that it will be a bit of a 'faff', but it might be wise to take out the distributor (mark where it fits in relation to the crankcase, and note where the rotor-arm is pointing first) and then remove the thermostat-housing.

 

[Kiltedboarder]

Sorry mate, nothing is broken. I just wondered what it was and as you point out it’s the thermostat flap. How does it work and what’s is real function

Thanks

 

[fiat500]

Sorry mate, nothing is broken. I just wondered what it was and as you point out it’s the thermostat flap. How does it work and what’s is real function

Thanks

The flap has a strong spring that is always trying to force it open. But a metal, bellows thermostat is connected in a between the flap and the cowl and keeps it shut. The thermostat is in the hot flow of air being pushed over the engine. There is liquid alcohol sealed inside the thermostat; (in some versions it is wax). The heat gradually vaporises the volatile substance and increases its volume, and in doing so the thermostat is elongated and unable to overcome the force of the spring. That allows the flap to open and the hot air to exit. This action is reversed as the engine gets cooler, and the flap can operate partially open or sometimes shut.

It is a way to allow the engine to operate at an optimum temperature, particularly when warming up or in cold climates.

 

[Kiltedboarder]

Awesome, really good write up and info. Thanks for that - much appreciated