Summer/Winter thermostatic capsule airbox

[Modano]

Hi
as many of you (I guess), my Coupé is fitted with a thermostatic capsule that is supposed to let exhaust gases back in the airbox. I suppose this is replacing the fixed Summer/Winter position of earlier boxes and is supposed to bring a proper amount of exhaust gases depending of the outside temp.
And, as many of you (again, I guess), this capsule is totally out of order (in my case the rod is difficult to move by hand, so I think the capsule, even if it was properly calibrated and ok, wouldn't be able to move the flap).

I have two questions :
- How critical is it ? At worst it is receiving too much hot gases when it is hot outside and engine is hot, or, it is receiving none when air is cold. From what I read, this seems to be an important part of the fuel management, but I don't know how important it is (would it make a properly set up engine go rough ?)
- I see older airboxes from time to time. Is it possible to replace it or did they change the whole intake circuit ?

Thanks a lot

[peteracs]

Hi

The air box you are referring to has its cold air intake from the front left of the car. The older manual switch winter/summer air box takes the cold air from the front right of the car. I have the older style air box and I use the car in non icy temperatures, ie normally above 5 degrees and have no issues starting or running it by leaving it on the cold air intake all the time.

I think there were other styles of air box, an Australian one comes to mind. Not sure if that was manual or automatic.

Peter

[Nigel]

There was another that I recall, where the air filter
lid could be rotated between winter and summer.
It had a curved plate mounted vertically that would close off/open
the 2 intakes.

[peteracs]

Hi Nigel

That sounds like the one I refer to as being on the early cars. I think the Australian cars also had a different design, but I could be wrong….. poor memory that I have.

Peter

[squiglyzigly]

There was another that I recall, where the air filter
lid could be rotated between winter and summer.
It had a curved plate mounted vertically that would close off/open
the 2 intakes.

Yes this type is fitted on my series 2 Berlina and I have to say that running the car this winter with the airbox lid set to ‘I’ (inverno/winter) helps prevent the carb icing a little in the first mile or two from cold start.

Ian

[Modano]

Hi All
yes, the box you mention all has a "static" Winter/Summer position I/E in Italian, that is achieved through turning the lid.

This manual position of the lid was replaced by a capsule that in connected to the intake, and that is moving a flap to let more or less exhaust gases into the intake.

In my case, this capsule is broken, therefore there is no automatic exhaust gas intake control at all. I can move the flap manually and freely, but it will stay still.

My question was, how can this impact performance and operations of the engine globally ?
I mean, in my case I have only a few possibilities :
- Full exhaust gas opening, leading to always on hot gases in the intake (leading to carb vapor lock ?)
- No exhaust gas at all, leading to cold temperatures problems maybe ?
- Middle opening

And the bottom line is, maybe it would be better to change the system by an airbox of the earlier models, with rotating lid ?

[Neil-yaj396]

On my pre-facelift Coupe I always left the lid in the 'Summer' position. It did sometimes lead to a slow warm up.

I must check the capsule on my current car. After 40 plus years I imagine many of these don't work......