Osca - Fiat "E" & "I" Markings

[Keep it stiff]

This relates to my recently purchased 1963 Fiat 1,600s with the Osca twin cam.

I removed the air filter housing to get it powder coated. Air is routed via a what the manual describes as an "air silencer"

With the filter housing removed this revealed a detail that I had not noticed before. There is a second channel that finishes just a few mm from the exhaust manifold. The two channels are controlled by a adjustable flap allowing air to be routed either from the "air silencer" or from air drawn close to the manifold. The flap is linked to an external spring assisted lever with the positions are marked "E" and "I". The lever is not drilled for any cable connection. "E" I guessed might exhaust but in Italian would that be "S" for Scarico? "I", no idea. So I'm none the wiser on either really.

There is no mention in the manual of this adjustment, clearly it is intended to give the option of either drawing air at normal temperature or drawing air that has first been warmed by circulation around the manifold. The air filter housing is marked with a Fiat part number and the design of this flap & lever does not look like a later adaptation.

I would be interested to hear if this arrangement is duplicated in the layout of other cars and if so what the intention of a lever that needs to be manually changed to either setting.

[whiteonyx]

i would suspect that the adjustment is for warm or cold driving conditions.

[rallycross]

Summer winter not unusual on carburetor cars my old Ax Gt had the same thing.

[Keep it stiff]

In the "E" position it is taking air from the front of the car and in the "I" position air from around the manifold. That would add up with the Winter/Summer theory.

[bstark]

A.G. said:

Summer - Estate

Winter - Inverno

Wot 'e said

My old Renault 5 had the same setup (in French though, obviously)

[S0 What]

rallycross said:

Summer winter not unusual on carburetor cars my old Ax Gt had the same thing.

90% of carbed cars had it as well, later cars had a stat/vacum oppertaed one (wooo)