RE: Air pumps, tattoos & rear engined cars

["Brian Shorey" <bshorey@domain.elided>]

> From what I understand about the older style of cat, they require the
excess
> air factor (lambda) to be greater than 1 (lean) to work effectively, thus
> introducing the wonderful air pump to add more air to the exhaust stream.
> This makes ( and I may of course be wrong ) the air pump superfluous when
> there's no cat installed. Perhaps Alfa didn't want to change the engine
> setup between California / noncali cars ?

'75 Alfas w/Spica FI (non California cars, I don't think Alfas sold in CA in
'75) came equipped with air pumps and no cats.  The air pump was good enough
to meet emissions in 49 states, but not good enough to meet CA emissions.
The cat was added in '77, I think, which is when Alfas started selling in CA
again (I think).

My '74 Maser, w/Webers, also has (had) an air pump with no cat.

Fwiw,

bs

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