Alfetta CAT

[JMNegrin@domain.elided]

Stefano in Oakland asked a couple of question in re catalytic converters:

<<What affect does the air injection pump on 79 Spica cars have in terms of
power? With/Without?>>

  The pump doesn't draw that much.  I would guess less than 1 hp.  Consider
that a starter motor puts out that much to turn the beast over when starting.
I had my air pump seize and break the belt.  I never new it happened, until I
saw the belt lying on the front body work, when I was cleaning up the motor
compartment.

<<What affect does it have on catalytic converters?  With/Without?>>

  It provides extra oxygen/air to the cat, so it the unburned hydrocarbons
will have something to react with when the catalytic converter starts
catalyzing after it gets hot enough to "light off" the process.

<<The belt on mine seems to have been left off or fallen off about the time I
had the Shankle headers put on. The headers have the fittings and they are all
connected. I of course have more power with the headers but don't know what it
would be like if I put a belt on the pump. I also put on a brand new cat and
am wondering about the temperature and/or gas makeup going into the cat.>>

  I ran without the air pump/smog pump for several months.  I think the worst
things that would happen is that you wouldn't pass a smog test, and then get
branded a gross polluter, with all the beaurocratic static that entails.  Your
catalytic converter might not get enough extra oxygen to work well enough.
Too many unburned HCs out the tail pipe as a result.

  Alfetta cat system is rather simple/crude.  Run the system a bit on the rich
side, to minimize oxides on nitrogen.  Let an oxidizing catalytic converter
take care of any unburned hydrocarbons.  Only problem is that if it runs too
rich, the cat does too much work and then it WILL overheat.  IF the thermal
sensor is still installed (is that the long skinny temp sensor-looking probe
you were asking about?) the "Slow Down" light on the dash lights up.  Who said
that engineers don't have a sense of humor?!
SMFT

Jay Negrin
76 Alfetta GT (CAt w/ no temp probe, and a working smog pump, again)
ARO Southern California

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