Anyone have a picture of a smog pump installed on a 1.8? Options

[DaveB]

Need help again. I found out my car was originally from California. Any indication of smog equipment is gone. So how is the smog pump mounted to front of the engine? I've seen the parts and would like to see an engine with this installed.

Thanks,

DaveB

[JeffBowlsby]

@Dave_Darling

Thanks Dave, great to hear from you, hope all is well.

My chart is based on some factory literature which organized it that way. The cat req. for 1975 1.8s is the last line of the chart.

PS, I may have misundertood your full comment. The factory called the heavy steel exhaust stubs (F-pipes) mounted to the heads on the 75-76 exhaust 'reactors' beacsue the heat they store helps burn off unburnt fuel as an emiision thing. Perhaps you wwere aware of that.

[DaveB]

I have a different question on the smog system. Why is the catalytic converter placed at the exhaust end between two mufflers? I am use to feeding the cats directly from the engine to get the necessary temperature for the reduction then heading into a resonator. I just don't understand why they didn't keep the earlier heat exchange design and feed into a cat then a resonator. Was it a space issue or is there a reason for this split muffler set-up?

DaveB

[wonkipop]

I have a different question on the smog system. Why is the catalytic converter placed at the exhaust end between two mufflers? I am use to feeding the cats directly from the engine to get the necessary temperature for the reduction then heading into a resonator. I just don't understand why they didn't keep the earlier heat exchange design and feed into a cat then a resonator. Was it a space issue or is there a reason for this split muffler set-up?

DaveB

space limitations? you really only have the space across the back behind the end of the gearbox and you don't want expense of two cats.

secondly i think it has to do with the mufflers on a 75 even though being separate still more or less imitating vw mufflers before cats.

in earlier mufflers even though the pipes come either end, usually one side has a feed pipe to a first chamber on either one end of the muffler or both feed to a central chamber and from there back into a chamber at one and and then through a pipe again through the central chamber to finally exit on the other side in the last chamber there. its a kind of side to side and back and forth labyrinth.

they just externalised that with the 75s into three components with the cat in the centre?

it fits nicely and cats run hot, was a position where it could be in airstream and radiat heat more harmlessly? it gets hot enough in the rear trunk with an ordinary muffler.

lastly - this is only a thought.
the originals were 2 way cats. they pulled the EGR off after the cat and from the final muffler. 2 way cats don't convert NOx. the NOx i guess got sent back through the engine and maybe that helped deal with it. someone with a bit more knowledge might know more. but they seemed to want to pull that EGR off the second muffler.