1966 199/232 Air Guard

AIR cars got different carburetors and distributors as well. The AIR system itself doesn't affect how the engine runs, but the tune-up specs that went with it did.

all that stuff works fine when dialed in right, but in nerd-speak they are all "brittle" -- meaning, they don't have much range/tolerance for things being out of whack. when totally spot-on, it's fine. the wrong thing out of spec/not set/etc and the engine runs like crap. i got my 1975 Gremlin 304v8 to run perfectly with all of the smog junk set up, but man was it a PITA to get right.

the modern "closed loop" stuff is vastly superior, but that's changing the subject. the A.I.R. just squirt air into the exhaust port, zero impact on performance except for the gulping pump which probably consumed one or two HP. it just uses waste heat to burn off HC's that escape the combustion chamber. it's all unsightly under the hood but otherwise no big deal.

i think the worst thing in those early years was the crap spark timing, and TCS that killed advance (especially when it's controls go crazy). fix that, and A.I.R. working right will give you bragging rights in 2014 :-)

The hardest thing with smog engines is when people remove or bypass all of it thinking they know better and you try and restore it all back to stock.

That's no fun.

uncljohn wrote: 'Specially when you take into consideration the number of components that are just flat not manufactured any more any where!

...and the things that had several different versions/calibrations within a single year and changed every year. One engine could have 4 different carburetors, 3 different EGR valves, 2 different CTO's....and all are only identified from each other by the part number, which by the way, are not made any more and the few that are made are "universal fit" ones hat don't work properly in any application.