1973 Emissions questions

[Roman]

Ok guys, help solve a mystery for me...

Im trying to determine what emissions related equipment actually came on the 1973 340 e-bodies. 
Specifically, Im trying to determine if the air pump/ injection was standard on the 49 state models at that time.

What i do know is the that the evaporative system and egr systems were part of the game in 1973, and I have learned that there were no cats at that time either.
But how about the smog pump? 

( in a related topic, other Chrysler in 1973 still had the big blocks and I wonder if they too had a smog pump at that time?)

Very much appreciated any and all coments...

[Bullitt-]

My '73 340 did NOT have a pump or EGR.  Did have the charcoal canister & a few gizmos for emissions.   

[Roman]

Thanks Bullet thats great info...  No EGR eh? thats odd, i seem to keep getting conflicting info on the EGR for 1973.

[Roman]

So for a 1973 340 we have:

1) Charcoal can, and vacuum lines from tank .
2) PCV valve in the valve cover, plus lines to Charcoal can and air cleaner/ carb
3) ? anything else?

...........................
No cats
No smog pump
No EGR valve

[Bullitt-]

There is something in-line on the vacuum line running to the vacuum advance mounted on the firewall that senses air temp & disrupts the vacuum if the air is to cold.
Heat riser in the PS exhaust manifold.  Something down in the intake manifold that I never understood how it works.  Vacuum actuated doors on the air cleaner to divert heated air through the carburetor.   

[burdar]

340's also had a NOX valve on the firewall that was plumbed in between the carb and the distributor.  318 cars got an EGR and an extra vacuum control valve for the EGR.  The vacuum control valve was on the firewall right next to the NOX valve.  340 cars had a metal block-off plate covering the hole where the control valve was located.  Later on in 73, they stopped punching the hole in the firewall so no block-off plate was used.

It's possible that California 340 cars came with EGR.

[Roman]

Wow, great info guys!

[mopar jack]

The 73 340 manifold had floor jets under the the thermoquad carb that allowed exhaust gas to enter the intake and act as an egr. Car alwalys seemed to run better after they plugged with carbon.

[Roman]

Interesting..

The Nox valve helped to pull back the timing no? But it was never used on 340 cars?

[burdar]

340's DID use the NOX valve.

Feb built 73 340 car with NOX valve and no block-off plate next to it.


Oct built 73 340 car(HooD from this site) with NOX valve and block-off plate next to it.


Oct built 73 318 car with NOX valve and vacuum control valve.

[erat340]

Its called an Orifice Spark Advance Contol....OSAC...valve. It has a small orifice to delay vacuum to the dis. I believe 72 only cars had a temp sensetive contol next to it.

[Roman]

Alright..the court accepts the evidence presented ! lol.. Photographic proof... thanks.

So lets re: summarize then:

1973 E-Bodies 340 and 318 engines Emission components are :

1) Charcoal can, and vacuum lines from tank .
2) PCV valve in the valve cover, plus lines to Charcoal can and air cleaner/ carb
3) OSAC valve (firewall mounted and connected to the distributor vacuum advance)
4) EGR valve for 318 only
...........................
No cats
No smog pump

[erat340]

Yes, and as Mopar Jack says, 340 had always open floor jets which quickly plugged up(yea).