73 smog pump question
Thread Starter
Pro
Joined: Oct 2006
Posts: 524
Likes: 8
From: Manahawkin NJ
73 smog pump question
I am in the process of putting the smog pump back on my 73 corvette. My problem is that the 2 way nipple is missing of the back of the diverter valve. I looked up pricing on a new diverter valve and almost fell out of my seat. Any suggestions as to where to find one would be greatly appreciated. I am ready to put this thing back in the box and back into the attic for another 30 years.
thanks
thanks
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
You can assemble all of the smog stuff on the car [so that it 'appears' to be stock], but does it have to function? If the smog pump is turning, who cares if the system is pumping...or if the pump input is blocked off and the output is dead-headed?
Racer
Joined: Sep 2008
Posts: 403
Likes: 7
From: Space Coast Florida
Since this thread is about smog pumps, can someone tell me how they work? I know it was the precursor to the cat converter but all I know is that there's a vacuum line going to a tin box under the hood..
Racer
Joined: Nov 2008
Posts: 364
Likes: 0
From: Anaheim California
The smog pump was an air conpressor that injected air into the exhaust manifold to provide for futher conbustion to burn off the unburned gas from the cylinder ignition. The vaccum hose controled the dirverter valve to prevent the air injection upon decelleration to prevent backfire. This is my take on it but others may know more.
Thread Starter
Pro
Joined: Oct 2006
Posts: 524
Likes: 8
From: Manahawkin NJ
Function was next question. My thought was to possibly remove the belt and only put it in place when I am showing the car. Would I still need to block the lines on the smog tubes that come off the manifolds, or would the check valves on the tubes do that already. The pump does seem to work properly, just that 2way nipple is missing. I don't really care if it functions, just going for that 100% correct look.
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Safety Car
Joined: May 2006
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From: Shelton, Connecticut
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
Try some of the older junkyards that they would let you walk around in.
I found a complete Smog system on a 72 Chev Impala in a yard in Mass. in the late 80s.
It worked for my 72 LT-1 a/c coupe. Ask any old time drag racers in your neighborhood. Usually, the first thing that disappeared on a new car was the smog equipment way back when. Some of it is still in basements and garages.
If you don't use the pump, the tubes will clog up fairly quickly with combustion byproducts. I wouldn't put the tubes on unless the pump was operational.
Good luck.
I found a complete Smog system on a 72 Chev Impala in a yard in Mass. in the late 80s.
It worked for my 72 LT-1 a/c coupe. Ask any old time drag racers in your neighborhood. Usually, the first thing that disappeared on a new car was the smog equipment way back when. Some of it is still in basements and garages.
If you don't use the pump, the tubes will clog up fairly quickly with combustion byproducts. I wouldn't put the tubes on unless the pump was operational.
Good luck.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
You could seal off the tubes before you install them. That way they won't clog up. Keeping the belt on the pulley is not a problem, as long as you block off the air input to the pump. That way, there isn't anything to pump and the pump won't really be doing any work. You may still want to provide a small exhaust path from the pump, just to make sure there won't be any problem.