Making a '69 smog system non-functional

[Richard K.]

Does anyone know how to make a smog system non-functional, but in place on the motor just as original?
Do you just remove the smog pump's internal panes to disable the pump's air pumping power? Is there another method, or methods that can be used.
Thanks Much

[Joe L.]

Re: Making a '69 smog system non-functional

Does anyone know how to make a smog system non-functional, but in place on the motor just as original?
Do you just remove the smog pump's internal panes to disable the pump's air pumping power? Is there another method, or methods that can be used.
Thanks Much

Richard-------


Two things need to be done: first, remove the vanes from the pump. Second, check to insure that the check valves on the manifold trees are functional (i.e. only allow flow into the manifolds and NO FLOW upward). Better yet, plug the valves by inserting a metal disc of the appropriate size into the threaded end of the valve so that it seats between the top of the manifold tree threads and the seat of the valve.

By the way, I HIGHLY RECOMMEND NOT DISABLING THIS SYSTEM. Very little is gained by doing this. The notion that the system "uses too much horsepower" is absolute nonsense. Very little power is used. Second, the system helps reduce exhaust fumes which may otherwise waft into the cockpit, especially if the car is a convertible. I discovered this myself when my pump seized one day. It was much more uncomfortable and odorous in the cockpit until I replaced the pump (which didn't take me long to do). Lastly, it's a violation of federal law to tamper with this system and it may be a violation of your state law. In California, for example, while 1975 and older cars are exempt from biannual smog inspection, it's still illegal to tamper with smog systems originally installed on cars.

[Gary S.]

Re: Making a '69 smog system non-functional

I don't have the article but the gist of it was pretty simple. Iirc, John Hinckley wrote this but don't hold to that statement. I recall that the vanes had to come out and that is neutering or gutting the pump. Then one has to put a BB in the vacuum line going to the pump. The final part was to put a stainless steel flat head bolt, and I don't recall the size but it was small, in the line going to the "tree" to prevent back pressure from the exhaust coming up the line instead of pump pressure blowing air into the tree. The bolt is inserted threads first into the flared end of the pipe and the flat head of the bolt rests against the flare. When it is screwed down, it completes a seal.

[James G.]

Re: Making a '69 smog system non-functional

Richard-------


Two things need to be done: first, remove the vanes from the pump. Second, check to insure that the check valves on the manifold trees are functional (i.e. only allow flow into the manifolds and NO FLOW upward). Better yet, plug the valves by inserting a metal disc of the appropriate size into the threaded end of the valve so that it seats between the top of the manifold tree threads and the seat of the valve.

By the way, I HIGHLY RECOMMEND NOT DISABLING THIS SYSTEM. Very little is gained by doing this. The notion that the system "uses too much horsepower" is absolute nonsense. Very little power is used. Second, the system helps reduce exhaust fumes which may otherwise waft into the cockpit, especially if the car is a convertible. I discovered this myself when my pump seized one day. It was much more uncomfortable and odorous in the cockpit until I replaced the pump (which didn't take me long to do). Lastly, it's a violation of federal law to tamper with this system and it may be a violation of your state law. In California, for example, while 1975 and older cars are exempt from biannual smog inspection, it's still illegal to tamper with smog systems originally installed on cars.

I agree with Joe. The wife owned her California 77 since new. Still had every 2 year state inspection of parts and tailpipe emissions. The carbureator was a SMOG type and the car would not run right if modified. The car is now in Texas, with the grandson

[Mark G.]

Re: Making a '69 smog system non-functional

I found this procedure years ago and may help you.

1 - Remove the 4 bolts, and push the two retainer pins from the back cover.
you can use two 2x4's to sit the pump higher so as not to damage the fan on the front.

2 - Separate the back cover (fan guide) from the cylinder assembly.
You may have to use a few large screwdrivers and force the pieces apart.
After they are separated - you will see the fan blades inside the cylinder.

3 - Use a hammer and a large chisel to break apart the plastic and metal fan parts,
then they can be removed from inside the pump.
Make sure you get all the little pieces - there will be some pieces in the grooves of the cylinder wall.

4 - If the pump was spinning previously -
you can use this point to clean the aluminum housing and paint the rear cover Semi flat black.
water will not hurt anything - clean and detail everything.
If the pump was frozen - both of the bearings will need to be pressed out and replaced.

Don't use abrasives on the aluminum - I like to use soap and water, and then some aluminum cleaner.
Don't sandblast the pump, it will change the finish and feel of the aluminum.
The front cases were not painted - they are natural aluminum.

Clean and grease the rear bearing.
Assemble the pieces - bolt the bolts - push the pins back in place.

Install your white fan and you are good to go -

[Albert Y.]

Re: Making a '69 smog system non-functional

I once removed the belt driving the air pump and plugged the vacuum hose to the diverter valve just to see if there is any change in power. I noticed absolutely no difference in engine power or gas-mileage. The air pump has very low friction and can be easily rotated by hand; it does not consume much power. However, to my surprise, I did notice that the exhaust fumes out of the tailpipes had a gas smell. I think there are two reasons for that. 1) Obviously, leftover hydrocarbon is not burned in the exhaust. 2) There is an engineered vacuum leak from the diverter valve, through which additional air is supplied to the manifold. (A good and operational diverter valve does not hold vacuum.) The carburetor is calibrated to compensate for that. By removing the AIR system, the engine seems to run a bit too rich.