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Here's a pic of my current engine bay. All the pollution stuff was removed and the air cleaner is an aftermarket unit. Current carb is a Holley and I just had a quadrajet rebuilt to install. Questions are as follows: 1. I have both and original air cleaner and the one pictured. IF I leave the air cleaner as pictured, the breather coming off that valve cover would have to be plugged (or so I assume)? 2. IF I switch back to the original air cleaner I do have the little connecting tube from the valve cover breather to the air cleaner. BUT you can kind of see down by the exhaust manifold, there's no heat riser cover down in there to connect that 2" heat riser tubing to the air cleaner intake ( on the original air cleaner). With all the pollution stuff gone, is there much of a need to replace that heat riser cover to connect to the air cleaner! I understand if I go this route I also have to connect one vacuum line to the air cleaner hockey puck(I think that's what they call it). Thanks
Those aftermarket chrome air cleaners use to include a fitting that bolted onto the air cleaner base. You then ran a hose from the fitting to a breather.
Remove the chrome sir cleaner, look for a dimpled outline where the fitting would have bolted on.
Technically, you could run the engine as is. There is a filter in push in housing. Since it would be breathing filtered air from the air cleaner, it might need more frequent service and replacement
Ok, there's at least three systems you are combining in your thoughts. Not all of them are "pollution stuff."
1. Exhaust gas re-circulation. EGR. That's that blockoff plate on the intake manifold, and there was a vacuum motor to let some exhaust gas into the carb to lean it out some on cruise. That was pollution, and a little economy based. It looks gone, it can stay gone.
2. Warm air warm up, I forget what it is actually called, it debuted as Climactic Combustion Control in 67. That exhaust manifold 2 inch pipe does go to a wrapper around the exhaust manifold. If it's not there, and you are happy with how it warms up, then you don't need it, and you also do not have to hook a vacuum line to the thermac motor "hockey puck" on the air cleaner as no vacuum = open, which is what you want.
3. Lastly, the Positive Crankcase Ventilation PCV. You do need this. It's for engine health. I believe that valve cover port goes up to the air cleaner, and there's a little foam spark arrestor it clips onto for the air inlet. It sucks from the air cleaner, down into the valve cover, across the engine, up the other valve cover, and into manifold vacuum on the intake somewhere. This sucks out and burns blow by fumes, and this is necessary.
Thanks for the reply. This all makes sense. I'll put the original air cleaner back on, but skip that 2" hose that ran from the manifold up to the hockey puck on the air cleaner. I like the look of the original air cleaner better anyway. Then that takes care of the that exhaust manifold shroud and the 2" hose.
I've attached the pics of my original air cleaner. The first pic is that pipe from the valve cover on the left side. The 2nd pic is of a line that comes from the right side valve cover and goes into what I assume is a vacuum port on the carburetor which is a fairly large vacuum hose compared to some of the others.
I don't understand the "filter" you mention. Unless it's a built in filter on the right side valve cover deal that the short metal pipe connects into. ? I've not changed that out but assume that is just press fit into the valve cover with a rubber grommet of sorts and it can be replaced??
The thing that is now hooked up is the PCV inlet, it has a little filter that goes roughly where the green outline is. That is air inlet for PCV.
Check the vacuum line here in red, hopefully the other end is not connected to the engine.
Filter looks like such
This line in yellow is the PCV outflow and gets sucked into either the intake or the base of the carb, which is manifold vacuum. It is, indeed, a large line and should be like the vacuum brakes line.
That line in "yellow" goes directly to the carburetor, no other connections or "T's" along that line.
That Filter I do not have, that pipe comes up from the valve cover gasket and just goes to a rubber grommet on the side of the air cleaner. I'll see if I can get a filter at NAPA .
That "red" circle shown is a vacuum line and appears to feed back to the carb. I am now suspecting I should plug that line! as it would be an open vacuum line that is not good.
Update: That red circled small vacuum line goes to a little unit mounted inside the air cleaner toward the rear of it.. Have not idea what that little thing does but it does NOT run to the carburator.
That line in "yellow" goes directly to the carburetor, no other connections or "T's" along that line.
That Filter I do not have, that pipe comes up from the valve cover gasket and just goes to a rubber grommet on the side of the air cleaner. I'll see if I can get a filter at NAPA .
That "red" circle shown is a vacuum line and appears to feed back to the carb. I am now suspecting I should plug that line! as it would be an open vacuum line that is not good.
Originally Posted by radiofellow50
Update: That red circled small vacuum line goes to a little unit mounted inside the air cleaner toward the rear of it.. Have not idea what that little thing does but it does NOT run to the carburator.
Ok good the yellow marked line goes where it should.
The filter is not vital, get one soon but it is not a show stopper. Also available at Rock Auto and such.
Ok, here is how the thermac air door works, the hockey puck on the air cleaner. If you were going to hook this up, which you are not, the way it would work is: Vacuum line from thermac, to the little unit (which is a heat activated valve) and then to manifold vacuum. When the thermac sees vacuum, it closes, and routes the air intake up that 2 inch pipe that went to the exhaust manifold shroud. If the engine is off, the thermac opens the chimney on the air cleaner directly. Once that little heat valve heats up (it has a bimetallic thing inside it), it cuts the vacuum off to the thermac. Thus, the thermac opens the chimney until the car cools down after driving.
Since you are leaving it all disconnected, the thermac is open all the time, and that hose does nothing and can be removed for cleanliness.
One last question. The rubber grommet that is in the vertical side of the air cleaner does not look like it will fit that little crankcase breather filter! Do I have the wrong grommet? I don't seem to find just a 90 degree grommet that will accept the breather tube coming off the valve cover! Pic attached of the grommet I have.
They may have not had a filter that year. You certainly don't need it short term, clean out your air cleaner while you have it off, and it will be fine for at least the short term.
