Air Pump

[morfirst]

Has anyone ever tried to do away with the air pump, check valve, control valve, A-B valve and servo diaphragm in relation to the exhaust system? As I see it these components allow fresh air to be dumped into the exhaust manifold to burn the exhaust gas.

[2ManyZs]

I don't know what your laws are concerning removing smog equipment on older model cars, but if you can do it by all means start taking it off.

That is usually one of the first things that gets done to a Z, just take it off and take out the nipples for the hoses and get an assortment of NPT pipe plugs and plug them up. Not only will this gain you an easy 5hp or maybe a slight bit more, it will make your car a whole lot easier to tune correctly.

There should be more than one thread under engine systems that will tell you anything you need to know about de-smogging your Z. Have fun!

[EScanlon]

As long as your car won't require emissions testing you should be able to without a problem. My 71 240 had any and all of the emissions stuff removed, and it has definitely cleaned up the engine compartment.

Thankfully in Washington State, cars from 1971 are not required to undergo the bi-annual smog check.

[kmack]

Like 2ManyZ's said, start taking it off. I went so far as to even cap off the EGR valve also, but at the time I had a '73 motor and the EGR was shot anyway. Now I have an early model balance tube that doesn't require the EGR.

Taking the air pump and it's various plumbing off will not be all that difficult. The hardest part will be removing the air injection tubes from the exhaust manifold. I pulled my manifold off the car, cut the tubes as close to the manifold as I could, then drilled the rest out. Later I tapped the holes for a 3/8" NPT flush pipe plug. Now you have to really look to see where the tubes went in. (Or you could always just get a header and not worry about it.)

The rest of the job is just plugging up the various lines. Good luck.

[2ManyZs]

I guess it should be said that if you are going have problems pulling the plugs on the exhaust manifold you will probably end up pulling the carbs and intake to get to those stubborn plugs. As long as you go that far it probably be better to go ahead and get a header without the smog fittings. If you take it apart that far why not get rid of a bunch of "dead weight". Between pulling the air pump and stock exhaust manifold you will probably get rid of about 10 pounds or so, maybe a bit more. There are headers that you can use to connect to the stock exhaust if you choose to leave that as it is for now.