Desmogging the Z

[mbarjbar]

I'm new to the forum. I'd like to remove the air pump and injectors on my '70 Z.

Are there threaded plugs that will plug the holes in the exhaust header and what thread size? How about the vacuum canisters and lines attached to the intake manifold, can they go? I do not have to have the car inspected or smog checked.

Mike

[DeesZ]

There are a lot of good threads on this topic in the archives, you can find them with the search feature. Hopefully this link will take you to the most recent one... it may be of some help to you.

http://www.classiczcars.com/forums/showthread.php?t=32126

[TomoHawk]

Before you start removing things, you should define your goal for desmogging.

[mbarjbar]

Thanks, John. That thread helped alot. As far as defining my desmogging goals; I want to maintain the pcv valving, fuel evaporation system, but clean up the cluttered look of the engine. I want to eliminate the air pump and rails. How is driveability without the throttle closing delay system?

Mike

[Weasel73240Z]

I took off the air pump, and all the stuff on the balancing tube. When I first got the car running, I had on all the balancing tube stuff on, including the throttle delay. When I took it all off, I didn't notice any difference at all in how the car ran. I run new ZTherapy 3-screws. Heres a pic of the carbs/balancing tube with it all removed. I still need to permanently close off some holes on the balancing tube, it looks kinda hacked right now.

[Arne]

I agree, the rudimentary emissions systems on a 240Z (pre-73) have almost no effect on power or drivability at all, as long as they are maintained and in good operating condition. If more power or better drivability is the goal, might as well leave them alone.

[Sailor Bob]

I have most of that removed from mine and when I get home from this trip the smog pump is coming off as well. As to the air injector tubes on the manifold they are just too ugly - I am thinking a header is a good fix - at the very least they are coming off and being replaced with stubby bolts. I have no desire to maintain any of that gear.

I have driven mine as she is - works fine, other than the occasional backfire.

Edited October 10, 2008 by Sailor Bob

[Walter Moore]

When I found my car the air pump had already been removed. The rest of the smog controls were rusted up to the point where they had to be either removed or replaced. Since I don't think they actually accomplished anything, and there were no emission rules outside of California in 71 anyway....

But one note, if you remove the air pump there is an opening in the back side of the air cleaner that I assume was originally the clean air inlet for the pump. If you don't block that port, unfiltered air will bypass the filter element. It is a fairly large opening, around 18mm. I did manage to find an economical plug. In fact I had boxes full of them just laying around the house. (See picture below.)

But I strongly recommend that if you use this type of plug, CHOOSE ONE THAT ISN'T LOADED! :cheeky:

[DeesZ]

But I strongly recommend that if you use this type of plug, CHOOSE ONE THAT ISN'T LOADED! :cheeky:

Could make an interesting "booster", otherwise! Is that a 12GA? If so, I've got some 'full' brass ones around here somewhere if you want to dress it up.... they are really pretty when polished.....

[doradox]

When I found my car the air pump had already been removed. The rest of the smog controls were rusted up to the point where they had to be either removed or replaced. Since I don't think they actually accomplished anything, and there were no emission rules outside of California in 71 anyway....

But one note, if you remove the air pump there is an opening in the back side of the air cleaner that I assume was originally the clean air inlet for the pump. If you don't block that port, unfiltered air will bypass the filter element. It is a fairly large opening, around 18mm. I did manage to find an economical plug. In fact I had boxes full of them just laying around the house. (See picture below.)

But I strongly recommend that if you use this type of plug, CHOOSE ONE THAT ISN'T LOADED! :cheeky:

You got a CCW permit? I think you may be getting a visit from the BATF. :laugh:

[7277]

ditch it all...fuel rail and heat shield too! the only pricey thing are the coated MSA headers....

walter moore: love the shotgun shell !!!

Edited October 11, 2008 by 7277

[Weasel73240Z]

ditch it all...fuel rail and heat shield too! the only pricey thing are the coated MSA headers....

walter moore: love the shotgun shell !!!

I wanted to remove my heat shield because it just looks like s**t, but figured it might be a bad idea. I live in New England, so it doesn't get real hot here even in Summer. So can I ditch the shield with causing fuel problems? If it makes a difference, I don't run coolant through my SU's, I eliminated that system when I rebuilt, and I have a 6 - 2 header.