blocking off air rail ports

[ta240]

anyone know the what type and size fitting to use for blocking off the air rail ports on a 72 exhaust manifold?

[ta240]

Update, I picked up some 1/4" brass fittings. They start out a bit loose but as I tightened them in they seemed to block it off pretty well.

[JimmyZ]

Mine are blocked off. I have noticedd that they leak a little. This may cause some exhaust fumes to reach the cabin FWIW.

Someday I'll redo the plugs and get copper washers for a better seal. It is a funky metric thread if I remember right. Nothing in my bolt collection would match.

[obxtrainman]

I'm in the process of replacing my carbs with ztherapy carbs, balance tube, heat shield. I figure this is the oppertune time to get rid of that unsitely rail over top of all the new pretty stuff I'm going to put on.

I would think that the tubes leaving the rail connect to the manifold by means of inverted flare nuts. Therefore, I feel that the fittings are metric pipe size. I figure I have two options after the fittings are removed. A, Try to find metric pipe plugs. Or B, tap the holes to SAE pipe threads.

I soaked the fittings three times yesterday with blaster,,I'm going to hit them again tonight a few times. Meanwhile I'll search the net for metric size plugs.

This project just keeps getting bigger and bigger:lick:

[Pop's Z]

Here's what I did and it works perfectly with no leaks. Remember the air rail seals like a flare fitting on small 4" pipes inside the exhaust manifold.

1) remove the air rail from the exhaust manifold.

2) cut off the pipes from the air rail where they enter the fittings that go into the exhaust manifold (notice they have a rounded fitting on the exhaust side).3) weld those fittings bak in so they are snug inside the "nuts" ie: weld them on the outside and close the holes (I had them brazed).4) pull out the flared 4" pipes from the exhaust manifold.5) cut those off to about 3/4".6) replace them back into the exhaust manifold (I used a pencil to hold them as I put them back in).7) replace the welded up fittings in the exhaust manifold (I used anti-seize to make future removal easier. This process seals the pipes and the fittings. Feel free to PM me if this is confusing, I'm sure I can make it even more confusing. It really is a straight-forward DIY.

Cheers, Mike

[e_racer1999]

if you guys were closer i'd just give you my mani that's already plugged

[obxtrainman]

The research I've done over the last two days has led me to believe the fittings are a " you aint allowed to remove me size". When I first looked at this situation; I thought to myself, cut them off short, crimp them , and solder them tight. My professional, anal retentive side then kicked in and said, do it right. Thats when I started to look into removing the contraption, and plugging it properly.

Well guess what? I want to see and hear my new carbs. I think I'll cut and seal them. I can always go back later and do it properly. I just don't want to get into removing whole engine with 50,000 origininal miles to make it pretty with paint and headers and new exhaust.

From what I did learn, the fittings were to stop us from removing smog control. Metric anything doesn't fit, nor SAE. That is just removing, not even concidering plugging. I knew all along, after removing, easiest plug would be to tap to SAE thread size. After three days of continually hitting it with blaster; then not even getting good fit with a decent wrench to remove them, I think I'll fall back and punt.

Buy the way, my new Ztherapy carbs are "sexier than socks on a rooster":laugh:

[sblake01]

From what I recall reading in a thread here, though I can't find it now, is that those holes are British pipe thread for whatever reason (Japanese car/British pipe thread?). From what I've learned while being an ACE 'Helpful Hardware' clerk over the past four+ years it that BPT has a slightly different taper to the threads than 'standard' pipe thread. But, as ta240 says, standard can be coerced to fit. However, since he used brass, I hope he never plans to remove them!

[xray]

Buy the way, my new Ztherapy carbs are "sexier than socks on a rooster":laugh:

Compete that look with some new gleaming coated headers and ditch the rusty exhaust manifold!

Check my pics in my sig link...MSA 6-1 with new ZTherapy SUs look pretty suh-weeet....

Steve

[e_racer1999]

and you don't have to remove the engine to replace the exhaust mani

[obxtrainman]

Compete that look with some new gleaming coated headers and ditch the rusty exhaust manifold!

Check my pics in my sig link...MSA 6-1 with new ZTherapy SUs look pretty suh-weeet....

Steve

I'd love to go ahead and swap out the mani for some gleaming new headers:laugh: However at this time, if I did, my wife would probably leave meLOL She is a chinese lady. She refers to my almost 35 year old classic sports car as "your trash car". I truely did buy this Z for her. I've already put a very conciderable amount of time and money into it. Along the way of working on this car. I said OK, since it's such a trash car, I'll keep it for me Honey Bunny. Something tells me after I do get everything completed. It will be more like, Kenny, my car looks so nice, thank you:stupid:

[xray]

I truely did buy this Z for her. I've already put a very conciderable amount of time and money into it. Along the way of working on this car. I said OK, since it's such a trash car, I'll keep it for me Honey Bunny. Something tells me after I do get everything completed. It will be more like, Kenny, my car looks so nice, thank you:stupid:

...Oh, thank you Honey Bunny...And if you're realllllllly nice, and tell me how wrong you were---you might get to ride in it. Maybe...