Removing Air Tubes From Manifold ?

[Zs-ondabrain]

When the CHP pulls you over for a roadside emissions compliance check LOOKING STOCK becomes a VERY good thing!

Kinda off topic, but, what is the year limit on emissions in California? In Washington, if your Basic Vehicle (passenger cars, truck, vans, SUV - under 8501 LBS) is 25 years old or older, you're Exempt from the emissions check.

Just wondering, in case we ever move to SoCal or something.

Dave.

I cut, folded and bronzed my 78' 510 tubes (L20B) I was in a hurry and very inexperienced at the time.

[Oiluj]

Kinda off topic, but, what is the year limit on emissions in California? .

In California, (from the DMV web page), model year 1975 and older for vehicles less than 14K pounds.

[Arne]

Just wondering, in case we ever move to SoCal or something.

No smog tests in Oregon if you are outside the Portland metro area, and not in Jackson County (Medford/Ashland). The rest of the state is free of such things.

[Mat M]

In California, (from the DMV web page), model year 1975 and older for vehicles less than 14K pounds.

Oh, don't get me started on that policy. I have been waiting 7 years for 1976 model years to be exempt. (they discontinued the 30+ year rolling exemption 3 months before my 76 would have been exempt - barstards!!!)

[Z train]

The exemption is for TESTING only.NO emissions equiptment may be removed from ANY vehicle.

And people ask why i left that Gestapo run state.

[Ttiger]

Oiluj, Do you happen to have the McMaster part number. I've been digging around on their web site and all I find is BSPT taps and dies, no bolts.

Thanks!

[snub260]

You can get Aero Kroil direct from Kano Labs 1-800-311-3374

[snub260]

you can get Aero Kroil direct from Kano Labs 1-800-311-3374

[Oiluj]

Oiluj, Do you happen to have the McMaster part number. I've been digging around on their web site and all I find is BSPT taps and dies, no bolts.

McMaster-Carr p/n 4810T192 1/4" BSPT Hex Head Plug, 304 S. Steel - $2.10 ea

or if you prefer

McMaster-Carr p/n 4810T182 1/4" BSPT Square Head Plug, 304 S. Steel - $2.22 ea

If you go to the McMaster-Carr website, type in the p/n in the upper box for the catalog page with pictures.

[pbatura]

So, is the consensus stock manifold?

The PO of my 76 L28 had cut the tubes off at the nut and filled with epoxy. I've got an extra manifold that I'm grinding off the nuts and will braze the hole from the port side. and will replace the current manifold.

Is this a reasonable approach?

[daddiodanger]

definately use PB blaster(Walmart) religiously. Kroil is my secret weapon, but it's expensive. I picked up a can at an industrial equipment supplier for like $10. It has never let me down so its worth it.

[Sailor Bob]

I am currently cleaning up a 73. I have to do the exhaust - it's about to turn to dust and looking down the road I am thinking about a street (midrange) cam, so working backward I figured I should start with a header and a 2.5 exhaust in order to acount for the future intentions.
Anyway I just ordered a coated header 3-2 and 2.5 turbo exhaust at MSA. Now I am scratching my head (top my shoulders - NPI), after reading this thread and Carl's comments.
Hope I did the right thing - shipping was over $100. Sucks to have to order everything cross country.

*A local circut racer cut the tubes close to the studs and crimped the tubes closed. The car was not used extensively after that so I can't say how well it worked out.

[vercingetorix]

"Cutting the stock exhaust pipe open at the "Y" and going to a larger diameter exhaust system, with a free flowing muffler will pick up between 12 and 15 HP. "

Mr Beck,
What exactly did you mean by this? Are you referring to the divder in the neck of the exaust manifold itself or something further down the tube?
I've never seen a stock setup so forgive my ignorance,
Best,
H Houghton

[motorman7]

Here's a pic of the exhaust air tube plugs I got from McMaster-Carr. They are 1/4" BSPT hex head and I think they look pretty nice.

With that big hex head, I'll be able to remove them if required...

Just for reference, anyone planning on tapping the holes out to install the original air galley should use the ¼”-19 BSPP tap. The BSPT will not go deep enough to allow you to start the threaded fittings of the air galley. Unfortunately, I ordered the BSPT tap and the fittings will not start into the holes. Got out my calipers and found that about half way up the tap, the thread max OD is 0.537”. The air galley fittings are 0.542” OD and will not thread into the smaller diamter. The upper portion of the tap is 0.545”, so that part will work. I will take a die grinder to the tap this afternoon and cut-off the lower, smaller diameter portion of the tap. This should make it possible to tap the hole to the right diameter, instead of popping another $20 for the BSPP tap. The tap can be purchased from McMaster-Carr as discussed earlier here.

[motorman7]

Cut the bottom 1/3 of the BSPT Tap and it worked perfect. Was able to run tap all the way into the hole. Attached the air galley into the manifold using some anti-seize copmpound for lube. Will install assembly in Silver Z today or tomorrow.

[GregP]

Just for reference, anyone planning on tapping the holes out to install the original air galley should use the ¼”-19 BSPP tap. The BSPT will not go deep enough to allow you to start the threaded fittings of the air galley. Unfortunately, I ordered the BSPT tap and the fittings will not start into the holes. Got out my calipers and found that about half way up the tap, the thread max OD is 0.537”. The air galley fittings are 0.542” OD and will not thread into the smaller diamter. The upper portion of the tap is 0.545”, so that part will work. I will take a die grinder to the tap this afternoon and cut-off the lower, smaller diameter portion of the tap. This should make it possible to tap the hole to the right diameter, instead of popping another $20 for the BSPP tap. The tap can be purchased from McMaster-Carr as discussed earlier here.

Was there a reason you had to tap the holes at all? Wouldn't the new air galley bolt right in?
I just sent out my exhaust mainfold to be ceramic coated and I was figuring I may need to tap the holes once I got it back so your experience with the tap will be very helpful.

[Kurbycar32]

I just cut the air tubes out and welded the holes shut. After grinding down the welds and repainting with exhaust paint the thing looks like a new stock part

[GreenZZZ]

When I did mine, I found bolts, not plugs. I locktight'd them in, cut them with a cutting disk on a dremmel and ground them down with a grinder. After which I painted with POR-20. Pretty happy with it...

Gallery Link

[sparegolfer]

My brother-in-law (84 Corvette, 56 Ford Pickup) works for Zep, and he gave me this product called Groovy and it works great. I took my 10/70's brake lines apart with it with no kinking! Just sprayed a little on it the night before, went back the next day shot a little more and whola, like a hot knife through butter.

[Koalia]

When I did mine, I found bolts, not plugs. I locktight'd them in, cut them with a cutting disk on a dremmel and ground them down with a grinder. After which I painted with POR-20. Pretty happy with it...

Gallery Link

Is that the "original" colour of the manifold? I've been planning to paint it with something, just dont know with what. Its rusty-poo'ish looking now.

[GreenZZZ]

Is that the "original" colour of the manifold? I've been planning to paint it with something, just dont know with what. Its rusty-poo'ish looking now.

The POR-20 looks almost identical to the color of the steal when it comes out of the sand blaster, so I guess its a bare steal look. You have to cure the paint so I popped it in the oven when the wife was out running errands, then ran a self clean cycle... "Hey honey, I cleaned the oven!"