A.I.R. tube finish

[Peter S.]

What is the proper finish for the A.I.R. tube manifolds for a '69 350/350HP? Mine have fallen deeply in love with my exhaust manifolds, and I fear they are inseparable at this point. If anyone could recommend a finish that would be applied while on the manifolds I would greatly appreciate it.

[Mark G.]

Re: A.I.R. tube finish

Peter -

That would be black zinc plate with a minimum thickness of .0005 in. thick. Just enough to prevent rust.
Originals were bath plated to GM specifications.

Mark

[Peter S.]

Re: A.I.R. tube finish

Mark,

Are you referring to black chromate atop zinc plating? Unfortunately since the A.I.R. tube manifolds are securely rusted to the exhaust manifolds, I cannot separate and send them out for plating.

I'm wondering if some rust-oleum BBQ black will replicate it well, at least in color and shine.

http://www.rustoleum.com/product-catalog/consumer-brands/specialty/high-heat-spray/

[Dick W.]

Re: A.I.R. tube finish

What is the proper finish for the A.I.R. tube manifolds for a '69 350/350HP? Mine have fallen deeply in love with my exhaust manifolds, and I fear they are inseparable at this point. If anyone could recommend a finish that would be applied while on the manifolds I would greatly appreciate it.

Patience, good chemicals, and time will allow you to remove the tubes. Soak with good penetrating oil, heat, soak, heat, soak, heat, for several days before you attempt to remove the tubes.

[Peter S.]

Re: A.I.R. tube finish

Patience, good chemicals, and time will allow you to remove the tubes. Soak with good penetrating oil, heat, soak, heat, soak, heat, for several days before you attempt to remove the tubes.

Dick, thanks for the response. I haven't tried heat yet (have soaked for multiple days with liquid wrench), but thought heat would be ineffective since the manifolds routinely see extreme heat. The nuts are in an advanced stage of corrosion. Regardless, I'll give it a shot, thanks.

[Dick W.]

Re: A.I.R. tube finish

Dick, thanks for the response. I haven't tried heat yet (have soaked for multiple days with liquid wrench), but thought heat would be ineffective since the manifolds routinely see extreme heat. The nuts are in an advanced stage of corrosion. Regardless, I'll give it a shot, thanks.

Liquid wrench is not a very effective penetrating oil, several here sing praises about Kroil.

[Peter S.]

Re: A.I.R. tube finish

Liquid wrench is not a very effective penetrating oil, several here sing praises about Kroil.

Thanks again Dick, I placed an order.

Peter

[Terry M.]

Re: A.I.R. tube finish

Dick, thanks for the response. I haven't tried heat yet (have soaked for multiple days with liquid wrench), but thought heat would be ineffective since the manifolds routinely see extreme heat. The nuts are in an advanced stage of corrosion. Regardless, I'll give it a shot, thanks.

I have found Kroil to be useful, but I see a lot of people are singing the praises of a 50/50 mix of Acetone and Automatic Transmission Fluid. I have seen the results of several (less than scientific) tests where that mixture was rated tops. DO NOT GET THE ACETONE ON YOUR PAINT under any circumstances.

[Paul D.]

Re: A.I.R. tube finish

I have used KROIL before and it does work wonders, however rusty A.I.R. tubes may be at the miracles level. In addition to Terry's sugestion of acetone and ATF, I saw a product called Freeze-Off by CRC featured in a magazine and they said it worked great. I got some at a ACE HARDWARE but have yet to try it out. It claims to "crack rust" by way of "freeze shock action". I remember a mechanic in the dealership I worked many years ago would sometimes shoot Freon on problem fasteners. Chip.

[Peter S.]

Re: A.I.R. tube finish

Well gentlemen, I have literally spent months trying to remove the A.I.R. manifolds. I have used multiple tanks of propane, 1/2 a can of kroil, ATF+acetone, and with much success two cans of CRC Freeze-Off. I had success removing 6 of the 8. Unfortunately, it left one nut on each manifold. One nut snapped and I will need to drill and tap the exhaust manifold (I'm sure that will be a barrel full of monkeys). The other nut has folded in upon itself as my patience may have gotten the better of me.

My question: tapping the exhaust manifolds - is this a tapered thread? Anyone have an exact thread size?

New A.I.R. manifolds - how is the fit and qualify of the reproduction A.I.R. manifolds from the vendors (let's say Zip)?

Injector pipe extension tubes - These tubes (http://www.ebay.com/itm/1969-Camaro-...141213&vxp=mtr) are nearly 1/3 of those the vendors list. I am not entirely familiar with the extension tubes, and I cannot really tell the difference. I would really appreciate some guidance.

[Terry M.]

Re: A.I.R. tube finish

Well gentlemen, I have literally spent months trying to remove the A.I.R. manifolds. I have used multiple tanks of propane, 1/2 a can of kroil, ATF+acetone, and with much success two cans of CRC Freeze-Off. I had success removing 6 of the 8. Unfortunately, it left one nut on each manifold. One nut snapped and I will need to drill and tap the exhaust manifold (I'm sure that will be a barrel full of monkeys). The other nut has folded in upon itself as my patience may have gotten the better of me.

My question: tapping the exhaust manifolds - is this a tapered thread? Anyone have an exact thread size?

New A.I.R. manifolds - how is the fit and qualify of the reproduction A.I.R. manifolds from the vendors (let's say Zip)?

Injector pipe extension tubes - These tubes (http://www.ebay.com/itm/1969-Camaro-...141213&vxp=mtr) are nearly 1/3 of those the vendors list. I am not entirely familiar with the extension tubes, and I cannot really tell the difference. I would really appreciate some guidance.

Pete,
It will take some searching of the board (try AIR tubes -- note no periods). We have covered the thread size. It is NOT tapered -- which is why most commonly available pipe plugs fit poorly at best. It is a SPT - Straight Pipe Thread. The size and TPI was discussed in several earlier threads.

[Peter S.]

Re: A.I.R. tube finish

Pete,
It will take some searching of the board (try AIR tubes -- note no periods). We have covered the thread size. It is NOT tapered -- which is why most commonly available pipe plugs fit poorly at best. It is a SPT - Straight Pipe Thread. The size and TPI was discussed in several earlier threads.

Hi Terry,

I did perform a search and was able to find that big block tubes are 1/2-18; I could not find the small block thread sizes. I feel that they are most likely the same as the tube diameters appear the same. But, I really do not like to make assumptions. Another thread gave the impression that it is tapered with no clear cut answer - this is why I asked. I will spare you my diatribe on forum search functions.

Any opinion on repros or the pipe extensions?

[Joe L.]

Re: A.I.R. tube finish

Hi Terry,

I did perform a search and was able to find that big block tubes are 1/2-18; I could not find the small block thread sizes. I feel that they are most likely the same as the tube diameters appear the same. But, I really do not like to make assumptions. Another thread gave the impression that it is tapered with no clear cut answer - this is why I asked. I will spare you my diatribe on forum search functions.

Any opinion on repros or the pipe extensions?

Peter-------


Big block and small block fittings were the same size.

The tube extensions shown will work fine for you. I have no idea why they show those red caps on each end. These tubes need no caps, even in storage. Most of the Corvette parts vendors have them, too.

[John H.]

Re: A.I.R. tube finish

I did perform a search and was able to find that big block tubes are 1/2-18; I could not find the small block thread sizes.

Peter -

Both big-block and small-block air manifold tube nut threads are 1/4"-18 National STRAIGHT pipe thread (NOT tapered pipe thread).

[Peter S.]

Re: A.I.R. tube finish

Thank you very much for the info!