AIR Tree Manifold

[George C.]

What is the best method to block C3 AIR tubes holes in exhaust manifolds when reinstalling AIR tree manifolds?

[Ron W.]

Re: AIR Tree Manifold

I can't find the original post, but this solution was posted by John Hinckley.
Quote
"Over the years I've removed the EXTENSIONS from dozens of cars as part of disabling the A.I.R. system, and if you replace each EXTENSION with a #10 x 1/2" flat head stainless steel machine screw, the tube nuts on the air manifolds will seat at exactly the same depth as if the EXTENSIONS were still in place, as the tapered shape under the screw head fills the same area as the flare on the EXTENSION, and the joint is sealed".

[John S.]

Re: AIR Tree Manifold

George, not sure where I got the original recommendation, but I used 1/8-27 brass pipe thread plugs from my local hardware store. The cast holes in my manifolds were almost the perfect diameter prior to drilling. Taped all of the holes with a standard 1/8-27 NPT tap. They've been in for a little over two years with no problems. Turned in flush with the manifold they also worked well with the A.I.R. pipe flared fittings.