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Anyone Know How To Remove The Air Tubes Inside The Air Injection Ports On Dauntless Heads?

Discussion in 'Early CJ5 and CJ6 Tech' started by jeraldt, Nov 21, 2020.

  1. jeraldt

    jeraldt Member

    So I am wrapping up the rebuild on a 225 V6 for my 65 CJ5. The heads I ended up with have air injection ports that I want to plug. So I purchased the correct plugs to do that. BUT there are air tubes inside those ports and its a big tougher than I expected. Tried threading them, and using easy out, but the metal is really soft and wont take threads, and easy out wont bite into it and make them turn. Anyone have any tricks to getting those little suckers out? Theses just got to be an easy way that I dont know about (hoping)

    Thanks Guys!
     
  2. Twin2

    Twin2 not him 2024 Sponsor 2023 Sponsor 2022 Sponsor

    just plug hole . and not worry about them . you'll never see them
     
  3. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    I understood that's not his problem. He has air tubes broken off in the head.

    If you are willing to pay for the help, I expect your local automotive machine shop would make quick work of them. If I were removing them, I would try drilling the inside of the tube until I just had the threads left, then collapse what's left into the threaded port.
     
    SFaulken likes this.
  4. Keys5a

    Keys5a Sponsor

    As Tim ays above, drill them.
    -Donny
     
  5. jeraldt

    jeraldt Member

    Thanks for the comments. Wanted to post a couple pics for clarity. The first pic is the plugs I bought for the air ports. The second and third pics show the tubes in the air injection holes that have to be removed for the plugs to fit in the holes. And of course, this is my first time through a bolt by bolt restoration of a CJ5. So I figured this out AFTER its all assembled and put back in. So drilling makes me nervous. I guess I could turn the engine over making sure both valves are closed for that piston before I drill, but drilling on a head that's installed already just feels really wrong to me.
     

    Attached Files:

  6. jeraldt

    jeraldt Member

    Thanks for the comments. Wanted to post a couple pics for clarity. The first pic is the plugs I bought for the air ports. The second and third pics show the tubes in the air injection holes that have to be removed for the plugs to fit in the holes. And of course, this is my first time through a bolt by bolt restoration of a CJ5. So I figured this out AFTER its all assembled and put back in. So drilling makes me nervous. I guess I could turn the engine over making sure both valves are closed for that piston before I drill, but drilling on a head that's installed already just feels really wrong to me.
     

    Attached Files:

  7. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    No other options come to mind. Maybe someone else has a suggestion.

    I would take my medicine and remove the heads. Not that big a job. A little time and some new gaskets. You can leave the carb and other parts on the manifold and pull that off intact.

    If you leave the heads on and drill, I don't think the valves position will matter. Likely any chips will get blown out of the exhaust. Or you could put a long thin tube on your shop vac and vacuum out the cylinder after you are done. No idea how risky or practical this is.
     
    jeraldt likes this.
  8. Big_Rob2020

    Big_Rob2020 Member

    Take your exhaust manifolds off and you will then have access the the bottom of the air tubes through the exhaust port. Use a flat head screwdriver to push up the tubes through the top. This will expose more of the tube so your easy out will bite into it. I will say that 4 of them will probably come out easily and two of them will be an A$$. The valves will not be in your way they are way in front of where the emissions tube come into the exhaust port, but if you aren't careful you could scar the valve stem as it is within reach of a screw driver.
     
    jeraldt likes this.
  9. jeraldt

    jeraldt Member

    Thank you! I will give this a try tonight and see what happens. Makes complete sense to me.
     
  10. Big_Rob2020

    Big_Rob2020 Member

    Cool! post pics for posterity, everyone always has this same question on this particular topic.
     
    jeraldt likes this.
  11. jeraldt

    jeraldt Member

    Well I was able to look into the exhaust ports and 1 tube out of 6 actually was into the exhaust chamber, and that one appeared to be a broken chard. So pushing them up from the bottom isnt going to work from what I saw. There is nothing to push up on. But I am starting to think I could push a rag into the port around the valve stem, and just drive the tube the rest of the way into the chamber, and fish it out with a magnet, then pull the rag out, vac or blow out any metal dust and Viola'. But so far its only a theory and I would need to make sure the exhaust valve was closed so nothing is falling into the combustion chamber. From sticking a mirror in the exhaust chamber I cant see anything stopping the tube from being pushed down into the exhaust chamber in the head so I can retrieve it. The only other way I can see, is to drill them out. I ran out of time tonight, so I will have to pick it up tomorrow.
    Another thing I am pondering is the purpose of the long protrusion on the plugs. If it weren't for those, I could just screw them into the heads and leave the tubes alone. I am not sure the purpose of them, instead of just a standard plug. I am going to email the mfr and see what kind of response I get.
     
  12. 45es

    45es Active Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Base on this comment, you are saying the threads within the head are accessible. If that's the case, why don't you just use a standard pipe plug? I would expect the threads to be NPT.
     
    jeraldt likes this.
  13. jeraldt

    jeraldt Member

    I am wondering the same thing. Since threads are exposed, why not just use a pipe plug or cut the tip off the plugs I bought. But I dont know what the purpose in the tip is yet, I have asked the supplier. Hope to hear back soon. upload_2020-11-23_20-30-21.png
     
  14. Fireball

    Fireball Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    They don't look like pipe threads. I'm guessing the sealing surface is at the step and the extended section is to help center the sealing surface.
     
    jeraldt likes this.
  15. Big_Rob2020

    Big_Rob2020 Member

    So you need to know a few more things here. The tubes are brass (therefore non ferrous) and they were originally designed to extend into the flow of exhaust gases, this was a rudimentary first generation sensor for environmental purposes. I am thinking maybe someone attempted to remove them at some point or your engine has high enough mileage that the extension of the brass tube eroded. The plugs you purchased will not fit if there is any remnant of the brass tube left. Have you tried to install them in all of the ports? Also you very well could drive them down into the exhaust chamber and get them out that way, BUT I have never done it that way without having the cylinder heads off and the valves removed. I ran into this same issue once on a higher mileage 225 where I could not push the tube up any. So I went ahead and did a top end and that was really the only way I was going to get them out. As far as the extension on the end of the plug you purchased, they are there to fully elongate down into the tube to be flush with the top of the exhaust port. If you didn't have the extension you would create air flow turbulence in the exhaust stream, which it already had from the air emissions tubes. So is it necessary? no not really it will still run, but then you have to ask yourself why are you doing this if your making no improvement.

    Just my two cents hope it helps.

    Rob
     
    jeraldt likes this.
  16. Steve's 70-5

    Steve's 70-5 Active Member

    I think I took the plugs out. Welded the hole up in them and reinstalled. I think a 1/2 inch bolt will work

    You are working on the exhaust side of the engine. So when running, anything in there should be blown out.
     
    jeraldt likes this.
  17. Big_Rob2020

    Big_Rob2020 Member

    The threads are not standard, the plugs are an oddball size they were originally for the sensor that went to them. I couldn't tell you what the size is but they are extra coarse thread which is what makes them sort of odd ball.
     
  18. 45es

    45es Active Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Interesting. It was my understanding the ports were created for use with the exhaust air injection system designed to meet the California emission requirements of the mid-1960's.

    What sensors were installed in these ports?
     
    jeraldt likes this.
  19. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Yes. Air injection into hot exhaust gas ignites unburned hydrocarbons. Lower HC emissions. The diverter valve cuts off the air when the throttle is closed and coasting, to prevent backfire in the exhaust. No sensors that I know of.
     
    jeraldt likes this.
  20. Big_Rob2020

    Big_Rob2020 Member

    Sorry I said sensors meant air tubes no such thing as a sensor in that year model to speak of.