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F134 Exhaust Tappet Sticking

Discussion in 'Early CJ5 and CJ6 Tech' started by Scott Sherraden, Sep 30, 2020.

  1. Oct 9, 2020
    Scott Sherraden

    Scott Sherraden Member

    Kansas
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    Here is #3. You can see it isn't in very good shape especially towards the top/right in the photo above. This one will take more agressive cutting to refigure the angles.
     
  2. Oct 10, 2020
    Keys5a

    Keys5a Sponsor

    Florida Keys
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    Post #78 has the guide removed? Yes, all your seats have replacment hardened seats. You may only require one, maybe two turns of the cutter, if even that, to clean the seats. Don't let the seat get too wide. Always hand lap your valves after cutting fresh seats to confirm full sealing and to check the final width.
    -Donny
     
  3. Oct 10, 2020
    Scott Sherraden

    Scott Sherraden Member

    Kansas
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    Hi Donny, thanks for confirmation, I was thinking the exact same thing :) I'm playing with it this morning. I just finished getting all 4 of the old valve guides out. Next I'm going to be driving the new ones in...
     
  4. Oct 10, 2020
    Scott Sherraden

    Scott Sherraden Member

    Kansas
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  5. Oct 10, 2020
    Scott Sherraden

    Scott Sherraden Member

    Kansas
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    Here is the end result! It didn't take long at all to drive in the new exhaust valves, ream them (using an old valve stem and some lapping compound), cut the 31/46/60 degree angles, and lap. All 4 look exactly like this one, they all turned out great in my opinion. I have a 1.5mm contact patch there right in the center of the valve face. It doesn't get any better than that. And I'm pleased that all 4 ended up exactly the same.
     
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  6. Oct 10, 2020
    47v6

    47v6 junk wrecker! 2020 Sponsor

    Washington DC.
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    Man, if you can pull all this off and get a good running Fhead, could be serious inspiration for others. How did you remove the valve guides? How did you then press in new ones and get the valved centered?
     
    Scott Sherraden likes this.
  7. Oct 10, 2020
    Scott Sherraden

    Scott Sherraden Member

    Kansas
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    Hey if an idiot like me can do it, any of you can :)

    For removing the old valve guides, see the Youtube video several posts up above. I used some fine thread 3/8 threaded rod, and grade 8 nuts/washers, to draw the old valve guides up and out of the block. Sounds easy but that took me at least 3-4 hours to get everything figured out and done.

    Putting in the new valve guides was the fastest and easiest part of the entire job. Using an old vintage 3/8 valve guide driver from Ebay, you just hammer them in. Seriously that part took me about 1 minute per valve guide. A few good strokes with a ball peen hammer and they are done.

    Getting the valve centered isn't really an issue. Once the new valve guides are in, that establishes the "new" center. Then, I used the Neway valve seat cutters to cut a new concentric seat using the new valve guides as a reference.

    After that, I just lapped the new valves, cleaned everything up and reassembled with the springs, etc. And the final step is re-setting the valve clearances.

    Now I'm busy getting the head back on... hope to have this all up and running within a few days. I have a few other jobs I want to do while it's apart, including new mount for the alternator, redo the leaky oil pan gasket, and install a new seal and yoke on the rear of the transfer case so it doesn't leak quite as bad.
     
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  8. Oct 10, 2020
    Scott Sherraden

    Scott Sherraden Member

    Kansas
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    Oh and now that all this is done, I'm hoping the exhaust valves will outlive me, so I'll probably sell and make someone a good deal on all of the tools I bought to do this job :)
     
    Glenn likes this.
  9. Oct 10, 2020
    Keys5a

    Keys5a Sponsor

    Florida Keys
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    That looks like a nice seat from the lapping, well centered on the valve face. Did you have to ream the guide after installation? Those hardened seats already in the block saved a lot of time/work.
    Nice work -Donny
     
  10. Oct 11, 2020
    47v6

    47v6 junk wrecker! 2020 Sponsor

    Washington DC.
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    I’m truly impressed. Way back 25 years ago before internet, my local 4x4 shop told me what you have done was impossible. .. I, unfortunately believed them. Stoked you’re making this happen. Stoked you’re showing us it can be done .
     
    Fireball likes this.
  11. Oct 11, 2020
    PeteL

    PeteL Member 2020 Sponsor 2019 Sponsor

    Hills of NH
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    Honing the guides with abrasive compound? I don't recall anyone "reaming" guides that way. Maybe for the final fine finish after reaming.

    Is that 'lapping' method a real thing?
     
    Last edited: Oct 11, 2020
  12. Oct 11, 2020
    Keys5a

    Keys5a Sponsor

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    Guides need to be finished with a reamer. Lapping with abrasive compound finishes the valve face to the individual seat.
    -Donny
     
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  13. Oct 11, 2020
    Scott Sherraden

    Scott Sherraden Member

    Kansas
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    A machine shop would never do it the way that I did, using an old valve guide and abrasive compound to ream the valve guide. However I read about this on the internet so it must be true :) lol seriously, I have seen a few legitimate claims to doing it this way and people claim they have good results. SO since I didn't have a 3/8 reamer, I tried it. I think it worked great to be quite honest. Time will tell, if my valve stems fail down the road I will let you know.

    You know us Jeep people make do with what we have! I think the method I used worked really great. I mean come on, it isn't rocket science, this isn't a 10,000 RPM sport bike or Porsche racing motor. It's a dang Jeep F134 motor. Use what you have, use common sense, get the job done, that's my philosophy :)

    If I'm wrong, and these exhaust valves blow up on me, I'll let you know. But I'm betting it's going to end up running great.
     
  14. Oct 11, 2020
    jeeper50

    jeeper50 jeeps 'till I die

    Gawja
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    Dec 20, 2007
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    Great progress! I replaced all my exhaust valve guides on my F head and my Lhead all guides, I did not use a Neway cutter but hand lapped the valves in with no valve seat inserts ,that was almost ten years ago and it's running fine.
     
    Last edited: Oct 11, 2020
    Scott Sherraden likes this.
  15. Oct 17, 2020
    Scott Sherraden

    Scott Sherraden Member

    Kansas
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    Hi all... just an update to close out this thread. I got everything put back together, and the engine is running GREAT!!!! It's much happier with all 4 cylinders firing. So that's a "happy ending" to this story :)

    Now that everything is running great, my winter projects will be a new Bestop Supertop soft top, and rebuild the transmission and transfer case. I plan to drop a lot of money with Novak for the rebuild kits for both :) Fun winter projects ahead.

    -Scott
     
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  16. Oct 17, 2020
    Fireball

    Fireball Well-Known Member 2020 Sponsor 2019 Sponsor

    Pullman, WA
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    Nice job!
     
  17. Oct 17, 2020
    PeteL

    PeteL Member 2020 Sponsor 2019 Sponsor

    Hills of NH
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    Have to admire your energy and initiative. :beer:
     
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  18. Oct 18, 2020
    Scott Sherraden

    Scott Sherraden Member

    Kansas
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    If anyone needs to tackle their exhaust valve seats I plan to sell the cutting tools. I'll get them listed in the Classifieds section. Since I have hardened seats I don't anticipate having to do this job again.
     
    Glenn likes this.

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