Stuck valve?

Discussion in 'Maintenance Bay' started by Tom-D, Nov 21, 2017.

  1. Tom-D

    Tom-D Ejection Handle Pulled

    Joined:
    Feb 23, 2005
    Messages:
    26,631
    Display Name:

    Display name:
    Tom-D
    See anything wrong with the cylinder in the picture?
     

    Attached Files:

  2. Bill Jennings

    Bill Jennings Final Approach

    Joined:
    Mar 2, 2005
    Messages:
    8,723
    Location:
    Southeast Tennessee
    Display Name:

    Display name:
    This page intentionally left blank
    Pic one shows left valve closed, right valve stuck open, yet pic 2 shows both valves closed?
     
  3. Tom-D

    Tom-D Ejection Handle Pulled

    Joined:
    Feb 23, 2005
    Messages:
    26,631
    Display Name:

    Display name:
    Tom-D
    Second picture was after I heated the cylinder and allowed the valve to close to get the springs off. nothing particular about the burn pattern? absolutely no carbon in the middle of the combustion chamber.
     
  4. PaulS

    PaulS Final Approach

    Joined:
    May 29, 2007
    Messages:
    6,011
    Display Name:

    Display name:
    PaulS
    tough to tell from the pics but the valve on the right looks torched from about 1 to 4 o'clock.
     
  5. Let'sgoflying!

    Let'sgoflying! Touchdown! Greaser! PoA Supporter

    Joined:
    Feb 23, 2005
    Messages:
    14,776
    Location:
    west Texas
    Display Name:

    Display name:
    Dave Taylor
    Is this an optical illusion from pic2; looks like the grand canyon! 1.jpg
    @Tom-D
     
    Last edited: Nov 21, 2017
  6. Tom-D

    Tom-D Ejection Handle Pulled

    Joined:
    Feb 23, 2005
    Messages:
    26,631
    Display Name:

    Display name:
    Tom-D
    The valve guide was carbon-ed up bad enough I had to drive the valve out with a 2 pound sledge.
    That messed up the guide so bad I threw the cylinder away, the bore wasn't that good either.
    I have better cylinders to rebuild than this one.
     

    Attached Files:

  7. biplanebob

    biplanebob Pre-Flight PoA Supporter

    Joined:
    Dec 20, 2009
    Messages:
    75
    Location:
    PA
    Display Name:

    Display name:
    biplanebob
    In photos #1 and #3, is that a crack at the spark plug boss ?
     
  8. Tom-D

    Tom-D Ejection Handle Pulled

    Joined:
    Feb 23, 2005
    Messages:
    26,631
    Display Name:

    Display name:
    Tom-D
    no. just a camera glitch.
     
  9. Tom-D

    Tom-D Ejection Handle Pulled

    Joined:
    Feb 23, 2005
    Messages:
    26,631
    Display Name:

    Display name:
    Tom-D
    no just black carbon from burning auto.
     
  10. Checkout_my_Six

    Checkout_my_Six Final Approach

    Joined:
    Mar 4, 2007
    Messages:
    6,924
    Location:
    Maryland
    Display Name:

    Display name:
    Check_my_Six
    Do ya still need us to tell ya what to do wit dat?o_O
     
    mscard88 likes this.
  11. Tom-D

    Tom-D Ejection Handle Pulled

    Joined:
    Feb 23, 2005
    Messages:
    26,631
    Display Name:

    Display name:
    Tom-D
    That cylinder is already thrown away what else would ya do with it?
     
  12. GlennAB1

    GlennAB1 Ejection Handle Pulled

    Joined:
    Oct 5, 2015
    Messages:
    4,776
    Location:
    Home will always be Vandalia, OH
    Display Name:

    Display name:
    GlennAB1
    Make another lamp.
     
    denverpilot likes this.
  13. Checkout_my_Six

    Checkout_my_Six Final Approach

    Joined:
    Mar 4, 2007
    Messages:
    6,924
    Location:
    Maryland
    Display Name:

    Display name:
    Check_my_Six
    call the FSDO....for coffee?
     
  14. Bill Jennings

    Bill Jennings Final Approach

    Joined:
    Mar 2, 2005
    Messages:
    8,723
    Location:
    Southeast Tennessee
    Display Name:

    Display name:
    This page intentionally left blank
    So, caboned up. Due to using Mogas or just too rich?
     
  15. mscard88

    mscard88 Touchdown! Greaser!

    Joined:
    Oct 1, 2015
    Messages:
    16,887
    Location:
    Alabama
    Display Name:

    Display name:
    Mark
    [​IMG]
     
  16. Tom-D

    Tom-D Ejection Handle Pulled

    Joined:
    Feb 23, 2005
    Messages:
    26,631
    Display Name:

    Display name:
    Tom-D
    It is my belief that the use of auto fuel allowed very hard carbon to build up on the valve stem. This made it impossible to remove the valve. I've seen it before but not this bad.
    Cylinders this bad aren't worth trying to fix, simply because of the cost of parts.

    When I overhaul an engine that had cylinders replaced I save the good ones for occasions like this. It's a shame to throw away 50 hour new cylinders when the customer wants all new, and many don't want their old cylinders back.
     
    Last edited: Nov 22, 2017
    edo2000 likes this.
  17. unsafervguy

    unsafervguy Line Up and Wait

    Joined:
    Aug 16, 2011
    Messages:
    989
    Location:
    Sw florida
    Display Name:

    Display name:
    bob
    see anything wrong? its not a lycoming?
     
  18. Tom-D

    Tom-D Ejection Handle Pulled

    Joined:
    Feb 23, 2005
    Messages:
    26,631
    Display Name:

    Display name:
    Tom-D
    Doesn't work like that.. ya got to have a badge to get near their coffee mess.
     
  19. mondtster

    mondtster Pattern Altitude

    Joined:
    Nov 25, 2011
    Messages:
    1,561
    Display Name:

    Display name:
    mondtster
    This seems to be one of those chicken or the egg syndromes. I wouldn't expect a valve guide with the proper clearance would allow enough carbon to build up to cause a sticky valve. So what happened first? Carbon buildup or valve guide wear that left enough space for the carbon to build up?

    What was the last fuel that got run through the engine? Unleaded or leaded? I had a valve stick on me in a Continental powered airplane that I fueled with 100LL after it had run hundreds of trouble free hours on unleaded car gas. It may have just been coincidental but I think the fuel was a contributing factor.
     
    edo2000 likes this.
  20. Tom-D

    Tom-D Ejection Handle Pulled

    Joined:
    Feb 23, 2005
    Messages:
    26,631
    Display Name:

    Display name:
    Tom-D
    Same thing here prior owner ran auto, this owner runs 100LL, some where over 100 hours by this owner.
    Wish I'd saved the valve. Hard diamond like carbon on one side of the stem, badly worn on the other, guide visibly out of round.
     
    edo2000 likes this.