The Cobra Is Finally In Georgia, But.....

Discussion in '1974 - 1978 Mustang II Talk & Tech' started by LILCBRA, Jun 25, 2014.


  1. LILCBRA

    LILCBRA Member

    Joined:
    Dec 6, 2005
    Messages:
    323
    Showcase:
    24
    Albums:
    2
    Likes Received:
    8
    Trophy Points:
    19
    Location:
    Marietta, Ga
    We took a short vacation and went back to Iowa over the weekend. We visited with my family who we haven't seen in a year, had her 20 year class reunion, visited her family, traded our Expedition for a Suburban, loaded the Cobra on a U-haul trailer and came back to Marietta. But the Cobra had an issue before we moved that I never had the chance to fully investigate until yesterday. About a week before we moved, I had the carb off to change an accelerator pump diaphragm that was leaking. We drove it into town where it developed a miss. We limped it back home and looked around a little. We found that the #1 plug ground was pushed against the electrode effectively grounding the plug out. It didn't appear to be physically damaged which is what threw me. We bought new plugs, but it just didn't sound right to me. We drove it to my brother's storage unit and parked it until this last weekend. In the mean time, I bought a cheap bore-scope. So yesterday I put the bore scope to work. Turned the crank until the #1 cylinder was at BDC and ran the scope into the spark plug hole. I couldn't see the whole piston, but it looks like something got in there. There are 2 marks in the piston that I can see near the intake valve reliefs. So it looks like I will be tearing at least one head off and probably the whole engine from the car. I'm kinda bummed....:(
     
    #1
  2. The Big Blue

    The Big Blue Member

    Joined:
    Apr 4, 2014
    Messages:
    64
    Likes Received:
    0
    Trophy Points:
    7
    Location:
    Essex Md
    sorry to hear that.
     
    #2
  3. LILCBRA

    LILCBRA Member

    Joined:
    Dec 6, 2005
    Messages:
    323
    Showcase:
    24
    Albums:
    2
    Likes Received:
    8
    Trophy Points:
    19
    Location:
    Marietta, Ga
    Well, I finally tore the head off this morning. I'm not sure what I had seen with the bore scope, but I didn't see any damage whatsoever in that cylinder. What I did find, besides a little extra carbon buildup from running a little rich, was that the #1 cylinder had some kind of oil leak on the intake side. I am suspecting the intake valve seal, but can't rule out the intake gasket. I will be checking the valves in that cylinder just to be safe, clean everything up and put it back together! Sorry the piston pic is a little dark, didn't turn the flash on and was in a hurry to get to work....

    8-24-2014 497.jpg 8-24-2014 498.jpg
     
    #3
  4. The Big Blue

    The Big Blue Member

    Joined:
    Apr 4, 2014
    Messages:
    64
    Likes Received:
    0
    Trophy Points:
    7
    Location:
    Essex Md
    if your compression was good its most likely the valve seals, Fords were famous for valve seals gong bad and then having one spark plug foul out on a regular bases.
     
    #4
  5. LILCBRA

    LILCBRA Member

    Joined:
    Dec 6, 2005
    Messages:
    323
    Showcase:
    24
    Albums:
    2
    Likes Received:
    8
    Trophy Points:
    19
    Location:
    Marietta, Ga
    A quick update...

    Have both heads out of the car and took them to work. Filled the ports with the parts cleaner and found that the exhaust valve in the cylinder in question was leaking as well as a couple intake valves on the opposite head. I have cleaned the valves and seats, but don't see any damage, so I plan to lap the valves and check them again. Keeping my fingers crossed...

    Oh, they are Trick Flow heads, not Ford standard issue ;)
    And I will definitely be replacing the seals.
     
    #5

Share This Page