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

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

  1. 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....:(
  2. sorry to hear that.
  3. 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
  4. 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.
  5. 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.
  6. Another update: it's been slow going as the misses lost her job, but I've been making progress. I polished and lapped the valves and installed new seals in the Trick Flows. I now have the engine on a stand and torn down for a quick re-ring. Everything looks to be in order except for cylinder #3 which had a broken compression ring which scratched the cylinder. The hone has most of the scratch out as of now and should completely clean out without too much issue. I will be setting up my dial bore gauge and bring it home from work to check the cylinders before reinstalling the pistons, but hope to have it back together before spring-I'm hoping to take it to Mustang Week in Myrtle Beach this year.... :cool:

    Only pic I have to show is of the polished valves....
    #6 LILCBRA, Feb 2, 2015
    Last edited: Feb 2, 2015
  7. Another update....

    I finally got the re-ring done and just dropped the engine in the car a couple days ago. There were a couple imperfections in the cylinders, but I am letting them slide as I don't have the funds for a complete run through and machine work. It is just more motivation to save up for a stroker like I want anyway. I did, however, spend a little money and got a new intake manifold to replace the Offenhauser 360 that has been on the engine for 20 years or more. I ended up buying the ProComp air gap knock off for less than $150. I will be posting pics and giving a quick run down of it in a separate post. After many Google searches turned up nearly nothing but "don't buy it, it's un-American" posts, I am sure someone out there will appreciate some info before biting the bullet and buying it. Anyway, I should have it up and running in the next week or so.... :)
  8. I forgot about this post!!!

    ¨Anyway, I should have it up and running in the next week or so....¨

    Well, that didn´t happen, did it?!?

    ¨I'm hoping to take it to Mustang Week in Myrtle Beach this year.... ¨

    Or that!! I´m hoping to change this scenario in 2016!! I hope some other IIs will join me!!
  9. I haven't been to a big Ford/Mustang gathering since World Ford Challenge 6 in 2003.
    Depending on what goes on this next year, I might go.
    LILCBRA likes this.