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1966 coup ht 390 fe engine seized

Discussion in '1955 - 1966 Classic Ford Thunderbird' started by Patdown45, Dec 11, 2017.

  1. I sent my 66 off to get body work done and the idiot left the car out in the elements without an air cleaner. When I got the car back the engine was seized, I drained a pint of water out of the oil filter. So drained out the muck, pulled the plugs, and filled cylinders with marvel for a week and built a tool to mount on balancer so after a week slowly got the engine freed up, flushed out all the marvel and put fresh oil filter in and she started up again. After running for a few more times changed the oil again it is running really rich really black plugs. Did a compression test dry was 155 to 160 and went up to 180 190 wet (oil added to cyl) I am guessing the rings were rusted to the walls and have scored the walls and are not sealing well. My question is can this engine every be good enough to drive without a rebuild as 150 to 155 is below spec for this engine is a 390. Ran thru 3 gallons of premium gas after running at idle for 30 or 40 minutes and a quick 5 minute test drive, does not idLe will stall very easy. Changing fuel tank and lines, and will check for vacuum leaks at base of carb. Looking to just get it running decent.
  2. fordrodsteven

    fordrodsteven Well-Known Member Gold Donor

    Are you saying that while it sat idling for 30 minutes it went through 3 gallons of gas? If that is so you are pouring raw fuel into and through the system. No way the car should burn up 3 gallons of gas while sitting idling for 30 minutes. The car should run okay as long as all the cylinders are somewhat within range to each other. I've had engines that ran just fine and all the readings (compression) were between 90 and 120. Your plugs are black and sooty most likely because of how much fuel is pouring in there. Are the plugs wet with oil or gas? Again my guess is gas. Clean the fuel filters and get (at minimum) a tune-up kit for the carburetor. Once you get it running pretty good I would then suggest possibly a full carburetor rebuild. I think your engine should be just fine.
    Patdown45 likes this.
  3. Thanks
    Thanks for the quick response, I am changing all the fuel lines and tank and tank sending unit as the old system is full of rust and crap, plus the old float was no longer able to float full of holes, once the tank gets here will start her back up and see if can improve the carb settings, may just throw a rebuild kit in it
  4. fordrodsteven

    fordrodsteven Well-Known Member Gold Donor

    I would also give it a Sea Foam treatment or two.
  5. captrick

    captrick Well-Known Member Lifetime Donor

    Hey Pat. If you got that compression with a dry engine then added oil to the cylinders and it came that is a good chance that the rings were frozen. Check the carburetor maybe the floats are stuck and that is why it is running rich. The engine should be fine with 155 lbs of compression. You might want to try Shell’s Rotolla T 15/40 motor oil next time. It is designed for heavy duty use in diesels and has a lot of zinc in it. Using Seafoam can’t hurt either. Good luck Rick
  6. Thanks for the tip. Can't wait for the new gas tank to arrive and get it installed, will probably give the carb a quick rebuild and make sure no vacuum leaks.

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