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Is my 225 compression ok?

Discussion in 'Early CJ5 and CJ6 Tech' started by jccity6, Aug 24, 2009.

  1. Aug 24, 2009
    jccity6

    jccity6 knucklehead

    sacramento, ca
    Joined:
    Jul 5, 2009
    Messages:
    78
    Is my 225 compression ok?- add: it's fixed

    Couldnt find the actual specs for correct compression so could someone help the newb? I got 130,130,140,130,130,150. I looked around the forum a bit and found i should be closer to 150 or above on all of them. But are these readings something to worry about. It ran and idled great before the tear down so I was hoping to spend my $ elsewhere and wait to crack into the motor later and just drive it as is? Any thoughts?
    Always appreciative,
    JC:flag:

    Additional: I fixed it, I was just popping the motor not cranking until full compression. Now ereding are all averaging 190 with the lowest being 180 and the highest is just below 195.
    thanks for putting up with me:rofl:
    JC:flag:
     
    Last edited: Aug 24, 2009
  2. Aug 24, 2009
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    23,596
    Ok, mean is 135 psi.
    +/- 5% is 128 to 142.
    +/- 10% is 122 to 149.

    The most important issue is whether they are all close to each other. So, the single 150 cylinder is really the only outlier.

    Does it run now? The next test to do is to squirt a little oil into each cylinder through the spark plug holes and see if the values change much. if they all increase to around 150, worn rings are indicated.

    You can also do a leak-down test. You need a compressor and need to build a tool that screws into each plug hole. There are instructions several places on the net for building a leak-down tester.

    If it runs ok, I'd leave it. The compression readings aren't great, but they aren't that bad either. The engine may be worn, but from this info, not enough to justify tearing down a good running engine. IMO.
     
  3. Aug 24, 2009
    alexa

    alexa New Member

    Joined:
    May 1, 2008
    Messages:
    40
    I would take your numbers and leave it alone.
     
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