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Smoky Engine

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  • Smoky Engine

    After my oil smoke experience last Sunday on the dyno under high load I asked around on other sites. I did not really get the impression that Zetecs are typically subject to ring flutter. At least nobody else has heard about it.

    Now, today I spent some time testing compression and leakage. All numbers are measured with hot
    engine and "wet" means with a spoonful of oil in the chamber:

    Cylinder Compression dry Compression wet Leakdown dry

    1 195 245 15% ("Green" range)
    2 165 240 45% ("Yellow" range)
    3 195 240 15% ("Green" range)
    4 195 270 30% ("Green" range)

    Looks like cylinder #2 isn't that great anymore. Looking up the numbers from 2 years ago the compression was very even (all cylinders around 200 to 205 dry).
    The Leakdown tester is a cheap unit from Harborfreight. Don't know
    exactly what the percentage means but it appears to confirm the
    compression test.

    I tried to identify the leakage path with a stethoscope but, while I
    barely can hear some air hissing in the tester feed hose, it seems to be
    too little to hear in either cam cover, exhaust or intake. No coolant
    bubbles, either.

    The "wet" compression makes me believe that the leakage is that one
    piston ring?

    Anyway, what should I do now? Just keep going until it breaks, engine
    re-build now or junk the lump and put something new in?

    Thanks,

    Gert

  • #2
    Gert, I'd just drive it like it is until it really degrades. ie: to the point where you notice it.

    Then you can build up a nice track/touring engine for it.
    Tom "ELV15" Jones
    http://PIErats.com

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    • #3
      I'll have a 2.0L Duratec for sale, eventually, maybe even at some point during the current Geologic era.:D
      Chris
      ------------
      A day you don't go a hundred is a day wasted

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      • #4
        Gert

        I believe you should fix it ASAP. Until you get it apart you don't really know what's wrong with it.

        If it's a stock easily replaced engine the decision might be different but with ported head, upgraded cams etc. a failure could damage these beyond repair.

        Besides you know that if it fails you'll either be at a track day or on a drive 200 miles from home.


        Doug

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        • #5
          Gert, if you are going to tear it apart, then please do it now so you are ready for NorCal 2008 ;)

          -John
          Westfield SEiW
          2.0L Duratec
          Throttle Steer

          Comment


          • #6
            Originally posted by JohnCh View Post
            Gert, if you are going to tear it apart, then please do it now so you are ready for NorCal 2008 ;)

            -John
            Already started.....

            Comment


            • #7
              You're fast...
              Westfield SEiW
              2.0L Duratec
              Throttle Steer

              Comment


              • #8
                Well, so far no smoking gun (smoking cylinder, that is...)
                The pistons and valves look pretty much O.K. from the outside, except for some hefty carbon deposits (see images), which may have been created by bad maps a while ago or maybe even the oil burning.

                Next thing is pistons out and look for any wear or breakage.

                Something I noticed is the cylinder walls are really smooth with minor vertical grooves. I thought they should have kind of cross-hatch honing pattern. Does anybody know if that is normal after a few years of wear or should I consider honing the bores to reconstitute the surface?

                Thanks,

                Gert
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