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Are these cams to worn?

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  • Are these cams to worn?

    So I picked up a parts motor, popped the valve cover off, and found what appear to be s4 cams in it. The owner has no idea as he never got the motor running. They appear to have a bit of wear buy does this wear seam to excessive? Measuring the lobes with a micrometer they are all within .04mm of each other at their peak.
    Attached Files
    - '93 S13 (the long awaited fun machine)
    - '05 E46 (the S13 fund evaporator)

  • #2
    Yea, that ridge looks really nasty. If your rockers don't match up exactly where the first ones did on those cams, you'll grind things up and probably kill both the cam and rocker.

    I'd run them for like a Lemons engine, but not an engine I gave a crap about.

    BTW - FSM has a service limit for wear, you want to see what the height of that ridge is, but I'm pretty sure it's well over FSM limits.
    '18 Chevrolet Volt - Electric fun hatch for DD duty!


    DefSport Koni Sleeve and Spring Perch Buy!!!
    http://www.nissanroadracing.com/showthread.php?t=5902

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    • #3
      Thanks for the opinion. I was kind of thinking that would be the consensus. Two of the rockers in this motor are pretty marred, assuming it still would be a great idea to use them with the already worn rockers either?
      - '93 S13 (the long awaited fun machine)
      - '05 E46 (the S13 fund evaporator)

      Comment


      • #4
        Honestly, those cams might not have more lift than stock at this point. You've got to divide adv. lift by the rocker ratio to get the additional cam lift. S4's probably have like... 1 mm more than stock? I forget what the rocker ratio is on an SR, but let's say 1.55. That's 0.6 mm more at the cam, and I'd say you probably have about that much wear or more.


        What was the guy doing, running the cheapest O'Reiley $1/qt oil for 15k mi? haha


        Although I have seen a few sets of JWT cams pop up looking like this, so maybe they're a little softer than Nissan OEM cams.
        '18 Chevrolet Volt - Electric fun hatch for DD duty!


        DefSport Koni Sleeve and Spring Perch Buy!!!
        http://www.nissanroadracing.com/showthread.php?t=5902

        Comment


        • #5
          After calculating measurements the with rockers being 1.55 (which is accurate) they still have a lift of roughly 11.7 give or take a bit. Which is significantly more than stock. But yah. I have no idea what he was doing to wear them so bad. This is the worst rocker and the lobe contacting that rocker.
          Attached Files
          - '93 S13 (the long awaited fun machine)
          - '05 E46 (the S13 fund evaporator)

          Comment


          • #6
            They're only surface hardened too, so they'll wear very quickly going forward.
            '18 Chevrolet Volt - Electric fun hatch for DD duty!


            DefSport Koni Sleeve and Spring Perch Buy!!!
            http://www.nissanroadracing.com/showthread.php?t=5902

            Comment


            • #7
              Wow, didn't realize that kind of wear was possible!
              ~1992 240SX, SR20/Koni track day car
              ~2016 M3, daily driver

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              • #8
                Originally posted by Def View Post
                I'd run them for like a Lemons engine, but not an engine I gave a crap about.
                hey HEY! 99% of Lemons racers actually prefer racing out on track than shlepping underneath their car working in the paddock.


                Throw them in the recycling bin. If you put them in a Lemons engine, I will axe kick you in the nuts.
                Core4 Motorsports
                CLICK HERE for Wilwood FSL6R Radial Bracket & Rear Wilwood BBK GROUP BUY
                S14 VQ AER Endurance Racing Team

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                • #9
                  Well I figured out what happened. I mean damn, someone just didn't give a hoot it seems. The engine has some decent parts (arp studs, tomei cam gears, worn jw s4s ext. But wow at this bottom end. The thing had fine compression on all 4 cylinders but it looks the bearings are done for sure. And the oil pickup was broke and just sitting in the oil pan....that explains a lot. I'll get my money out of this wreck but would you guys even try fixing the crank?
                  Attached Files
                  - '93 S13 (the long awaited fun machine)
                  - '05 E46 (the S13 fund evaporator)

                  Comment


                  • #10
                    Everything is likely toast given the state of the came.

                    I was going to say, blocked oil squirters on the cans will do that over a long period... or a broken oil pickup...
                    '18 Chevrolet Volt - Electric fun hatch for DD duty!


                    DefSport Koni Sleeve and Spring Perch Buy!!!
                    http://www.nissanroadracing.com/showthread.php?t=5902

                    Comment

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