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  • Valve Spring Removal - Bad Idea?

    I have a head-on valve spring compressor I am getting ready to try out. I am swapping cams, valve springs, and am at the point where I'm going to remove outer valve springs to check P-V clearance.

    My question - am I asking for trouble trying to do this with the cam box on like pictured? I have a means of pressurizing the cylinder, but it looks like there's the potential to lose the keepers down into the head. Try it out, or just pull the cam box? If I try it out, should I just be reaching down with a needlenose pliers to grab them, or are they steel where I could get them out with a magnet?

    Thoughts?







    sigpic
    Track Car Build | COM Sports Car Club

  • #2
    I have the same tool Brendan although I haven't used it yet. I think it would work good with a magnet. I've always used a magnet when disassembling the head. But reassembly might get a little tricky if you can't get your fingers down there. Since you engine is on a stand, maybe just lean it over at 90 so if they're dropped they won't go under the cam box.

    Hope this helps bud.

    Jake

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    • #3
      Maybe I'll just give it a try. If the keepers drop down into the head, I guess then I'll try it with the cam box off - I'll report back how it goes...

      Unrelated - when checking P-V clearance, how many valves do you check? Can I get away with 1 intake and 1 exhaust on cyl #1? Theoretically, shouldn't it be the same for every cylinder assuming the same valve lash? Cams are Schrick 284/276, stock pistons....

      - Brendan
      sigpic
      Track Car Build | COM Sports Car Club

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      • #4
        Well, just did a very unscientific test. The keepers are too big to fit between the upper retainer and tappet bore and fall down into the head

        Heading out to dinner and a couple beers, this project will commence in the morning...
        sigpic
        Track Car Build | COM Sports Car Club

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        • #5
          do it, the collets are magnetic. like jake said the fiddley part is putting it back together but thats what swear words are for

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          • #6
            Is this a tool that can be rented? I have a similar problem, in that the aft most exhaust valve in #4 cylinder happened to eject an adjustment shim upon a cold start-up, shooting it throught the ridge in the cam tray casting just above the bucket. It took a out a chunk of the casting ridge about the size of my pinky fingernail. My question is why and how a shim could be ejected in the first place.
            Someone has suggested that I remove the exhaust cam and with a magnet, remove the bucket and look in to hole to see if I broke a valve spring. The engine turns very freely, but of course with no compression in #4. What can I do now?
            sigpic
            4DAFUN
            Eric Adams
            Portland, Oregon

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            • #7
              Ok, I couldn't wait, but I can say that this setup works with the cam tray still on. The Snap-On spring compressor I am using is here:

              Compressor, Valve Spring, Universal
              Stock#: YA9140B
              http://buy1.snapon.com/catalog/item....re&dir=catalog

              I also have this fitting for my compression tester that I was able to use to pressurize the cylinder, I only needed 20psi (after removing the inner fitting to allow air to flow freely).

              Adaptor, Compression Gauge, Long Reach, 12mm x 1.25
              Stock#: EEPV307
              http://buy1.snapon.com/catalog/item....store&tool=all

              I was able to pressurize the cylinder, compress valve spring, remove keepers with a magnet, remove upper retainer and springs with magnet, replace inner spring, replace retainer, replace keepers with needle nose pliers (very carefully) and then make sure they seat with my finger tips, and then let the spring back up.

              My advice:

              Be very careful if you try this. I dropped a keeper into the head while trying to replace it. With the inner spring only, it can fit down the bore (I am using inner springs as test springs to check P-V clearance). I got lucky as the engine is on a stand - I rotated 180 degrees and the missing keeper came out. I held the valve spring compressor with one hand, and put the keeper into place using pliers using the other hand, put the pliers down, and made sure the keepers were seated with my fingertips.

              Also Make sure whatever cylinder you are working on is at TDC - that way if the valve does drop, it doesn't go down into the cylinder, just fractions of an inch until the valve contacts the top of the piston.

              More to follow... Checking P-V clearance for an intake and an exhaust valve for cylinder #1 tomorrow. Still wondering if I need to check the other cylinders / valves - would love to hear opinions. I guess it's not terrible to do so, I'm going to be replacing all the valve springs anyways...

              - Brendan
              sigpic
              Track Car Build | COM Sports Car Club

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              • #8
                Originally posted by 4DAFUN View Post
                Is this a tool that can be rented?
                Not that I know of.

                Originally posted by 4DAFUN View Post
                My question is why and how a shim could be ejected in the first place.
                Valve clearances way off? Never heard of this happening at idle.

                Originally posted by 4DAFUN View Post
                Someone has suggested that I remove the exhaust cam and with a magnet, remove the bucket and look in to hole to see if I broke a valve spring. The engine turns very freely, but of course with no compression in #4. What can I do now?
                No compression in #4 probably means bent valves in #4 at the very least. If you threw a shim, you're probably better off just pulling the cam tray and head to assess the damage. You don't need a spring compressor to do any of that.
                sigpic
                Track Car Build | COM Sports Car Club

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                • #9
                  On checking one or more cylinders for P-V clearance, I guess it depends on how much clearance you find on the first one. If you're way good then I think its reasonable to assume the others are good even with a little variance involved. But on your cams and pistons, it should be pretty close so I'd check them all.

                  FWIW, I found P-V clearance to be the tightest between 5 - 9deg ATDC on the intake side and 9 - 5deg BTDC on the exhaust side. Exact degree depends on where the cams are timed too.

                  Jake

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                  • #10
                    This is the spring compressor I have<click>. Same thing but a little cheaper than the Snap-on branded version.






                    Hope this helps,
                    Jake

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                    • #11
                      your probably doing this already, but, a wee blob of grease on the inside of
                      the collets (keepers) makes them a little less likely to wander off on reassembly.

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                      • #12
                        Originally posted by xworks View Post
                        your probably doing this already, but, a wee blob of grease on the inside of
                        the collets (keepers) makes them a little less likely to wander off on reassembly.
                        I was thinking the same thing -- a dab of grease on the inside of the keeper ought to be enough to "stick" it to the valve stem during reassembly. Still not easy to get them in there with the spring compressed (a magnetic pencil tool may help), but it ought to work.
                        The day ain't over yet....

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                        • #13
                          I thought I should report back, this setup works fine with the cam tray on, but getting the keepers back in using needlenose pliers made for a lot of cursing and swearing. I did manage to get all 16 outer springs removed without losing any keepers down into the head, but next time I am debating just pulling the cam box as I have the loctite I need to seal it up on-hand.

                          One question for this thread, the inner Valve Springs are still pretty stiff to use as test springs. Does anyone have a recommendation of a better (softer) spring to use for mock-ups?

                          A topic I'll continue in a separate thread, I am having P-V clearance issues. I measured roughly ~0.040" on both Intake and Exhaust at the 5-9 ATDC / BTDC ranges Jake mentioned above (I measured one cylinder and stopped). This is a stock motor, stock pistons, a head that was "cleaned up" a little at one point, and I was trying with stock cam gears and timing first. Next step, I need to look into Adjustable Cam gears to see if I can get the clearance I need. To keep this thread on topic, I posted on that issue here:

                          http://www.s14.net/forums/showthread...495#post456495
                          sigpic
                          Track Car Build | COM Sports Car Club

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                          • #14
                            Originally posted by Brendan View Post
                            One question for this thread, the inner Valve Springs are still pretty stiff to use as test springs. Does anyone have a recommendation of a better (softer) spring to use for mock-ups?
                            I agree. This is what I'm currently using <click>. They are a tad too big though (diameter) and can slip off the retainer. I think you could probably pick up something better and probably cheaper at Lowes, Home Depot, etc.. Here is a picture of mine in use:








                            Jake

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                            • #15
                              probably a bit of a long shot, if there's a truck breaker's near you
                              most large diesel engine thermostats have an ideal size spring to do the job.
                              These are from a Volvo 7 litre engine.....





                              Last edited by xworks; 12-30-2010, 04:27 AM.

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