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Setting Valve lash (clearance) "on the bench"

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    Setting Valve lash (clearance) "on the bench"

    I recently got my F22 head back from the machine shop, and it is time to properly set valve lash. I have the specs (.009" intake and .011" exhaust), and have even done one round of setting. The problem is that I think I did it wrong

    The only way you can turn the cam from the bolt holding on the gear is clockwise, or you will just loosen the bolt. This is what the machine shop told me I should do. It falls into place nicely in 90 degree intervals. I was setting lash in the firing order when going through this process: 1-3-4-2. Since I am rotating it clockwise instead of counterclockwise, should I actually be going through and setting the valve lash in the reverse of the firing order: 1-2-4-3?

    Any help or advice is appreciated.
    Last edited by af_1132; 11-25-2014, 03:59 AM.
    *** Think of others before thinking of yourself. ***
    ********** Spread love, not hate. ***********
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    MRT
    Selling on Ebay!

    15.10 @ 90.42mph
    The quest for 9s ceased, now the goal is a circuit track monster!
    Current fastest Laguna Seca Lap: 1:52.889

    #2
    Originally posted by af_1132 View Post
    I recently got my F22 head back from the machine shop, and it is time to properly set valve lash. I have the specs (.009" intake and .011" exhaust), and have even done one round of setting. The problem is that I think I did it wrong

    The only way you can turn the cam from the bolt holding on the gear is clockwise, or you will just loosen the bolt. This is what the machine shop told me I should do. It falls into place nicely in 90 degree intervals. I was setting lash in the firing order when going through this process: 1-3-4-2. Since I am rotating it clockwise instead of counterclockwise, should I actually be going through and setting the valve lash in the reverse of the firing order: 1-2-4-3?

    Any help or advice is appreciated.
    you can use an old timing belt wrapped around the outside of the gear to give yourself more grip, and just rotate the cam by hand. youd be able to rotate it the correct direction / counterclockwise.

    alternatively, you could rotate it clockwise 270degrees between each step, and follow the normal sequence. If you set up for Cyl 1, look closely at the cam lobe arrangement - then set up for the next in the sequence, and you can visually confirm that the cylinder you are about to work with is properly "set up" just like Cyl 1 was, before doing the adjustment.

    p.s. I find it easier to just do the adjustment once the head is mounted on the block, and the block in the engine bay. A lot more sturdy that way, otherwise it's easy to accidentally shift the head on your work surface and potentially damage it. I usually do it as soon as I put the timing belt & tensioner on, and use the crank pulley holder tool to rotate the pulley (without a bolt in it, just using the woodruff key to lock it to the crank). The only time this might be a problem is if your valve-to-piston clearance is tight, and they may interfere with each other as you rotate through the sequence. In that case, you could adjust all of the rockers to their loosest possible setting before assembling it, and then tighten each one back up to spec from there.
    Last edited by cp[mike]; 11-25-2014, 04:20 AM.


    - 1993 Accord LX - White sedan (sold)
    - 1993 Accord EX - White sedan (wrecked)
    - 1991 Accord EX - White sedan (sold)
    - 1990 Accord EX - Grey sedan (sold)
    - 1993 Accord EX - White sedan (sold)
    - 1992 Accord EX - White coupe (sold)
    - 1993 Accord EX - Grey coupe (stolen)
    - 1993 Accord SE - Gold coupe (sold)
    Current cars:
    - 2005 Subaru Legacy GT Wagon - Daily driver
    - 2004 Chevrolet Express AWD - Camper conversion

    Comment


      #3
      Thank you very much, Mike. I'm going to rotate counterclockwise using the timing bet idea. I really hope I didn't mess anything up rotating it the wrong way, eeek!
      *** Think of others before thinking of yourself. ***
      ********** Spread love, not hate. ***********
      ****Lift others up with kind and helpful words****

      F20A_CB7, I miss you, but I will see you one day.
      "Nothing a little prayer can't fix."


      MRT
      Selling on Ebay!

      15.10 @ 90.42mph
      The quest for 9s ceased, now the goal is a circuit track monster!
      Current fastest Laguna Seca Lap: 1:52.889

      Comment


        #4
        I should have waited for my new timing belt to come. Since I didn't have a timing belt to use to rotate it the correct way, I decided to take the 270 degrees clockwise approach. Everything was going well, until it was time to rotate the last 90 degrees past No. 1 TDC to get to No. 2. I could not get it over the hump, and then I tried again, and nothing moved but my ratchet. The bolt holding the cam gear had cracked in half.

        I should have waited, I should have been patient. Now I learned my lesson. Going to get a new bolt from Honda, and by then, the new belts will have arrived for me to use to do finish this properly.
        *** Think of others before thinking of yourself. ***
        ********** Spread love, not hate. ***********
        ****Lift others up with kind and helpful words****

        F20A_CB7, I miss you, but I will see you one day.
        "Nothing a little prayer can't fix."


        MRT
        Selling on Ebay!

        15.10 @ 90.42mph
        The quest for 9s ceased, now the goal is a circuit track monster!
        Current fastest Laguna Seca Lap: 1:52.889

        Comment


          #5
          Originally posted by af_1132 View Post
          I should have waited for my new timing belt to come. Since I didn't have a timing belt to use to rotate it the correct way, I decided to take the 270 degrees clockwise approach. Everything was going well, until it was time to rotate the last 90 degrees past No. 1 TDC to get to No. 2. I could not get it over the hump, and then I tried again, and nothing moved but my ratchet. The bolt holding the cam gear had cracked in half.

          I should have waited, I should have been patient. Now I learned my lesson. Going to get a new bolt from Honda, and by then, the new belts will have arrived for me to use to do finish this properly.
          ah crap! how did you have the head sitting? were the valves jamming against the table, or was it sitting on one of its sides? fortunately that should be an easy fix.

          good luck on the rest of the build


          - 1993 Accord LX - White sedan (sold)
          - 1993 Accord EX - White sedan (wrecked)
          - 1991 Accord EX - White sedan (sold)
          - 1990 Accord EX - Grey sedan (sold)
          - 1993 Accord EX - White sedan (sold)
          - 1992 Accord EX - White coupe (sold)
          - 1993 Accord EX - Grey coupe (stolen)
          - 1993 Accord SE - Gold coupe (sold)
          Current cars:
          - 2005 Subaru Legacy GT Wagon - Daily driver
          - 2004 Chevrolet Express AWD - Camper conversion

          Comment


            #6
            Originally posted by cp[mike] View Post
            ah crap! how did you have the head sitting? were the valves jamming against the table, or was it sitting on one of its sides? fortunately that should be an easy fix.

            good luck on the rest of the build
            Thanks.

            It was on a table, flat, but I had two layers of crumple brown paper underneath. I lifted it upside down and can see that the intake valves on NO. 2 are wide open, below the level of the head surface. I don't remember pushing down on the head with my other hand to keep things stable, but if I did that, I am going to drill a hole in my own head .

            When the timing belt comes, this will be done on a softer surface like my bed or the couch, rotating the correct way, and if it doesn't want to budge at some point, then I will wait until the head is on the car.

            Oi
            *** Think of others before thinking of yourself. ***
            ********** Spread love, not hate. ***********
            ****Lift others up with kind and helpful words****

            F20A_CB7, I miss you, but I will see you one day.
            "Nothing a little prayer can't fix."


            MRT
            Selling on Ebay!

            15.10 @ 90.42mph
            The quest for 9s ceased, now the goal is a circuit track monster!
            Current fastest Laguna Seca Lap: 1:52.889

            Comment


              #7
              Originally posted by af_1132 View Post
              The only way you can turn the cam from the bolt holding on the gear is clockwise, or you will just loosen the bolt.
              Probably not. The torque to which the sprocket bolt is tightened is likely to be significantly greater than the torque it will take to rotate the cam against the valve spring pressure, so using the bolt head to rotate the camshaft anti-clockwise is not likely to have loosened the bolt. If when rotating the camshaft anti-clockwise you had actually loosened the bolt, then once it had lost it's tightness further attempting to rotate the camshaft would have just easily rotated the bolt further in an obvious manner (but without rotating the camshaft, i.e. the bolt would just 'undo').

              With the head off I usually find I can rotate the camshaft just rotating the sprocket by hand, the spring resistance is quite strong but not huge. Be careful not to damage the head face working on the bench, rest the head on an old towel or whatever, not the bare workbench surface. If you're concerned that the bolt may have loosened, then once the engine is assembled just re-check the bolt torque.

              Originally posted by af_1132 View Post
              This is what the machine shop told me I should do. It falls into place nicely in 90 degree intervals. I was setting lash in the firing order when going through this process: 1-3-4-2. Since I am rotating it clockwise instead of counterclockwise, should I actually be going through and setting the valve lash in the reverse of the firing order: 1-2-4-3?
              It doesn't really matter in what order the clearances are set, as long as they all get done. Just rotate the cam until the pair of valves that you intend to set are closed and their rockers are sitting on the middle of the cam lobe 'base circle', and then set the clearance. Rotate the cam until the next pair of valves is closed (whichever pair that happens to be), and set them, rotate until the next pair are closed, and set them, etc. To keep track, just mark each valve with a marker pen after it's been set.
              Regards from Oz,
              John.

              Comment


                #8
                Personally I find it easier/safer to do with the head on the car but that is just me.

                Comment


                  #9
                  Originally posted by af_1132 View Post
                  Everything was going well, until it was time to rotate the last 90 degrees past No. 1 TDC to get to No. 2. I could not get it over the hump, and then I tried again, and nothing moved but my ratchet. The bolt holding the cam gear had cracked in half.
                  Something is very wrong. It shouldn't take that much force to rotate the camshaft unless something is jammed. Perhaps one of the springs is becoming coil bound before it is fully opened (though I'm at a loss as to how this could occur, and it would imply very careless head assembly with wrong parts). Maybe a valve is not closing but still protruding a long way into the combustion chamber (i.e. the 'clearance' is extremely negative, i.e. even with the rocker sitting on the lobe base circle the valve is still substantially open), which might cause an opening valve to contact the valve that is failing to close...
                  Regards from Oz,
                  John.

                  Comment


                    #10
                    Originally posted by wildBill83 View Post
                    Personally I find it easier/safer to do with the head on the car but that is just me.
                    I agree as well! I mount the head, install the timing belt, do the valve adjustment, then re-do the timing belt tensioner having rotated the engine a few times while doing the valve adjustment (good time to verify everything is perfect), then put all the covers on.

                    if you want to do them while the head is off, I'd suggest maybe having it sitting on its Intake side when rotating it, using all of the IM studs to hold it up. then drop it back down onto a towel when doing the actual adjustment. while rotating through the cycle, valves will certainly be sticking down well below the face of the head. I've never done a valve adjustment in particular, but that's usually what I do if I'm doing any valvetrain work on a removed head.
                    Last edited by cp[mike]; 11-25-2014, 08:05 PM.


                    - 1993 Accord LX - White sedan (sold)
                    - 1993 Accord EX - White sedan (wrecked)
                    - 1991 Accord EX - White sedan (sold)
                    - 1990 Accord EX - Grey sedan (sold)
                    - 1993 Accord EX - White sedan (sold)
                    - 1992 Accord EX - White coupe (sold)
                    - 1993 Accord EX - Grey coupe (stolen)
                    - 1993 Accord SE - Gold coupe (sold)
                    Current cars:
                    - 2005 Subaru Legacy GT Wagon - Daily driver
                    - 2004 Chevrolet Express AWD - Camper conversion

                    Comment


                      #11
                      Originally posted by johnl View Post
                      Probably not. The torque to which the sprocket bolt is tightened is likely to be significantly greater than the torque it will take to rotate the cam against the valve spring pressure, so using the bolt head to rotate the camshaft anti-clockwise is not likely to have loosened the bolt. If when rotating the camshaft anti-clockwise you had actually loosened the bolt, then once it had lost it's tightness further attempting to rotate the camshaft would have just easily rotated the bolt further in an obvious manner (but without rotating the camshaft, i.e. the bolt would just 'undo').

                      With the head off I usually find I can rotate the camshaft just rotating the sprocket by hand, the spring resistance is quite strong but not huge. Be careful not to damage the head face working on the bench, rest the head on an old towel or whatever, not the bare workbench surface. If you're concerned that the bolt may have loosened, then once the engine is assembled just re-check the bolt torque.



                      It doesn't really matter in what order the clearances are set, as long as they all get done. Just rotate the cam until the pair of valves that you intend to set are closed and their rockers are sitting on the middle of the cam lobe 'base circle', and then set the clearance. Rotate the cam until the next pair of valves is closed (whichever pair that happens to be), and set them, rotate until the next pair are closed, and set them, etc. To keep track, just mark each valve with a marker pen after it's been set.
                      You are correct. You can in fact turn the cam/cam gear counterclockwise without loosening the cam bolt. This is true whether the head is on the block or not.

                      Originally posted by wildBill83 View Post
                      Personally I find it easier/safer to do with the head on the car but that is just me.
                      I second this.




                      Comment


                        #12
                        I've done it both ways. In the past, even after doing it on the bench, I always rechecked it with the head installed. And nowadays I prefer just do it with the head installed.

                        You can also use the tool below to rotate the cam. The smaller one is kinda useless but larger one can be handy to have in the garage.



                        Comment


                          #13
                          Originally posted by johnl View Post
                          Something is very wrong. It shouldn't take that much force to rotate the camshaft unless something is jammed.
                          I think what I did was push down on the head with one hand, or a little of my back side, while rotating the cam clockwise. I was fighting the force of the intake valves that were lifting the head anyway (sigh). Now I need to check that I didn't bend any valves .

                          Keep in mind that I have Bisi Pro springs installed, so rotations are going to be harder to manage than with the stock springs.

                          Whenever I tried to rotate counterclockwise, the bolt would come loose, sooo, that means the shop probably did not look up the torque specs on that bolt.

                          I'm just going to loosen all the valve clearances and wait to set these clearances until the head is bolted down and the timing belt is in place. Doing this on a bench is proving dangerous and potentially costly (about $1500 is invested in that head). I'm going to take your advice, my good people.
                          *** Think of others before thinking of yourself. ***
                          ********** Spread love, not hate. ***********
                          ****Lift others up with kind and helpful words****

                          F20A_CB7, I miss you, but I will see you one day.
                          "Nothing a little prayer can't fix."


                          MRT
                          Selling on Ebay!

                          15.10 @ 90.42mph
                          The quest for 9s ceased, now the goal is a circuit track monster!
                          Current fastest Laguna Seca Lap: 1:52.889

                          Comment


                            #14
                            Originally posted by H311RA151N View Post
                            You are correct. You can in fact turn the cam/cam gear counterclockwise without loosening the cam bolt. This is true whether the head is on the block or not.
                            But, if rotating the camshaft with the head attached to the block, make sure that the pistons are nowhere near TDC. If any of the pistons are at (or near) TDC then valves may contact a piston as the camshaft is rotated...

                            And, at the risk of stating the obvious, never rotate the crankshaft using the camshaft sprocket bolts (always rotate the crank at the crank).
                            Regards from Oz,
                            John.

                            Comment


                              #15
                              Originally posted by af_1132 View Post
                              I think what I did was push down on the head with one hand, or a little of my back side, while rotating the cam clockwise. I was fighting the force of the intake valves that were lifting the head anyway (sigh). Now I need to check that I didn't bend any valves .
                              I'd be very surprised if that could cause substantial resistance to rotating the camshaft. I've rotated camshafts with the head on the bench a number of times, and all that happens is that any opening valve just lifts the head a little off the bench, even leaning on the head to prevent rotating the whole head.

                              Same for bending the stems, I just can't see it happening, the force it would take to do this will be way more than the force needed for any opening valve to lift the head off the bench (unless the head is clamped to the bench...).

                              Something must have been creating a great deal of resistance for the sprocket bolt to have broken before the camshaft would rotate further...

                              Originally posted by af_1132 View Post
                              Keep in mind that I have Bisi Pro springs installed, so rotations are going to be harder to manage than with the stock springs.
                              Are you intending to rev the engine to significantly higher rpm than the stock redline? If yes then you may need stiffer valve springs, if not then stiffer springs can do more harm than good. I can rev my stock 370,000km old engine to the rev limiter with no obvious sign of the valves 'bouncing', and preventing valve bounce is the only good reason to fit stiffer springs.

                              Even with stiffer springs, I doubt they could be stiff enough to cause an issue when rotating the camshaft.

                              Originally posted by af_1132 View Post
                              Whenever I tried to rotate counterclockwise, the bolt would come loose, sooo, that means the shop probably did not look up the torque specs on that bolt.
                              That does sound like the bolt may not have been tight enough. I would always torque such bolts making sure to use a liberal quantity of oil on the thread and under the bolt head.

                              This wouldn't explain why rotating the camshaft in either direction would be so difficult as to cause the bolt to break.
                              Regards from Oz,
                              John.

                              Comment

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