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Old 11-25-2014, 01:47 AM   #1
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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.
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Old 11-25-2014, 02:12 AM   #2
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Quote:
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.
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Old 11-25-2014, 10:58 AM   #3
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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!
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Old 11-25-2014, 05:08 PM   #4
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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.
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Old 11-25-2014, 05:16 PM   #5
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Quote:
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
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Old 11-25-2014, 05:27 PM   #6
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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
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Old 11-25-2014, 05:46 PM   #7
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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.

Quote:
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.
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Old 11-25-2014, 05:56 PM   #8
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Personally I find it easier/safer to do with the head on the car but that is just me.
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Old 11-25-2014, 05:58 PM   #9
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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...
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Old 11-25-2014, 05:59 PM   #10
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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.
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Old 11-25-2014, 06:07 PM   #11
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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.

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Personally I find it easier/safer to do with the head on the car but that is just me.
I second this.
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Old 11-25-2014, 07:17 PM   #12
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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.

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Old 11-25-2014, 10:21 PM   #13
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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.
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Old 11-26-2014, 08:41 PM   #14
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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).
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Old 11-26-2014, 09:06 PM   #15
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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...

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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.

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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.
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Old 11-26-2014, 09:12 PM   #16
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This wouldn't explain why rotating the camshaft in either direction would be so difficult as to cause the bolt to break.
Perhaps the cam caps were tightened down too hard? OP, did you clean, lube and torque them properly? Were there any points in the rotation where the cam spun freely or was there always resistance the whole way around?
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Old 11-26-2014, 10:13 PM   #17
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Perhaps the cam caps were tightened down too hard? OP, did you clean, lube and torque them properly? Were there any points in the rotation where the cam spun freely or was there always resistance the whole way around?
The cam was lubed with the Web Cam's lube that Bisi provided with the parts. Everything was cleaned and lubed by the shop, although I now regret not asking if they had torqued everything correctly. This was, as they admitted, their first ever F series head, but they had done many b series and d series heads before (I even saw one on their bench).

When the shop owner was showing me how he thought I should lash the valves (he spoke with certainty), the cam rotated with only some resistance, an amount that didn't alarm him or me at all. Even at home, when the screws in the rocker arms and the lock nuts are all loose, the cam rotates with that same amount of manageable resistance. After I started going through the sequence and setting clearances, then it became progressively harder to rotate the cam. Furthermore, only when starting at TDC, rotating 270 degrees clockwise, and setting clearances in the firing order (1-3-4-2), did it become too hard to rotate with my ratchet, and this happened precisely after setting cylinder 4 and moving to cylinder 2. I got it to rotate through 180 degrees, so it was at TDC, and that is where it would not go further, except to twist and snap the bolt in 2 pieces.

"Snap' is really the wrong word for what happened. I noticed the cam wasn't turning, but my ratchet was. I quickly took the bolt out entirely to see if it was okay. Most threads looked normal, but about four rows of threads near the head were quite spread out. My next thought was idiocy, "Well, I guess it's a special bolt with two levels of threads". I put it back in, tried to rotate again and that's when it split into two.

Johnl, I have those springs in there because I was recommended to put them in there along with the Bisi Level 2 cam I was purchasing. This is a drag race project, so I will be pushing it to the rev limiter, but I do have to drive it to the track, a two hour trip.

When ordering the cam with Janet on the phone, I decided to have her order a new cam from Honda instead of send mine as a core. I hope this isn't a, what I will call, "wagon r" cam. I'm starting to get worried, though.
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Old 11-26-2014, 10:42 PM   #18
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More usually it's the rpm increase that cause the bigger problem, but the cam grind can also affect valve bounce (with faster / higher lift), so even if the rpm are not raised it's possible that stiffer springs might be needed with a cam change. I'd pay more attention to what the cam maker says than to me...
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Old 11-26-2014, 10:54 PM   #19
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Originally Posted by af_1132 View Post
When the shop owner was showing me how he thought I should lash the valves (he spoke with certainty), the cam rotated with only some resistance, an amount that didn't alarm him or me at all. Even at home, when the screws in the rocker arms and the lock nuts are all loose, the cam rotates with that same amount of manageable resistance.
With no spring resistance (i.e. no valve opening occurring) there should be zero resistance to rotating the camshaft. If there is then you need to ascertain what's causing it.

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After I started going through the sequence and setting clearances, then it became progressively harder to rotate the cam.
Which is normal.

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Furthermore, only when starting at TDC, rotating 270 degrees clockwise, and setting clearances in the firing order (1-3-4-2), did it become too hard to rotate with my ratchet, and this happened precisely after setting cylinder 4 and moving to cylinder 2. I got it to rotate through 180 degrees, so it was at TDC, and that is where it would not go further, except to twist and snap the bolt in 2 pieces.
Which isn't normal.

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"Snap' is really the wrong word for what happened. I noticed the cam wasn't turning, but my ratchet was. I quickly took the bolt out entirely to see if it was okay. Most threads looked normal, but about four rows of threads near the head were quite spread out. My next thought was idiocy, "Well, I guess it's a special bolt with two levels of threads". I put it back in, tried to rotate again and that's when it split into two.
No such thing as a "two level" thread.

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When ordering the cam with Janet on the phone, I decided to have her order a new cam from Honda instead of send mine as a core. I hope this isn't a, what I will call, "wagon r" cam. I'm starting to get worried, though.
I'd be carefully checking that no springs are becoming coil bound near full lift. With a large increase in lift it's conceivable that this could occur, if so then it would require the spring seats on the head to be machined lower.
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Old 11-29-2014, 12:33 PM   #20
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Here we go: http://www.cb7tuner.com/vbb/showthread.php?t=43270

I will check for a coil bound condition on the springs when I do this properly. After reading the above thread, I believe that I was applying too much torque to the lock nuts after adjustments. That may have been part of the problem, perhaps.
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15.10 @ 90.42mph
The quest for 9s ceased, now the goal is a circuit track monster!
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