Valve Adjustment and "On The Rock" Setting

[kings1527]

So I'm adjusting my valves right now and I took a wrong turn somewhere on something pretty simple. As the manual says, you want to move either number 5 or number one 'on the rock'. If I'm 'on the rock', then neither the intake or exhaust arms of that particular cylinder should move, correct?

Here's what I have right now:

-number 5 inlet = doesn't move (spring is compressed in relation to the other inlet valves)
-number 5 exhaust = moves

-number 1 inlet = moves
-number 1 exhaust = doesn't move (spring is compressed slightly in relation to the other exhaust valves)

If I move everything one full rotation, it basically reverses itself. I'm trying to get set up on the rock to where neither number 5 or number one arms will move but I'm not sure where to go with this. My question is this:

1) Given my positions above, which is on the rock? Number 5 or number 1?

2) If I'm on the rock, what can I see visually if I'm looking inside? Will the springs be compressed or extended? If I can visually see something with the springs under the adjustment screw, then that will tell me which one is on the rock and where to start adjusting.

Thanks!

[Rich]

So I'm adjusting my valves right now and I took a wrong turn somewhere on something pretty simple. As the manual says, you want to move either number 5 or number one 'on the rock'. If I'm 'on the rock', then neither the intake or exhaust arms of that particular cylinder should move, correct?

1) Given my positions above, which is on the rock? Number 5 or number 1?

2) If I'm on the rock, what can I see visually if I'm looking inside? Will the springs be compressed or extended? If I can visually see something with the springs under the adjustment screw, then that will tell me which one is on the rock and where to start adjusting.

1) Neither, at least not for your work. One of #5 and one of #1 are on the rock in that example and that's not useful here.
2) See below.

"on the rock" means the rockers in question are riding on some part of the pair of cam lobes listed. Maybe only a little bit but you have to see that the rocker has moved from the closed-valve position. The do not both need to be full open just partially open, even just a bit. Yes, the valve will have "moved" while you got it to that position. No, the rocker at that point will not be able to "move" because it's pushing the valve open a little.

For your #5 cylinder example set the crank/cam position until BOTH the I5 and E5 (inlet and exhaust rockers for #5) rockers are tight - on the rock - with BOTH of them riding on some raised part of their cam lobes and pushing on the valve springs.

With that position set you can then set the rocker arm clearance for I4 and E6 rockers. And NOT for any of the #5 rockers. And so on around the top end. Have fun.

[Rich]

And one trick for getting the cam position where you want it is to put the car in 2nd or 3rd, ignition off, and safely push it bit by bit until the stars align for you.

Since you have a manual transmission...

Then put the tranny in neutral, block the wheels and go for the first two rockers which, as you see on in the manual, are each on just one of the other two cylinders on that bank, the two cylinders that do not have BOTH of their valves on the rock.

Lather, rinse, repeat.

[kings1527]

1) Neither, at least not for your work. One of #5 and one of #1 are on the rock in that example and that's not useful here.
2) See below.

"on the rock" means the rockers in question are riding on some part of the pair of cam lobes listed. Maybe only a little bit but you have to see that the rocker has moved from the closed-valve position. The do not both need to be full open just partially open, even just a bit. Yes, the valve will have "moved" while you got it to that position. No, the rocker at that point will not be able to "move" because it's pushing the valve open a little.

For your #5 cylinder example set the crank/cam position until BOTH the I5 and E5 (inlet and exhaust rockers for #5) rockers are tight - on the rock - with BOTH of them riding on some raised part of their cam lobes and pushing on the valve springs.

With that position set you can then set the rocker arm clearance for I4 and E6 rockers. And NOT for any of the #5 rockers. And so on around the top end. Have fun.

Ok, I think I'm getting this. So all I need to do to get on the right track is to keep pushing the car forward until both I5 and E5 rockers are tight? Per the manual, I should get to that point by lining up the mark on the crankshaft pulley to the mark on the right on the timing cover plate marked '0'.

I could've sworn I did that and I'm worried that I might've made an adjustment that messed things up a bit. Is it possible to make an adjustment that would result in 1/2 of 5 on the rock and 1/2 of 1 on the rock?

[Rich]

Ok, I think I'm getting this. (1) So all I need to do to get on the right track is to keep pushing the car forward until both I5 and E5 rockers are tight? (2) Per the manual, I should get to that point by lining up the mark on the crankshaft pulley to the mark on the right on the timing cover plate marked '0'.

I could've sworn I did that and I'm worried that I might've made an adjustment that messed things up a bit. (3) Is it possible to make an adjustment that would result in 1/2 of 5 on the rock and 1/2 of 1 on the rock?

See new numbers inserted in quoted question above:

1. Yes, using Method 1 in the book you rotate the cam until any cylinder pair, like I5 and E5, are tight. On the rock. Both of them. Then on to other cylinders.

2. Sort of. First, that's part of Method 2 but it still applies. And remember, there are two '0' positions as noted. Each one of them allows you to adjust 6 of the 12 valves. A lot less bumping around since you need the cams at only 2 positions, not 6 positions. And no 'on the rock' issues arise with Method 2.

3. Don't know if that's possible. If you use Method 2 then any adjustments you might have screwed up can be undone. Method 2 will get you going.

Come to think of it I wonder why they bother showing Method 1.

You probably have this part figured: If you run out of room pushing the car forward just put it in neutral, push it back, re-engage gear and continue forward again...I forget which gear works best. You'll find one.

[kings1527]

Thanks. I guess it turned out that I didn't go forward enough to put them both on the rock. Easy solution. I was under the impression that if you move the crankshaft pulley to the '0' marker on the plate cover, that'd automatically put both the intake and exhaust on the rock but obviously it doesn't work that way.

Moral of the lesson: move the crankshaft pulley into position on the plate and each time you come up on '0' on the timing cover, check the intake and exhaust on either 1 or 5 and stop when both the intake and exhaust are on the rock. It might take a couple revolutions to get you there. I never knew that.

And 5th gear is the easiest to work with on a manual.

[David T]

Thanks. I guess it turned out that I didn't go forward enough to put them both on the rock. Easy solution. I was under the impression that if you move the crankshaft pulley to the '0' marker on the plate cover, that'd automatically put both the intake and exhaust on the rock but obviously it doesn't work that way.

Moral of the lesson: move the crankshaft pulley into position on the plate and each time you come up on '0' on the timing cover, check the intake and exhaust on either 1 or 5 and stop when both the intake and exhaust are on the rock. It might take a couple revolutions to get you there. I never knew that.

And 5th gear is the easiest to work with on a manual.

The methods in the Workshop Manual work but are overly complicated. Just crank the motor over and when you see a valve close go just a little more and you can adjust it. The main thing is you MUST have the valve ALL THE WAY CLOSED before adjusting it. Another tip is if you see one valve in a cylinder all the way open, you know the other one is all the way closed.

[kings1527]

Everything turned out great. Apparently, I got everything right. I can barely hear any chatter from the valves. It's a pretty easy job to do but it's easy to go down a wrong path, too! Just get that on the rock setting right.

[John U]

how can you tell if you have done this incorrectly?

[Ron]

If you get them too lose they will be loud. Too tight, it will 'backfire' (either way), which will burn an exhaust valve. It will run ruff either way, depending on how far they are off.
You can double check by turning the high point of each lobe 180º away from the rocker-cam contact point and check that the feeler slightly drags when you slide it through the gap.

[John U]

Thanks
I did this job a while ago, and although my car runs great it is starting to sound like an old VW bug....I'm guessing exhaust manifold gaskets?
Using a mechanics stethoscope on the valve covers yields no real ticking noise.

John