Valve noise after new heads installed
Thread Starter
Racer
Joined: Feb 2009
Posts: 343
Likes: 0
From: San Diego CA
Have you checked for clearance between the rocker arms and valve covers? I'm wondering if a small difference in the mounting height of the rockers on the new heads relative to the rail height for mounting the valve covers hasn't put the rockers in contact with the valve covers.
Well, I just saw the post above mine- I scanned quickly but missed that one. It looks like we're trying to say the same thing in a slightly different way.
Well, I just saw the post above mine- I scanned quickly but missed that one. It looks like we're trying to say the same thing in a slightly different way.
Thread Starter
Racer
Joined: Feb 2009
Posts: 343
Likes: 0
From: San Diego CA
Drifting
Joined: Jan 2006
Posts: 1,540
Likes: 12
From: TX
I would follow these to a tee. Different lifters require different preload. A comp high energy requires 1/2 to 3/4 turn preload. A Comp Pro Magnum requires zero to 1/8 turn preload. This is the correct method and adjustment preload for your lifters. This is the only way I would set them. That is just me.
http://www.cranecams.com/?show=techarticle&id=2
Crane recomends 1/2 to 1 full turn past zero.
Hydraulic Lifters Can Be Adjusted at Any Engine Temperature Since hydraulic lifters can compensate for thermal expansion of the engine, the adjusting can be done with the engine cold; hot adjustment is not necessary.
Adjusting Hydraulic Lifters for Proper Preload
In order to adjust the preload, the lifter must be properly located on the base circle or "Heel" of the lobe.
At this position the valve is closed and there is no lift taking place. You will need to watch the movement of the valves to determine which lifter is properly positioned for adjusting.
1. Remove the valve covers, and pick a cylinder that you are going to set the preload on.
2. Hand rotate the engine in its normal direction of rotation and watch the exhaust valve on that particular cylinder. When the exhaust valve begins to open, stop and adjust that cylinder's intake rocker arm. (Why? Because when the exhaust valve is just beginning to open, the intake lifter will be on the base circle of the lobe, the correct position for adjusting the intake.)
3. Back off the intake rocker arm adjuster and remove any tension from the pushrod. Wait a minute or two for that hydraulic lifter to return to a neutral position. The spring inside the lifter will move the pushrod seat up against the retaining lock if you give it time to do so. (If you are installing brand new lifters they will be in the neutral position when they come in the box.)
4. Now spin the intake pushrod with your fingers while tightening down the rocker arm. When you feel a slight resistance to the turning of the pushrod, you are at "Zero Lash". Turn the adjusting nut down one half to one full turn from that point. Lock the adjuster into position. The intake is now adjusted properly.
5. Continue to hand turn the engine, watching that same intake. It will go to full open and then begin to close. When it is almost closed, stop and adjust the exhaust rocker arm on that particular cylinder. (Again, when we see the intake almost closed, we are sure that exhaust lifter is on the base circle of the lobe.) Loosen the exhaust rocker arm and follow the same procedure described before in steps 3 and 4 to adjust this rocker arm.
6. Both valves on this cylinder are now adjusted, and you can move on to your next cylinder and follow the same procedure again.
http://www.cranecams.com/?show=techarticle&id=2
Crane recomends 1/2 to 1 full turn past zero.
Hydraulic Lifters Can Be Adjusted at Any Engine Temperature Since hydraulic lifters can compensate for thermal expansion of the engine, the adjusting can be done with the engine cold; hot adjustment is not necessary.
Adjusting Hydraulic Lifters for Proper Preload
In order to adjust the preload, the lifter must be properly located on the base circle or "Heel" of the lobe.
At this position the valve is closed and there is no lift taking place. You will need to watch the movement of the valves to determine which lifter is properly positioned for adjusting.
1. Remove the valve covers, and pick a cylinder that you are going to set the preload on.
2. Hand rotate the engine in its normal direction of rotation and watch the exhaust valve on that particular cylinder. When the exhaust valve begins to open, stop and adjust that cylinder's intake rocker arm. (Why? Because when the exhaust valve is just beginning to open, the intake lifter will be on the base circle of the lobe, the correct position for adjusting the intake.)
3. Back off the intake rocker arm adjuster and remove any tension from the pushrod. Wait a minute or two for that hydraulic lifter to return to a neutral position. The spring inside the lifter will move the pushrod seat up against the retaining lock if you give it time to do so. (If you are installing brand new lifters they will be in the neutral position when they come in the box.)
4. Now spin the intake pushrod with your fingers while tightening down the rocker arm. When you feel a slight resistance to the turning of the pushrod, you are at "Zero Lash". Turn the adjusting nut down one half to one full turn from that point. Lock the adjuster into position. The intake is now adjusted properly.
5. Continue to hand turn the engine, watching that same intake. It will go to full open and then begin to close. When it is almost closed, stop and adjust the exhaust rocker arm on that particular cylinder. (Again, when we see the intake almost closed, we are sure that exhaust lifter is on the base circle of the lobe.) Loosen the exhaust rocker arm and follow the same procedure described before in steps 3 and 4 to adjust this rocker arm.
6. Both valves on this cylinder are now adjusted, and you can move on to your next cylinder and follow the same procedure again.
Thread Starter
Racer
Joined: Feb 2009
Posts: 343
Likes: 0
From: San Diego CA
Using the adjustment procedure in the post right above yours, the noise went down to a very tolerable level. I drove it about 50 miles or so last week but have been out of town ever since.
I'm back in San Diego right now and should put some good miles on her this weekend. It runs great but I'm still thinking the valves are a bit more noisey than they used to be.
But I''m kinda done over-analyzing it and want to drive it! I've been so afraid of screwing those expensive heads up that I haven't driven it much since they went on. But now that the valve noise has diminished to where I'm comfortable with it, I'm going to drive it.
When using that method I also wrenched them down another 1/4 turn from where I was setting 'em. The first two times I went 1/2 T past zero lash and now they are set 3/4 T past zero. Wish me luck!
I'm back in San Diego right now and should put some good miles on her this weekend. It runs great but I'm still thinking the valves are a bit more noisey than they used to be.
But I''m kinda done over-analyzing it and want to drive it! I've been so afraid of screwing those expensive heads up that I haven't driven it much since they went on. But now that the valve noise has diminished to where I'm comfortable with it, I'm going to drive it.
When using that method I also wrenched them down another 1/4 turn from where I was setting 'em. The first two times I went 1/2 T past zero lash and now they are set 3/4 T past zero. Wish me luck!
