Problem # 1 I don't know exactly what cam I have. I was told (didn't see the cam card) 550 lift 235 duration hyd roller cam, stock ratio 1.7 G.M. roller rockers.
Problem # 2 rockers have sounded noisy since day one, I took it back to engine builder he said it sounds normal, 2000 miles on motor now. Sounds more like the solid lifter cam I took out!
Problem # 3 How do I set or at least check the lifter preload?

As stated by Crane Cams:

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 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.

Note that in those instructions they didn't make any distinction between a hydraulic flat-tappet setup, and a hydraulic roller one. That's because they are both done the same way. So if you know how to adjust a non-roller cam, you also know how to do a roller. It's no different.

Roller rockers are often noisier than stock-type ones; some more so than others. Generally, the noise is fairly evenly distributed throughout the engine: not a couple of them clacking loudly and the rest quiet, but rather, all of them making about the same amount of noise. If it's like that, maybe a kind of louder whirring sort of sound than you're accustomed to, they're probably fine.

Crane has reported some tech info before pertaining to hyd rollers and alum heads...since there are so many brands of alum heads these days that on occation alum head engines may to require alittle more lifter preload on them vs an iron head engine.

It's the same theory as mech cams and alum heads..in that they require a tighter cold lash to achive the correct hot lash..... the same goes with the hyd rollers with alum heads may require a bit more preload vs iron heads.

I'm sorry but I am not familiar with your combo and have no idea what heads you are running so this may be a mute point in your case or even if preload is the cause of your valve train noise.

Originally posted by RB69SS396Conv:
Note that in those instructions they didn't make any distinction between a hydraulic flat-tappet setup, and a hydraulic roller one. That's because they are both done the same way. So if you know how to adjust a non-roller cam, you also know how to do a roller. It's no different.
:eek: :eek:

Originally posted by MY FYN 79:
As stated by Crane Cams:

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

Same way to get to the adjustment point for hyd. or solid but the rest of the procedure is different. Preload = hyd., lash = solid.

What's all that about?

Do you know something about how a hydraulic roller and a hydraulic flat tappet differ in their adjustment techniques, or what?

Or perahps I should consider the source, and ignore the comment.

Originally posted by RB69SS396Conv:
What's all that about?

Do you know something about how a hydraulic roller and a hydraulic flat tappet differ in their adjustment techniques, or what?

Or perahps I should consider the source, and ignore the comment. No problem, I'm just old and blind. I somehow read hydraulic flat tappet and saw solid flat tappet. I don't get the consider the source though. Sorry if you don't like the source, my mistake.

;) OK, these things happen to us all once in a while, I guess. I guess with all this uninformed bickering we've had here lately, I'm a little bit over-sensitive.

Thanks a lot guys, I have iron heads and the noisy rockers all do have a uniform sound, not just one making noise on it's own. But I will check them as noted above. Dave