I just installed a Lunati 60303 hyd cam and went through the 30 min break in yesterday. Car made it through break in fine and everything sounded great. I went back and readjusted the valve lash/preload today and now the valvetrain seems considerably noisier. I used 1/2 turn past "0" lash both during the cam install and when readjusting. I was going to put another 1/2 turn preload on each lifter to see if it quiets down any. Is 1 turn preload ok or too much? Anything else I can do to quiet it down? Always had some ticking with my old cam but not this much.

One turn is more than it should need. 3/4 turn is ok when cold and 5/8 when hot. Make sure you are using the exhaust opening/adjust intake-intake closing/adjust exhaust method.

You might want to start checking cam lobes too.

I've used as little as .010, but that's risky. If it backs off you don't have much time to catch it. Nowadays I use .016-.017(1/3 turn on a 7/16-20 thread.)

I would'nt of re-tightened the preload unless you backed them back off first. If that is what you did then the noise is probably just a by-product of the lifter design used and they bleed oil pressure at idle speeds. My Comp 822-16's are noisy no matter what preload. So I use as little as possible.

Granted when I was breaking it in I was running at 2k most of the time so could that be why I didn't notice the noise then? After the 1/2 hr break in the car was nice and hot and I adjusted the idle down to normal and didn't have it running at idle long before shutting it down.

Today I was starting it cold and let it idle....never even tried spinning it up any because I was waiting for the valvetrain noise to go away. After a minute or so I killed it to go back through and check everything all over again. I had my brother in law go through them again and he found some I didn't preload enough. Started it back up and it was quieter but still louder than the 509 it replaced. That's when he said put another 1/2 turn on each to see if it helps.

We did go through using the exh openning adj intake, intake closing adjust exh method.

Should I go back in and set for 3/4 turn preload instead or just run it as is?

You can try it but no guarantees. Healthy spring pressures are going to bleed the lifters down pretty quickly. If it loses preload, you need to check the cam lobes. I hope it isn't that, but after 25 years of never having a cam go flat, I had my first last year. It can happen to anyone.

there is always thicker oil

How much preload depends on the type of lifter [ standard or short travel ] and whether you have iron or aluminum heads. Standard lifters can be set anywhere from .010 to a little over .060 and still work reasonably well. Given the tolerances on stock production engines they have to be pretty forgiving. Short travel lifters are not so forgiving and like .004-.010. Aluminum heads will generally grow .004-.006 so you have to allow for that. A useful thing to keep in mind is that most rocker arm adjusters use a 3/8 in. fine thread so one full turn is equal to .042. I set preload when assembling the engine. Very seldom is there any need to go back over them.

Always used 1/4 turn on my XE295HL Comp hydraulic....never came out of adjustment and only had the typical fast ramp clatter....No need to go 1/2 or 3/4 turn...that's too much.