Using GTX 10W - 30 and the lifter are making lots of random noise. Any suggestion of weight of oil to use or additives. The lifters are brand new Comp lifters on a XE268 cam. Also I have Comp roller rockers. They seem to be working well just noisy.
I got the exact same components in my engine, and I remember when I added the CC roller lifters I heard some lifter noise coming, when I called CC they said its normal to have that noise with the roller rockers, it doesn't make sense to me, but that what they said.
You have oil, so I suggest you look for correcting the noise. First thing that comes to mind is to check your lash. Posi-lock nuts used with the roller stuff have a bad habit of coming loose causing excessive lash and noise.
I was told the XE cams with flat tappets are going to make noise because of the opening and closing rates. I know my XE262 always made a little noise and this was the response I got from several folks on here. I ran heavier oil than 10-30 to quiet it down some though. Never had any problems out of the cam though.
Use the 15-40W HD Desiel oil from Castrol or Penziol - these oils have Zinc additive and they also contain cleaning agents. Camshafts with flat tappets need to have zinc in the oil.
I also use around 20-25 percent Lucas Oil stabilizer. I had a good friend here in Tallahassee tell me of this stuff ...
On my car, 4 Quarts oil, 2 quarts Lucas. No noise at all and the oil viscosity seems to stay more normal. Before using this combination my 454 would not have any valve train noise with new changes and then after a couple weeks of use and oil breakdown, the valve train noise comes back. I did an adjustment while running (when hot engine) and the noise would not go away.
Lucas and the better oil - no issues after a month of use, hot or cold.
Pulled the roller rockers tonight. The only thing I noticed was the tip of one valve had a part broken off. The sliver was still there and the valve looks a little lower, but after pushing down on it I think it is closing. Reinstalled the old rockers and will try and readjust this weekend. This time the valve covers will not go back on until all is working properly.
What you're probably hearing are your valves slapping shut. The ramps of the XE cams are too steep (opinion of many) and the valves literally slap shut. Search this site and others: "noisy XE cam" and you'll get some direction though not much can be done short of a new cam with reasonable ramps.