My brother in law just put together an engine and can not get the lifters to quiet down. He called summit and they set him another camand lifters and still has the same problem. I was hopeing that you guys might be able to help. I think that there is a valve train binding or interference issue but he thinks he got another set of bad lifters. The engine has flat top pistons with one valve relief and the largest lunati voodoo cam they make. It is right at 600 lift. I really hope some body has some ideas.

 

Was the valve train geometry checked ?