Ok this one has me stumped and I can't figure it out for the life of me! I was flooring it behind two friends of mine who were racing so I could get it on video. Then all of a sudden I heard this loud ticking/tapping sound and my clutch felt really funny. I pulled the clutch out and the disk was shot (broken springs etc) and the throw out bearing was bad so I replaced the whole setup. Well the sound was still there and it's loud as hell. I replaced the lifters and pushrods the next day thinking that was it. But the sound was still there strong as ever (consistant with revs). Sounds like a marble in the engine sometimes, then sometimes it goes away. A lot lighter sound at idle then gets a little louder when revved. The motor has 16000 miles on it with a cc306 cam. Hope I provided enough info sorry about the long post but I need help bad. Thanks

 

I'd replace the exhaust gaskets and go from there. I had a noise that I thought was valvetrain and it turned out to be a leaky gasket. Always try the cheap stuff first...

 

I have the same problem its a piston slapping the wall,yea spun bearing is my problem also look at the "383 motor problem " thread thats up now he has the same problem

 

Well I hope it's not a piston hitting the wall but the sound comes and goes and it's erratic and doesn't tap the same every time.