I'm working on my brother's 85 cause he over heated the engine pretty bad. After doing some investigating we find out it has a bad lifter, #6E. When I tightened it a 1/4 turn the noise would go away for about 4 secounds then clack, clack, clack, all over again.

I replaced it with a new one, SOB, same thing.

I don't think it's a wiped cam lobe because I can physically see the rocker arms opening the valves. Also the lifter looked new when replaced. No wear on the bottom.

I forgot to mention, it's not a roller cam, flat tappet(lifter), 305.

 

pulled stud!

 

You know I read that on TGO! I'll check it out tomorrow when I get back from the drags. Thanks 12secondTA.

 

Well I checked the stud and it's fine. The clacking goes away when I add more preload but of course comes back. I talked to a CompCams rep at the drags and he was also baffled. He said the noise was the pushrod bouncing on and off the lifter. He said run it with Valvoline Racing oil 20w50. That should quite the noise down.

I'll take off the rocker arm and inspect it for damage later on.