i have a 300ex bored 20 over, it knocked after i rebuilt it so i replaced the rocker arms, adjusted them, replaced the cam, and i just cant figure it our, when i was adjusting it to tdc compression stroke and it hangs a little, could i have the vavles to tight>

 

Sounds like you might have a deck height problem, that is the top of your piston might be contacting the head when it is at the top of it's stroke. I'm not real familiar with these smaller engines so I'm just going off of what little general engine knowledge I have. On VW engines this is fixed by shimming the cylinder up, maybe there is a similar cure for these, or a thicker head gasket. Hopefully one of the experienced mechanics will chime in and give you some REAL help[img]i/expressions/face-icon-small-smile.gif[/img]

When I was younger I had a VW that had an annoying knock similar to what you describe on one of the cylinders. It turned out to be a BB sized ball bearing in that cylinder-had a BUNCH of little indentations on the piston top and head in the combustion chamber when I finally pulled that head off...

 

it was making contact with the head, so i grinded the piston at the spots it was making contact and it runs fine.