Alright so i was at the drag strip, made 2 passes, went for gas, came back and heard some knocking from the engine. Fast, fairly loud. but oil pressure good and no metal shavings in oil. Had it towed home, towed it into class to maybe get an opinion on what it might be, started it up and there was no knock.. let it idle, reved it up, nothing.. for about 20 min it was just how it was supposed to.. then bam all of a sudden it starts up, then started to fade away, then started again.. sounded louder underneath the car, so i shut it down.. an instructor told me it could be timing chain loose.. tore the whole thing down and nothing wrong.. rocker arms good.. lifters good, pushrods strait and clear, cam bearings are good..oh and on a side note, the engine has roughly 7000 miles on a total rebuild. but here is where i messed up, i listened to my instrustor as opposed to diagnosing it properly, i.e taking the belt off and starting, cutting out cyl, compression testing... so now its sitting in a friends garage half torn apart and not sure what my next move should be.. renting and engine lift and start tearing into the bottom end? or put it all back together getting all new gaskets and doing it right.. anyone had an intermitten knock before? any suggestions would be greatly appreciated