pinging noise

[project250x]

A while ago my 250x engine started to make a pinging noise inside the top end. I tore the engine apart and found out the rings were bad so i put in a new piston and rings and bored the cylinder .5 overbore and had new valves and seals installed. I had the engine started yesterday and it is still making the same noise, I was wondering if maybe a bad bearing or maybe bad valve springs would make a pinging noise like that. I know it isn't the gas because before i tore my engine apart it was running on 93 with stock compression and it made the same noise. Any ideas on what would make the engine make a pinging noise like that?

[sampleez]

cam chain could be worn out

[mojoe2878]

a bearing will cause it, did you not check the crank and rod bearings when you had it tore down and before you put a new piston on?
a weak valve spring can too, if it isnt letting the valve close all the way it will make a ticking noise.
i would do like sampleez said and check the timing tensioner and chain first since its the easy part to get to. make sure the tensioner piston isnt stuck or the spring inside of it hasnt weakend too much. when you retract the piston inside the tensioner and then let it go it should pop out quickly and with a "pop" noise. if it doesnt then replace it.