tappin sound through certain rpms?

I just bought a new motor came out of a 99 eclipse and i crank it up and when it idles it has a faint tap then @3000 rpms its the loudest then after 3000 it dies down and sometimes quits can anyone tell me the problem?

ive been told it was the main bearings, and some people told me it was a rod knocking and people have also told me it was lifters tappin someone please help?

I have one other important question for anyone who can answer it? My 1997 talon 5 spd keeps shattering clutches its a stock 99 eclipse motor in it i just bought a brand new $250 zoom clutch and it shattered it the next day i may have did one burn out but other than that i was driving normal and it just broke...can someone please help me figure out the problem i have bought 3 clutches in 2 months and yes i do know how to drive they arent burning up the center is shattering....help?

please can someone help me figure the problem i just spent $1200 on this motor and i dont want it to mess up so help please??

no one knows the answer to these problems??

Tapping sound and shattering clutches is not a good sign.

Tapping could be any of your bearings failing and the shattered clutch could be from a warped flywheel or from bad main bearings so the crank is moving up and down and the tranny input shaft is trying to hold the clutch disk in 1 position when the crank is pulling it another way.

I would take and put pressure on the harmonic balancer and while doing that have someone step on the clutch, if the crank moves any noticable amount your bearings are fucked.