Tick, tick, tick, tick, tick BOOM! Lifters ticking?

i got a 50.000milles motor and at the begin i didnt hear any ticking but a few months ago it started but is something very very little compared with the one i had before that i used to hear it from the inside of my house and when we open my old engine i found that the valves was sitting on the pistons there was gunk all over but the weird thing was that the motor wasnt smoking at all. the reason why i had get a new motor was a oil leak coming from the crankshaft seal and they couldnt get it fix because a few thing inside were broken