i had a 4 cam turbo that had a smack on the drivers side
that broke 1 pulley and bent another one, it pulled the timing belt
so hard it pulled the threads outa shape holding some tensioners,
it had a new belt and pulleys/the block machining and tapping and by turning over by hand all seemed to be ok, so we started it and it was fine,still pooped meself though

on them engines,valves do valves not pistons into valves