Noisy valve train on start-up

You will find that the valve train will become less noisy over time as the clearances reduce..... this is due to the valve itself hammering into the seat during operation,therefore the clearances at the top of the stem,where the shim is reduces,when clearances are checked and found to be out of spec smaller shims are fitted to increase the gap to spec..... never heard a shimand bucket system get noisy.