Just looking for data points here. The question is what is the maximum acceptable lash closure rate rate (or lobe velocity) for when a solid lifter lash is taken up on the valve opening. This would also the rate for when the valve closes.) This would be measured in inches per degree. I have a reference here that says up to .001" per degree is OK. How to Determine Lash And if you care to know, I am having some fits with some hydraulic lifters on another engine, and am thinking of putting solids in. I have profiled the cam in detail, and know the lobe velocity in detail. So I think I am fine (it is an old cam design with slooow initial and final ramps), but am just looking for any other data points on this. Tnx.