Valve to Valve and Piston to valve checking LASH

When the engine is at operating temperature the components will heat up and clearances will change however the lash clearance on a solid lifter engine won't shrink to zero. Some amount of lash clearance is always required. For the example in the course, the Honda cams we used actually require the lash to be set to 0.30mm hot, not cold, hence this is a realistic interpretation for the sake of checking clearances. Certainly if you set the lash to zero you're going to be extra safe though. I guess for me this all comes down to how much clearance I'm comfortable with when I'm checking. Personally I'm usually quite conservative with my clearances.