dunno whther true or not, heard from someone before....but come to think logically it sounds okie:
when u left the engine long, the engine oil and water would subside. So after u crank your engine, all the parts would go into motion. You got to let it for a few minutes to get the engine oils to relubricate the parts and also the water to flow smoothly.
That is why my timing rely on my tappet sound. When the tappet sound goes smoother and close to no sound, that's when I go (meaning enough lubrication). Also depends on whether or not rushing, if rushing for time; than f*ck the idling.
Problem now is after I used Q8, there's no more tappet sound.............but I still wait, usually finish 1 ciggie.