This is a generic query, (not related to any particular engine), about valve lash adjustment. I've always been very meticulous about setting VL on engines that I tune and do it "by the book" but this question bothers me:
Most VL specs are @ TDC for each particular cylinder. Obviously, this is not at the furthest point from the lobe for each tappet. Usually, the cam looks like rabbit ears splayed at 10/2 o'clock or such. I've always assumed from this adjustment spec that it does not matter where on the round part of the cam you set clearance as long as you are not on the lobe or the *slight rise lead-up ramp* to the lobe that most cam profiles have.
I just set clearance on my MB diesel and TDC for #1 cylinder according to the crank pulley mark resulted in rabbit ears that were tilted pretty far off symmetrical, IOW, one lobe was pointing almost straight up and the other was pointing almost sideways. There is no problem w/ chain or sprocket, in fact chain was completely un-stretched according to timing marks and car runs great.
I chose to set the clearances as follows: I slowly turned motor by hand and set each individual VC on the engine as the lobe was pointing straight-up away from the tappet. I did not have time to re-check each one @ TDC for each cylinder but I will later. (The valve cover takes a whole 10 minutes to remove on these cars). The measurements should be the same, right?
To further complicate things, MB is one of those manufacturers that gives a hot and cold VC spec on the sticker under the hood, with over/under temperatures. The problem with that is that when I start the hot valve adjustment, the temp is definitely over the *hot minimum*, when I'm doing the last ones--not so much. Also, (and this has always confused me), the hot setting is .05mm larger than the cold spec. If valve clearances get LARGER as an engine heats-up, why isn't every VC spec in the world *half a mouse hair* cold?? Just use the thinnest feeler gauge on the tool setting them cold? I mean, if they get looser as they heat-up, what's the problem? I always thought that it was the other way around. 
Anywhoo... I always just set them as the spec says. I recently set them on my older Toyota Land Cruiser and the Haynes manual, (actually a very good HM for this vehicle), says to set them all with (2) different cam positions. IOW, put motor @ TDC #1 and set half the valves and then TDC #5 or 6, (can't remember), and set the remaining ones. This definitely related to my original question about lobe position.
Sorry for the long, neurotic question but I truly agonize over these OCD mechanical issues. Thanks in advance as always...
