justin_o_guy2 wrote on 10/29/15 at 22:46:32:They are tuning for safety as they perceive it . Give one mechanical reason why the SPECIFICATIONS listed by the manufacture would lead to early demise. A RANGE of valve lash settings exists. Just as oil. Inside the high and low marks, accepted.
I at least postulated a theory as to Why the tight end is better for longevity. You quoted an unconfirmed consensus.
because looser lash gives more room for error
adjust loose and get it off a thousandth and you have a slightly tighter or looser clearance than you expected
Adjust for minimum clearance and get it wrong on the tight side and you get a non running motor and maybe a hole in your piston or burned valve
what do you prefer, loss of maybe a 1/4 HP, or loss of an engine?
I tend to go with the several thousand guys who say 'go loose'
though in truth I prefer the middle of the road valve lash, like Dave, that way I'm neither loose nor tight