Optimal V/V timing - SQ4

[camstevens]

Hi
Would appreciate thoughts/experience on valve timing.
The very comprehensive (and essential!) valve timing guide from AOMCC suggests an inlet cam peak lift at around 105 deg ATDC, opening at 25 deg BTDC. My cam is pretty much new, but gives 115 deg peak at 24-25 deg BTDC opening.
Playing around, I’ve advanced the timing to within 110 deg peak and 30 deg BTDC opening. I could move timing to get closer to 105 peak, but this obviously results in a valve opening times in excess of 30 deg BTDC, of which I 'm not sure of potential longer-term effects.
Peak seems to be the favored indicator of ideal cam position. Not sure what option(s) is best on balance. Interestingly the differential lift from 105 deg to 115 deg (at peak) is very small at only a couple of thou or so, so I’m not sure if obsessing in peak location would have a massive effect.

Cam (my name, not the component )

[Roger Gwynn]

The position of the lobe centre is much more critical to correct valve timing than opening or closing because the valves are opening very slowly at the extremes so a few degrees one way or another will not make much difference. It is also easier to determine the position of the LCA accurately. I don't think it necessary on a softly tuned engine to go for high accuracy, yes if it was a highly tuned racing or even sporting engine.