It seems the 110 LSA will keep the valve heads further from the crowns than the 108 LSA and this will allow shallower valve pockets and more compression. Does this make sense? It was figured out at midnight and hopefully the logic is sane.
Yes. You are doing fine, but I DO NOT recommend doing critical analysis when you are sleep deprived. Sleep deprivation does nothing positive for anyone.
How it works is: With equal timing and the center at TDC, the "tighter" the LCA, the
LESS valve to piston clearance that you have. "Opening up" the LCA retards the intake for more clearance, AND, advances the exhaust for more clearance. As you can see, it can get "tricky" quickly, when the timing is not equal to TDC.
2 degrees of cam change gains or loses valve to piston clearance depending on which direction you go. The rate per degree is equal to the net valve lift (or loss) per degree at that point on the flank lift curve. The maximum flank lift per degree is fixed by tappet diameter for "flat" tappet cams. This can be a significant amount, so you need to do a check at the mock up stage, OR, do a VERY accurate simulation.
On some engines, you also need to check on valve to valve clearance. On big valve Cosworth 4v engines, advancing the inlet cam REQUIRES advancing the exhaust cam just to maintain valve to valve clearance. It's not the best for power, but it is necessary to keep from "clashing the valves".
Most engines
may run better with the cam(s) 2 to 4 degrees advanced. Larger trapped volume from the early intake closing helps provide more torque, with little to no top end bhp penalty. BUT, when you get closer to the "optimum cam profile for the application", cam timing becomes "very fussy". "Long duration" cam grinds seem to benefit from this strategy more than "high intensity" cam grinds. Again, it is about the "trapping volume".
Where the closest point of valve to piston clearance is located, depends primarily on cam positioning (timing), BUT, Build Geometry (tm) does have influence on this critical performance parameter. Build Geometries which feature long piston dwell times at TDC can create fitment difficulties. It's the old: "Five pounds of crap in a three pound bag" problem.
And, achieving a suitably high compression ratio is ALWAYS a "dogfight" with small displacement engines, regardless of whether they are big valve or small valve. It's never a problem on a 632 cubic inch BBC, but it's always difficult below 122 cubic inches . . . . .
BTW, IMHO, if your engine runs better with the cam(s) more than 4 degrees from what is recommended, you need a different cam or cams, or possibly: "more development".Hope this helped . . . . . .