How would "dimpling" the pistons help an engine?
Remember, the piston top has much less material to machine. I'm not saying you can't do it, just be careful. I use piston "dimples" where I drill a .050" deep divit with a 1/4" round tip rotory file. From there I cut a small trough aimed towards the plug. Where would you make these mods? I suggest looking at the carbon on the piston top and chamber itself and see where the burn is not uniform, plus good 'ol trial and error. I use these piston dimples to reduce detonation through agitation of the air/fuel mix.
So if you were to make these dimples over the entire surface of the piston, would this agitate the fuel enough to increase efficiency? Has anyone tried something like this?