Not even worth messing with really, what you can do tho is with the engine assembled, mark the bottom of the piston skirt that hangs down into the intake port then take the piston out and cut 5mm off the bottom of the skirt between the marks, don't leave any sharp corners and round everything off nice and smooth, this will give better intake duration and the engine will have a slight increase in power, this will also let you get the feel for your dremel since there's a decent amount of metal to remove so you can practice your technique. I prefer high rpm and a very light touch, just let the tool do the work and don't push down to try and make it cut more or faster. Use a steel or carbide bit for most the cutting then switch to a sanding drum for a smooth finish, turn the rpm down when using sanding drums... they do explode if you use too much rpm. Also, do NOT use the grinding stones on anything aluminum, I don't care what anyone else says about this, but the aluminum loads up in the stones then heat expands and they can explode without warning... wear safety glasses too... you never know when a small metal shaving will be headed straight for your eye until it happens...
Another good investment is a set of diamond coated burrs, these do best at high rpm with a very light touch and lubed with cutting oil or any oil is cutting oil isn't available, the diamond burrs are good for finishing and leave a smooth surface. You can get diamond coated burrs at harbor freight or off eBay for fairly cheap, and you can get a good set of carbide burrs off eBay for around $25 to $30, which is way cheaper than $10 or more each at home Depot or Walmart wherever they sell dremel bits. Harbor freight also sells those 100 piece or larger bit sets for like $20 so definitely worth getting there if you got one in your area.
